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Authors
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Poster Title and Abstract
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Allen R. C. Vines S. K. Wilson L. B. III Borovsky J. Ho G. C. Jian L. K. Li G. Lugaz N. Maruca B. Verscharen D. Vievering J. Wimmer-Schweingruber R. F.
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The Need to Investigate the Variability and
Multi-Scale Nature of the Solar Wind and Its Impact on
Energetic Particles [#2109]
Recent missions with separations ranging from small scale, such as MMS
and Cluster, to large scale, such as STEREO, demonstrate clear variability
and coupling of processes and structures in the solar wind across a wide
range of spatiotemporal scales. These new findings push our current
understanding beyond the abilities of traditional single-point solar wind
measurements. Studies using such single-point observations generally do not
allow for deeper investigations of cross- and meso-scale dynamics and plasma
variability of the solar wind, nor do they allow for the exploration of
sub-structuring of large-scale structures and transients like the
heliospheric current sheet, coronal mass ejections, and co-rotating interaction
regions. The few multi-point solar wind measurements available to date either
span very large scales (i.e., 10s of degrees in the case of the STEREO
mission) or very small spatial scales (i.e., ion kinetic scales and below in
the case of MMS and Cluster observations upstream of the Earth’s bow shock).
These measurements have hinted at a dynamic solar wind consisting of complex
and intertwining flux tubes that are largely responsible for the variability
and cross-scale coupling of the solar wind and the dynamics and evolution of
transients. However, lacking measurements at intermediate scales has
prevented a clear understanding of the variability and the sub-structure of
the solar wind and transients. This intermediate scale – the meso-scale – is
crucial for understanding the connection of the corona to an observer
anywhere within the heliosphere, as well as for revealing the currently
unresolved physics regulating particle transport, magnetic field topology,
and the causes for variability in composition and acceleration of solar wind
plasma. To fill these outstanding gaps in our understanding of the
fundamental multi-scale structure and variability of the solar wind, new
missions are needed to investigate the solar wind as well as its associated suprathermal and energetic particle content, over a range
of mesoscale separations which lie in-between the large-scales
measured by STEREO and the small turbulent scales to be investigated by HelioSwarm. This poster will focus on the outstanding
science questions currently out of reach of current and past heliospheric
missions, as well as the fundamental advance that understanding these scales
would present to the heliophysics community as a whole.
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Alterman B. L. Desai M. I. Christian E. R. de Nolfo G. A. Ogasawara K. Kanekal S. G. Randol B.
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Closing Our Mesoscale Knowledge Gap:
Using the Space Weather Advanced Notification System (SWANS) to
Disentangle Mesoscale Temporal and Spatial Variation in the Solar Wind [#2160]
By
2050, Heliophysics needs to understand and have disentangled the spatial and
temporal variability of mesoscale (100s km to 10e6 km) structures in the
solar wind. This knowledge will fundamentally transform our understanding of
solar wind mass, momentum, and energy transport. Furthermore
it closes the knowledge gap necessary to enable high fidelity space weather
prediction and forecasting. In this presentation, we discuss the Space
Weather Advanced Notification System (SWANS). SWANS combines a prime carrier
spacecraft with six CubeSats/SmallSats in large
Distant Retrograde Orbits (DROs). The prime spacecraft carries the six
CubeSats/SmallSats, Δv
necessary to transport the entire mission into DRO, and the primary antenna
for communication with Earth. Upon reaching the target orbit, the prime
spacecraft launches the six CubeSats/SmallSats,
which spread out to provide continuous and simultaneous solar wind
observations across a range of longitudes. SWANS provides the mesoscale
observations critical to advance our scientific understanding of solar wind
structures and to close the knowledge gap required for mesoscale space
weather forecasting.
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Alterman B. L. Kasper J. C. Leamon R. J. McIntosh S. W. Stevens M. L. Wilson L. B. III
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Solar Wind Helium Measurements Demonstrate the
Importance of Unified and Consistent Long Duration In
Situ Plasma Data [#2064]
Long
duration L1 missions and integrated data sets provide unique insight into the
Sun and solar wind. This work combines in situ measurements of the solar wind
helium abundance over multiple solar cycles along with EUV measurements from
SDO and SOHO to derive two unique insights about solar wind formation. First,
we use in situ Wind plasma measurements cover 22+ years to derive key insight
into solar wind acceleration and generation above the photosphere. Second, we
combine OMNI/Lo data from 1974 through the present day with SOHO and SDO EUV
Brightpoint measurements to identify an in situ
marker that predicts the onset of a new solar cycle in a manner that is
likely related to physics below the photosphere. Each of these results has
been enabled by long duration missions and/or data sets that cover time
periods markedly longer than a typical Phase E, a mission’s prime
science phase.
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Arge C. N. Jones S. Henney C. J. Schonfeld S. Vourlidas A. Posner A. Muglach K. Luhmann J. G. Wallace S. Zhang J. Leisner A. St Cyr O. C.
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Multi-Vantage-Point Solar and Heliospheric Observations to Advance
Physical Understanding of the Corona and Solar Wind [#2085]
The
launch of the twin STEREO spacecraft in 2007 allowed for the first
simultaneous global views of the Sun in the extreme ultraviolet (EUV). It
also permitted simultaneous sampling of the solar wind from widely spaced
points in the ecliptic, as well as stereoscopic views of the Sun’s corona in
white light (WL) and EUV. Virtually all corona and solar wind models are
driven by global estimates of the photospheric
magnetic field. Other data sources, such as EUV, WL, and in situ plasma data
are essential for both validating and constraining these models.
Unfortunately, the STEREO mission payload did not include magnetographs, so
the opportunity to simultaneously measure the Sun’s global magnetic field has
not been possible until the recent launch of Solar Orbiter (SolO). Vector magnetographs onboard the Solar Dynamics
Observatory (SDO) and SolO spacecraft will, on rare
occasions, allow for nearly complete 360° coverage of the Sun’s surface
magnetic field. It is argued in this poster that to significantly advance
basic understanding of the corona and solar wind, it is essential to have
continuous monitoring of the Sun’s global magnetic field distribution, along
with equivalent coverage in EUV and WL, as well as in situ monitoring of the
solar wind from multiple and widely spaced vantage points.
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Awasthi A. K. Liu R.
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Small-Intensity-Class Flares Unveiling the
Magnetic Environment of Solar Eruptive Processes [#2005]
Solar
flares are transient bursts occurring in the solar atmosphere. In particular, small-intensity-class flares unveil the
magnetic environment of the source region of solar eruptions. In this
context, I will present an investigation of the source region of complex
ejecta, focusing on a flare precursor with definitive signatures of magnetic
reconnection, i.e., nonthermal electrons, flaring plasma, and bidirectional
outflowing blobs. Aided by nonlinear force-free field modeling, we concluded
that the reconnection occurs within different branches of a multi-flux-rope
system. I will continue on with presenting another
case of a micro-flare that drove disturbances in a filament. Filament
material predominately exhibited two kinds of motions, namely, rotation about
the spine and longitudinal oscillation along the spine. The composite motions
of filament material suggested a double-decker host structure, comprising of
a flux rope atop a sheared-arcade system. Thus, it is evident that since
flares are the earliest observational signature of solar eruptions that drive
space-weather, their investigation not only unravels the physics of plasma
heating and particle acceleration mechanisms, it
also improves our capability of predicting its impact on the Earth by
unveiling the pre-eruptive environment.
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Bastian T. S. Murphy E. J. Chen B. Fleishman G. D. Gary D. E. Glesener L. Nita G. M. White S. M.
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Solar and Heliospheric Physics with the Next Generation VLA (ngVLA) [#2024]
The
next-generation Very Large Array (ngVLA) is an
advanced concept of the National Radio Astronomy Observatory for a
general-purpose ground based astrophysical observatory operating at radio
wavelengths. It is designed to perform high resolution imaging and
spectroscopy using the mature techniques of Fourier synthesis imaging. It
will observe from 1.2–116 GHz (0.26-25 cm) using 214 × 18m antennas
distributed in the main array out to baselines of 1000 km, and 30 × 18m
antennas distributed in a long baseline array extending to baselines of 8860
km. A short baseline array of 19 × 6m antennas completes the suite of
antennas. The telescope will be ten times the sensitivity of the Jansky VLA
and ALMA and will have ten times the angular resolution. Key science goals
include unveiling the formation of solar-system analogs on terrestrial scale;
probing the initial conditions for planetary systems and life with
astrochemistry; charting the assembly, structure and evolution of galaxies
from the first billion years to the present; using pulsars in the galactic
center to make a fundamental test of gravity; and understanding the formation
and evolution of stellar and supermassive black Holes and compact objects in
the era of multi-messenger astronomy. Solar and heliospheric physics are also
important components of the ngVLA science program.
The large number of antennas and the dense sampling they provide in the main
array will enable high-fidelity imaging of solar phenomena from the
chromosphere up into the corona. Of particular interest are chromospheric and coronal magnetic fields, magnetic
energy release, particle acceleration and transport, and shock formation and
evolution. The ngVLA will also be a superb
instrument to observe spacecraft beacons and natural radio sources to study
propagation phenomena such as angular and spectral broadening,
scintillations, and Faraday rotation. These may be used to study solar wind
acceleration, solar wind turbulence and its evolution, turbulence
dissipation, and the interaction of solar wind with transient events such as
coronal mass ejections. The ngVLA will be a
powerful complement to the in situ and remote sensing observations of the
next generation of NASA heliophysics missions.
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Bastian T. S. Barta M. Brajsa R. Chen B. De Pontieu B. Fleishman G. D. Gary D. E. Hales A. Hills R. Hudson H. Iwai K. Kobelski A. Krucker S. Loukitcheva M. Motorina G. Shimojo M. Skokic I. Wedemeyer S. White S. M. Yan Y.
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Solar Physics with the Atacama Large
Millimeter-Submillimeter Array (ALMA) [#2044]
The
Atacama Large Millimeter-submillimeter Array (ALMA) is a Fourier synthesis
telescope operating at millimeter and submillimeter wavelengths. Located in
the Atacama Desert of Northern Chile and an elevation of 5000m, and operated
by an international partnership, ALMA opens a new window onto the Universe.
The ability to perform high resolution continuum imaging and spectroscopy of
astrophysical phenomena at mm-submm wavelengths with unprecedented
sensitivity opens up new avenues for the study of
cosmology and the evolution of galaxies, the formation of stars and planets,
and astrochemistry.
ALMA also opens a new window into solar physics. Unlike many diagnostics at
optical and ultraviolet wavelengths — spectral lines that form under
conditions of non-LTE — the source function is Planckian for mm-submm
continuum emission from the Sun. These wavelengths form mainly in the poorly
understood solar chromosphere. This turbulent layer channels the energy from
the solar interior into the heliosphere, thus mediating all “space weather.”
ALMA provides powerful new diagnostics of the solar chromosphere that are
complementary to those provided at optical and UV wavelengths. Beginning in
late 2016, ALMA became available for studies of the Sun in the 1.25 mm (band
6) and 3 mm (band 3) continuum bands with an imaging cadence of 2 s. Both
interferometric imaging and fast-scan total power maps of the entire solar
disk are available. Since then, observations at 0.85 mm (band 7) and 1.77 mm
(band 5) have been commissioned for solar observing. It is expected that 3 mm
polarimetry and fast-scan regional mapping will become available in the
coming year. Plans are underway to commission ALMA for flare observations
within two years. ALMA is expected to
be the premier mm-submm observatory for several decades to come and, as such,
is an important ground-based complement to NASA heliospheric missions.
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Bourouaine S. Perez J. C. Klein K. G. Chen C. H. K. Martinović M. Bale S. D. Kasper J. C. Raouafi N.
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Turbulence Characteristics of Switchback and Nonswitchback
Intervals Observed by Parker Solar Probe [#2120]
Using
PSP data we analyzed the characteristics of solar wind turbulence during the
first solar encounter covering radial distances between 35.7 SR and 41.7 SR.
In our analysis we isolate so-called switchback (SB) intervals (folded
magnetic field lines) from nonswitchback (NSB)
intervals, which mainly follow the Parker spiral field. Using a technique
based on conditioned correlation functions, we estimate the power spectra of
Elsasser, magnetic, and bulk velocity fields separately in the SB and NSB
intervals. In comparing the turbulent energy spectra of the two types of
intervals, we find the following characteristics: (1) The decorrelation length of the minor
Elsasser field is larger in the NSB intervals than the one in the SB
intervals; (2) the magnetic power spectrum in SB intervals is steeper, with
spectral index close to –5/3, than in NSB intervals, which have a spectral
index close to –3/2; (3) both SB and NSB turbulence are imbalanced with NSB
having the largest cross-helicity, (4) the residual energy is larger in the
SB intervals than in NSB, and (5) the analyzed fluctuations are dominated by Alfvénic fluctuations that are propagating in the sunward
(antisunward) direction for the SB (NSB)
turbulence. These observed features provide further evidence that the
switchbacks observed by PSP are associated with folded magnetic field lines
giving insight into their turbulence nature.
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Caspi A. Shih A. Y. Athiray P. S. Warren H. P. Winebarger A. R. Cheung M. C. M. DeForest C. E. Gburek S. Klimchuk J. A. Kowaliński M. Laurent G. T. Mason J. P. Mrozek T. Palo S. E. Schattenburg M. Seaton D. B. Stęślicki M. Sylwester J. Woods T. N.
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Understanding Heating of the Solar Corona
Through Soft X-Ray Spectroscopy [#2095]
Why the
solar corona is orders of magnitude hotter than the underlying atmosphere
remains a fundamental unanswered question in solar and stellar physics. Soft
X-ray (SXR) emission provides unique diagnostics, not available from other
wavelengths, of high-energy processes in the corona. However, despite the
rich insights enabled by spectrally resolved SXR measurements, such
observations of the Sun have been sporadic, with incomplete wavelength
coverage of the crucial 0.25–3 keV (4-50 Å) range and with significant
compromises between spectral, spatial, and temporal resolution. Emerging
advances in detectors, focusing optics, diffraction gratings, and other
technology offer both near- and long-term capabilities to completely fill
this observational gap with imaging spectroscopy at high resolution,
sensitivity, and cadence. Significant progress on this critical question —
and other closely related questions — is easily achievable by 2050 if we leverage
these advances and prioritize development of new solar
SXR observatories.
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Chamberlin P. C.
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Next Generation Formation-Flying White Light Coronagraphs
for Science [#2028]
Conventional
solar coronagraphs measure visible photospheric
light Thomson-scattered by coronal electrons. Due to on-disk light
diffracting off the external occulter and vignetting effects, historical,
current, and near-future single spacecraft coronagraph measurements do not
properly resolve the low corona where CME initiation and acceleration occurs and the Solar Wind is formed. Increasing the
distance between the external occulter and optical elements will greatly
improve the imaging resolution and reduce the noise in the low corona. Taking
advantage of recent technological improvements in formation flying have
enabled large distances and accurate positioning between two spacecraft
possible, and once utilized will lead to improving our understanding of coronal
evolution and how the solar wind and CME transients evolve from the low solar
atmosphere through the heliosphere.
The 6U CubeSat, the Spherical Occulter Coronagraph CubeSat (SpOC Cube), was developed to observe the low corona in
white light from 1.5RSun to 5RSun. SpOC will deploy
an 8cm diameter free-flying spherical occulter, and after deployment the
actively controlled CubeSat will provide inertial formation flying with the
sphere and Sun. SpOC has greater than 2.25 m
separation between the occulter and optics, longer than STEREO Cor2, which is
approximately 1.3 m (Howard et al., 2008) and SOHO/LASCO C2 that is about 0.8
m (Brueckner et al., 1995). This larger separation improves
signal-to-noise due to reduced diffraction intensities off the occulter, a
dominant noise source in coronagraphs, and improves upon spatial resolution
of current coronagraphs.
An Earth-escape orbit is necessary and ideal, as it will take SpOC out of the influence of Earth’s atmospheric density
variations and changing gravitational forces, simplifying formation flying
while providing a 100% view of the Sun. Additionally, SpOC
Cube is a pathfinder directly scalable to future Explorer-class coronagraphs,
SpOC Ex, with even larger separations, possibly
hundreds of meters using high-TRL inflatable spherical occulters up to, or
even greater than, 100m in diameter. SpOC Ex will
have better signal/noise and true spatial resolution of better than 1 arcsec
all the way down to <1.05 solar radii.
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Chen B. Bastian T. S. Gary D. E. Saint-Hilaire P. White S. M.
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A Next Generation Radio Heliograph: New Insights into the Physics of the
Active Sun [#2084]
A
long-term goal of the solar and space physics community is to understand the
fundamental physical processes underlying solar flares and coronal mass
ejections (CMEs) and their space weather implications. Pertinent outstanding
challenges include the measurement of the dynamic coronal magnetic field, the
examination of physical mechanisms underlying the fast magnetic energy
release and efficient particle acceleration, and the understanding of the
formation and evolution of CMEs/CME-driven shocks.
Radio observations provide a wealth of unique tools for diagnosing both the
quiescent and active Sun. Outstanding examples include coronal magnetography of active regions, flares, and CMEs based
on radio gyromagnetic radiation; tracing and measuring flare/CME shocks and
the nonthermal electrons they produce; as well as origins of space weather
drivers such as fast CMEs, fast solar wind streams, and critical inputs on
the source components contributing to the F10.7 Activity Index.
In the past decade, thanks to the advances in radio frequency (RF) and
digital technologies, we have enjoyed a major transition in radio observing
techniques as it evolves from imaging at a few discrete frequencies to true
broadband dynamic imaging spectroscopy. In recent years, exciting new results
have emerged with the operation of new/upgraded instruments such as EOVSA,
JVLA, LOFAR, MWA, and ALMA. However, solar-dedicated instruments currently
operating or being commissioned do not have sufficient bandwidth, dynamic
range, and resolution to fully exploit the unique diagnostic power of
observations at radio wavelengths. This poster discusses the potential for
new insights enabled by the superior spectral imaging capabilities of a
next-generation radio heliograph such as the Frequency Agile Solar Radiotelescope (FASR) concept. Its synergy with other
multi-wavelength instruments (ground-based and spaceborne) and next-generation
numerical models will also be discussed.
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Criscuoli S. Kazachenko M. Kosovichev A. Martinez Pillet V. Nita G. Sadykov V.
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Challenges and Advances in Modeling the Solar Atmosphere [#2154]
Unprecedented
observations of the solar atmosphere and heliosphere will be provided in the
next decade by new ground- and space-based instrumentation. The synergy
between modeling effort and comprehensive analysis of observations is crucial
for the understanding of the physical processes behind the observed phenomena.
However, the unprecedented wealth of data on one hand, and the complexity of
the physical phenomena on the other, require the development of new
approaches in both data analysis and numerical modeling. This contribution
summarizes recent numerical efforts to reproduce the structure and dynamics
of the solar atmosphere, outlines challenges we
expect to face for the interpretation of future observations, and provides
recommendations to promote the development of more sophisticated models on
one hand, and foster the inter-comparison between models and observations on
the other.
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Daughton W. Cohen C. M. S. Phan T. D. SolFER Collaboration
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Ion Heating and Acceleration in
Impulsive Flares [#2111]
Ions
gain a significant fraction of the magnetic energy released in solar flares.
However, the mechanisms for ion energy gain remain uncertain as do the
conditions which may contribute to specific spectral and compositional
characteristics and their variability. While observations of the resulting
energetic ion population have been made for decades near 1 AU, relating these
directly to the acceleration processes and environment at the Sun remains
difficult. With recent advances in simulations and new observational
capabilities, the time is ripe for significant progress to be made. The NASA
DRIVE science center on Solar Flare Energy Release (SolFER,
solfer.umd.edu) is bringing together a diverse group of scientists, including
theorists and modelers and observers doing remote as well as in situ
measurements, to address the full range of topics relevant to ion heating and
acceleration.
PIC simulations are already, for the first time, revealing the simultaneous
formation of electron and ion powerlaw
distributions, including the critical low energy cutoff of the powerlaw that controls the energy content of non-thermal
ions. The kglobal simulation model, which has been
successful in producing the extended powerlaw
distributions of non-thermal electrons, is being upgraded to include particle
ions and will pave the way for modeling of flare ion acceleration in
realistic global magnetic geometries. In-situ ion measurements over energy
ranges extending down to tens of keV and obtained by multiple spacecraft at
more unique locations (including inside 0.3 AU) are becoming available.
Measurements of ion spectra in energetic magnetotail reconnection events also
provide critical data. These data create the opportunity to test the
simulation results and examine the specific spectral and compositional
signatures that the models produce.
Models suggest that the magnetic geometry of flare energy release, and
specifically the strength of the ambient guide field, controls the production
of the most energetic particles in flares. Remote sensing observations
capable of revealing the magnetic structure of sites of energy release in the
corona are coming online, providing new opportunities for benchmarking models
with observations.
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Gibson S. E. Malanushenko A. de Toma G. Tomczyk S. Reeves K. Tian H. Yang Z. Chen B. Fleishman G. Gary D. Nita G. Pillet V. M. White S. Bak-Steslicka U. Dalmasse K. Kucera T. Rachmeler L. A. Raouafi N. E. Zhao J.
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Untangling the Global Coronal Magnetic Field with Global
Multiwavelength Observations [#2041]
Magnetism
defines the complex and dynamic solar corona. Coronal mass ejections (CMEs)
are thought to be caused by stresses, twists, and tangles in coronal magnetic
fields that build up energy and ultimately erupt, hurling plasma into
interplanetary space. Even the ever-present solar wind possesses a
three-dimensional morphology shaped by the global coronal magnetic field,
forming geoeffective corotating interaction regions. CME evolution and the
structure of the solar wind depend intimately on the coronal magnetic field,
so comprehensive observations of the global magnetothermal atmosphere are
crucial both for scientific progress and space weather predictions. Although
some advances have been made in measuring coronal magnetic fields locally,
synoptic measurements of the global coronal magnetic field are not yet
available. We present the state of the art and argue that there is a great
need to expand capabilities for measuring the global, synoptic coronal
magnetic measurement at all wavelengths.
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Gopalswamy N. Kucera T. A. Leak J. E. MacDowall R. J. Wilson L. B. III Kanekal S. G. Gong Q. Golub L. DeLuca E. Tadikonda S. S. K. Seaton D. B. Savage S. Winebarger A. R. Reeves K. DeForest C. Pevtsov A. Hurlburt N. Desai M. I. Bastian T. Lazio J. Jensen E. A. Manchester W. C. Wood B. Kooi J. Wexler D. B. Bale S. D. Tripathi S. C. Jain K.
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The Multiview Observatory for Solar Terrestrial
Science (MOST) [#2039]
The
Multiview Observatory for Solar Terrestrial Science (MOST) is a comprehensive
mission concept to understand the solar drivers and the heliospheric
responses as a system, discerning and tracking three-dimensional magnetic
field structures, both transient and quiescent, from the solar interior out
to 1 au. The full MOST scientific payload consists of the following
instruments designed to study the magnetic connection between the solar
interior and the atmosphere: (1)
Magnetic and Doppler Imagers (MaDI), which will
investigate surface and subsurface magnetism by exploiting the combination of
helioseismic and magnetic-field measurements of the
photosphere; (2) Inner Coronal Imager in EUV (ICIE) to study large-scale
structures such as active regions, coronal holes and eruptive structures by
capturing the magnetic connection between the photosphere and the corona to
about 3 solar radii; (3) Hard X-ray Imager (HXI) to image the non-thermal
component of flares; (4) White-light Coronagraph (WCOR) that seamlessly
connects the ICIE features into the near-Sun interplanetary medium up to 15
solar radii; (5) The Faraday Effect Tracker of Coronal and Heliospheric
structures (FETCH) is a novel radio package to directly measure the magnetic
field of the quiet solar wind, coronal mass ejections, shock sheaths, and
stream interaction regions. within 0.5 au; (6) Heliospheric Imager with
polarization capability (HIP) to track solar features into the heliosphere
and study their impact on Earth; and (7) Radio and Plasma Wave instrument
(M/WAVES). MOST will carry three in-situ instruments to support solar
heliospheric system science and advance solar wind physics: (8) Energetic
Particle Detector (EPD), (9) Solar Wind Magnetometer (MAG), and (10) Solar
Wind Plasma Instrument (SWPI). The MOST mission consists of two large
spacecraft with two identical payloads deployed at L4 and L5 and two smaller
spacecraft ahead of L4 and behind L5 to carry additional FETCH elements. MOST
will build upon the achievements of the Solar Heliospheric Observatory (SOHO)
and the Solar Terrestrial Relations Observatory (STEREO) missions over the
past couple of decades. In particular, the multiview
observations provided by STEREO and SOHO combined helped the community to
discern the three-dimensional nature of the quiescent and transient magnetic
structures in the support solar heliospheric system. MOST will expand this multiview observational approach into the first half of
the 21st Century.
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Guo F.
Chen B.
Reeves K. K.
Phan T. Glesener L.
Oka M. Gary D. Arnold H. SolFER Collaboration
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Electron Heating, Acceleration, and Transport in Solar Flares [#2096]
Solar
flares show the prolific production of energetic electrons with energy
content comparable to the released magnetic energy. The resulting hard X-ray
and microwave emissions show nonthermal signatures suggestive of power-law
electron energy spectra, but it remains unclear what controls the transition
and partition between thermal and nonthermal distributions. How electrons
efficiently gain energy remains a hotly debated problem. In addition, it is
not clear where the acceleration site is and what role the transport plays in
the acceleration, or in the emissions observed over space and time.
The NASA funded SolFER (Solar Flare Energy Release)
DRIVE Science Center brings together a diverse group of observers, theorists,
and modelers to attack these problems using a wide range of observations and
numerical tools. Particularly, EOVSA, RHESSI, SDO, and other multi-wavelength
observations provide the first measurements of energetic electron distributions
over space and the magnetic structure and plasma flows, with an excellent
agreement with MHD models. A set of heroic PIC simulations have demonstrated
clear power-laws of both electrons and ions, and an injection process that
controls the lower energy cutoffs. The first self-consistent macroscopic
model has achieved power-law electron distributions over nearly three decades
and has been applied to observations of the 2017 Sep. 10 event, with the
prediction that the efficiency and spectral index critically depend on the
guide field.
Achieving a decisive understanding of electron energization and transport
calls for further development of such center-scale collaborations. A fully
upgraded macroscopic energetic particle model coupled with realistic MHD simulations
is needed to robustly predict spatial and temporal energetic electron
distributions and, in turn, to compare with multi-wavelength observations.
Equally important is the development of remote-sensing instruments at
multiple wavelengths that can provide high cadence, high resolution, high
sensitivity, and high dynamic range imaging and spectroscopy of emissions
from energetic electrons. Such missions recently proposed or under
development include MUSE, Solar-C/EUVST, FIERCE, MaGIX,
FASR, and PhoENiX, etc. Direct observations of
energetic electrons from impulsive flares or reconnection events in the solar
wind and the Earth’s magnetotail by PSP, SO, MMS, and other future spacecraft
will also provide crucial data to probe the electron energization.
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Illarionov E. A. Sitdikov D. U. Kosovichev A. G. Tlatov A. G.
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Machine-Learning Framework for Construction and
Segmentation of Coronal Holes Synoptic Maps [#2015]
Fast
and reliable automatic pipelines for data processing and interpretation are
an essential part in space weather prediction models. We present an
open-source framework https://github.com/observethesun/helio for construction
of solar synoptic maps from SDO/AIA, SOHO/EIT and GONG/SUVI data, training a
neural network coronal holes (CHs) segmentation model from daily solar disk
images and model application to CHs identification in synoptic maps. The
continuously updated catalogue of solar synoptic maps built from SDO/AIA
images is available at https://sun.njit.edu/coronal_holes starting from the beginning
of SDO observations. At the moment we prepare an
extension of the catalogue based of SOHO data archive. In the presentation we
also discuss a correlation between SDO and SOHO synoptic maps over a common
period of observations as well as physical properties of CHs identified.
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Inglis A. R. Kirk M. S. Attie R. Pesnell W. D. Knoer V.
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Rapid-Cadence EUV and UV Imaging of the Solar Atmosphere: Science and Challenges [#2081]
The
modern era of solar EUV imaging, in particular a decade of SDO/AIA
observations, has unlocked a wealth of scientific discovery. Looking to the
future, a strong case can be made for ultra-high cadence, ultra-high
resolution Solar EUV and UV imagery. In this poster we present an overview of
the outstanding science questions driving such observations, explore key
science and technological requirements, and discuss the challenges of
achieving these requirements. Fast EUV imaging capability is especially relevant
for understanding bright, transient events on the Sun such as solar flares.
Models predict and observations show that during flares reconnection and
particle acceleration processes can occur on less than 1s timescales. These
energetic processes lead to rapidly varying thermal responses in chromospheric and coronal plasma. At present, these
atmospheric responses cannot be observed at the necessary spatial or temporal
resolution to fully explore the physics driving the eruptions, hence a key
potential diagnostic of solar energy release is unavailable. High resolution
observations bring with them significant technical challenges, including the
need for sophisticated on-board event triggering software, dynamically
avoiding detector saturation, and managing very high data volumes. This work
discusses the scientific potential of a high speed EUV imager as well as some
of the ways to overcome the current challenges.
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Kasper J. C. Lazio T. J. W. Romero-Wolf A.
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The Sun Radio Interferometer Space Experiment (SunRISE) Mission [#2013]
The Sun
Radio Interferometer Space Experiment (SunRISE)
will reveal aspects of how solar energetic particles (SEPs) are accelerated
at Coronal Mass Ejections (CMEs) and how SEPs are released into
interplanetary space. SunRISE is a constellation of
small spacecraft operating as a radio interferometer to produce a synthetic
aperture. As the first low radio frequency interferometer in space, SunRISE will provide spatially and temporally resolved
observations of decametric-hectometric (DH, < 15
MHz) radio bursts that cannot be observed on Earth due to ionospheric
absorption. DH radio bursts are produced by electrons energized near
expanding CMEs (Type II) and released by solar flares into space (Type III).
Tracking DH Type II radio bursts from 2 RSun to 20 RSun will allow discrimination of competing hypotheses
for the source mechanism of CME-associated SEPs by measuring the location of
Type II radio emission relative to where the most intense acceleration
occurs. Questions to be addressed include where electron acceleration and DH
Type II radio bursts occur relative to the overall structure of CMEs,
determine if specific properties of CMEs lead to DH radio bursts, and how the
magnetic connection between the location of the radio burst and an observing
spacecraft influences the detection of SEPs.
Tracking DH Type III radio bursts will determine if a broad magnetic
connection between active regions and interplanetary space is responsible for
the wide longitudinal extent of some flare and CME SEPs by imaging the field
lines traced by Type III bursts from active regions through the corona. SunRISE observations will reveal the topology of magnetic
field lines between active regions into interplanetary space and the time
variation of that connection, identifying whether some active regions connect
to a broad range of latitudes and longitudes.The SunRISE mission leverages more than 50 years of
development in ground-based very long baseline interferometry (VLBI)
techniques, and recent mission-enabling advances in software-defined radios,
GPS navigation and timing, and small spacecraft technologies. The SunRISE mission utilizes commercial access to space, in
which the SunRISE spacecraft will be carried to
their target orbit as a secondary payload by a larger host spacecraft.Part of this research
was carried out at the Jet Propulsion Laboratory, California Institute of
Technology, under a contract with the National Aeronautics and
Space Administration.
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Kaur S.
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Primary Drivers of Intense, Major, and Minor Geomagnetic Storms During
the Solar Cycles 23–25 [#2103]
The
individual and accumulated effects of solar features such as Coronal Mass
Ejections, Solar Flares, Solar Wind Plasma, Solar Type II Radio Bursts, and
Interplanetary Magnetic Field (Bz) have
statistically studied to understand the primary drivers of Geomagnetic storms
of Intense if (Dst < –100nT), Major if (–50n T≥ Dst ≥ –100nT), and Minor if (–20nT
≥ Dst ≥ –50nT) observed during the
solar cycles 23–25(ongoing).
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Kerr G. S. Alaoui M. Allred J. C. Bian N. H. Dennis B. R. Emslie A. G. Fletcher L. Guidoni S. Hayes L. A. Holman G. D. Hudson H. S. Karpen J. T. Kowalski A. F. Milligan R. O. Polito V. Qiu J. Ryan D. F.
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Solar Flare Energy Partitioning and Transport —
The Gradual Phase [#2020]
Solar
flares are a fundamental component of solar eruptive events (SEEs; along with
solar energetic particles, SEPs, and coronal mass ejections, CMEs). Flares
are the first component of the SEE to impact our atmosphere, which can set
the stage for the arrival of the associated SEPs and CME. Magnetic
reconnection drives SEEs by restructuring the solar coronal magnetic field,
liberating a tremendous amount of energy which is partitioned into various
physical manifestations: particle acceleration,
mass and magnetic-field eruption, atmospheric heating, and the subsequent
emission of radiation as solar flares. To explain and ultimately predict
these geoeffective events, the heliophysics community requires a
comprehensive understanding of the processes that transform and distribute
stored magnetic energy into other forms, including the broadband radiative
enhancement that characterises flares.
This poster discusses energy transport during the gradual phase of flares.
The precipitation of accelerated nonthermal electrons is thought to be the
primary vehicle by which flare energy is transported during the impulsive
phase, known from the presence of hard X-ray footpoint
sources. This is followed by the longer duration gradual phase, during which
flare emission decays and there is a lack of HXR emission (i.e.
nonthermal electron bombardment of the lower atmosphere has ceased). While
much of flare research concentrates on the impulsive phase, the gradual phase
is also a topic of hot debate and scientific intrigue as it exhibits some
serious discrepancies between models/theory and observations. Namely, the
modelled cooling times during the gradual phase of flares are significantly
shorter than flare observations suggest. We must ask then, what sustains the
observed gradual phase, and what physical processes are missing from our
models?
It has been suggested that energy release continues in the gradual phase,
with magnitude comparable to that deposited in the impulsive phase. However,
the origin and transport mechanism of this post-impulsive phase energy is
largely unknown. Towards 2050, we must (1) determine the magnitude, source,
and transport mechanisms of energy deposition during the gradual phase; (2)
improve our modelling and observational constraints of the gradual phase, and
our understanding of important plasma physical processes such as turbulence
and non-local effects (which have far reaching effects beyond flares).
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Kerr G. S. Alaoui M. Allred J. C. Bian N. H. Dennis B. R. Emslie A. G. Fletcher L. Guidoni S. Hayes L. A. Holman G. D. Hudson H. S. Karpen J. T. Kowalski A. F. Milligan R. O. Polito V. Qiu J. Ryan D. F.
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Solar Flare Energy Partitioning and Transport — The
Impulsive Phase [#2019]
Solar
flares are a fundamental component of solar eruptive events (SEEs; along with
solar energetic particles, SEPs, and coronal mass ejections, CMEs). Flares
are the first component of the SEE to impact our atmosphere, which can set
the stage for the arrival of the associated SEPs and CME. Magnetic
reconnection drives SEEs by restructuring the solar coronal magnetic field,
liberating a tremendous amount of energy which is partitioned into various
physical manifestations: particle acceleration,
mass and magnetic-field eruption, atmospheric heating, and the subsequent
emission of radiation as solar flares. To explain and ultimately predict
these geoeffective events, the heliophysics community requires a
comprehensive understanding of the processes that transform and distribute
stored magnetic energy into other forms, including the broadband radiative
enhancement that characterises flares. This
abstract discusses energy transport during the impulsive phase of flares.
Our approach to solar flare research from now until 2050 reflects the
following basic philosophy: (1) to identify the sites of energy release and
particle acceleration in the solar corona; (2) to characterize the most
energetically important components as they evolve in time and space; and (3)
to understand how energy is transported and dissipated, heating the Sun’s
atmosphere from photosphere to corona. Observations should be made of these
energy conversion sites before, during, and after the event, to characterize
the magnetic fields, plasma density, temperature, flow velocities, wave
fields, and the accelerated electrons and ions. These properties should be
measured as close to the release site as possible, both in space and in time
to minimize uncertainties due to propagation effects and temporal evolution.
Our aim should be to ensure that models can reproduce fundamental and
universal aspects of flares, and to improve the included physics where they
cannot. We must determine the acceleration mechanism and propagation
properties of accelerated electrons. We must also push beyond the standard
paradigm of energy transport via electron beams, particularly to address the
roles of flare-accelerated ions, and Alfvén waves. To determine whether these
models accurately represent the wide range of flare phenomena, we must confront
them with high-quality observations. We outline key areas where progress
would advance insight into flare physics substantially.
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Klimchuk J. A.
GSFC/ISFM Team on Coronal Heating
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Causes and Consequences of Heating in the
Magnetically Closed Corona [#2136]
Understanding
how the magnetically closed corona is heated and how the plasma responds and
radiates remains one of the most important goals in heliophysics. Determining
what produces the non-uniform thermal structure of the corona is not only
crucial for understanding fundamental physical processes such as magnetic
reconnection, but it is a prerequisite for predicting the variable solar
spectral irradiance, which has major implications for space weather at Earth
and the development of life throughout the cosmos. Finding the necessary
answers is extremely challenging. An enormous range of spatial scales is
involved, and there are close physical couplings among the scales and between
different parts of the solar atmosphere. Progress has been made on isolated
aspects of the problem, but a comprehensive understanding of the
interconnected system is still lacking.
Vital sub-questions that must be addressed include the following. What is the
presently unresolved substructure of the corona and how is it created? What
are the sizes and shapes of elemental magnetic strands? How do they interact
to produce features such as coronal loops? How, when, and where do nanoflares
occur? What is the role of waves – both those generated in the lower
atmosphere and those generated in the corona? How does material cycle between
the corona and lower atmosphere (e.g., chromospheric
evaporation and spicule ejections)? Is thermal nonequilibrium important? What
causes the first ionization potential (FIP) effect? How and why do conditions
vary across and among active regions?
Answering these questions requires a full range of tools: imaging and spectroscopic observations,
numerical simulations, and new theoretical insights. All must be brought to
bear in a coordinated fashion if we are to finally solve the long-standing
mystery of coronal heating and its effects. Our ISFM team at GSFC has made
excellent progress, and we have laid out important pathways
foreword. We look forward to continuing and expanding our engagement with the
broader community.
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Kosovichev A. G. Pipin V. V. Getling A. V.
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Helioseismic Observations of Dynamo Processes in the Solar Interior [#2001]
Helioseismological observations of the internal dynamics of the Sun during the last two
solar activity cycles have made it possible to trace the development of solar
dynamo processes throughout the depth of the convective zone and to link them
with models of solar cycles. Observational data obtained from the GONG
(1995–2020), SoHO (1996–2010), and SDO (2010–2020)
represent measurements of the internal differential rotation, meridional
circulation, and thermodynamic parameters. The structure and dynamics of
zonal plasma flows (torsional oscillations) and variations of the meridional
circulation reveal the processes of generating and transporting magnetic
fields inside the Sun. The observed structure of zonal flows and their
latitudinal and radial migration in deep layers of the convective zone
correspond to dynamo waves predicted by dynamo theories and numerical MHD simulations.
The helioseismic observations and dynamo modeling
provide insight into the extended solar-cycle phenomenon and demonstrate the
potential for advanced prediction of solar cycles. The data reveal
fundamental changes in the solar interior dynamics during the past two cycles
and show the need for future advanced helioseismic observations.
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Leamon R. J. McIntosh S. W.
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Heliospheric Meteorology: HMM, the $200 Mission [#2071]
What?
To make transformational scientific progress with the space weather
enterprise the Sun, Earth, and heliosphere must be studied as a coupled
system, comprehensively. Rapid advances were made in the study, and
forecasting, of terrestrial meteorology half a century ago that accompanied
the dawn of earth observing satellites. Those assets provided a global
perspective on the Earth’s weather systems and the ability to look ahead of
the observer’s local time and move to a global perspective. From a heliospheric,
or space, weather perspective we have the same fundamental limitation as the
terrestrial meteorologists had—by far the majority of
our observing assets are tied to the Sun-Earth line—our planet’s “local time”
with respect to the Sun. This perspective intrinsically limits our ability to
“see what is coming around the solar limb” far less to gain any insight into
the global patterns of solar weather and how they guide weather throughout
the heliosphere. An L5 mission alone is only incremental.
How? We propose a concept—the Heliospheric Meteorology Mission (HMM)—to
sample the complete magnetic and thermodynamic state of the heliosphere
inside 1AU using a distributed network of deep space hardened smallsats that encompass the Sun. The observations and in
situ plasma measurements made by the fleet of HMM smallsats
would be collected and assimilated into current operational space weather
models. Further, the HMM measurements would also being
used in an nationally coordinated research effort—at the frontier of
understanding the coupled heliospheric system—as a means to develop the next
generation models required to provide seamless prediction for the geospace environment to protect vital infrastructure and
human/ robotic explorers throughout the solar system. The HMM mission concept
naturally allows for research-motivated technology development that can
improve forecast skill.HMM is doable with present
technology. Such a mission—in whatever guise or formulation, not necessarily
ours presented here—to observe the entire Sun all of
the time, is critical in terms of scientific understanding of our star and
for the operational need to protect our technologically advancing society.
A Heliospheric Monitoring Mission really is the $200 mission for Heliophysics
in (by) 2050. As in, “Go to HMM. Go directly, do not pass ‘Go’, do not
collect $200.”.
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Lugaz N. Al-Haddad N. Palmerio E. Török T. Farrugia C. J. Jian L. K. Lynch B. J. Winslow R. Manchester W. B. Hess P. Nieves-Chinchilla T. Vourlidas A.
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The Importance of Fundamental Research on the Coronal and Heliospheric
Evolution of Coronal Mass Ejections [#2056]
Coronal
mass ejections (CMEs) are a cornerstone of Heliophysics research. They are
subjects of intense investigation both in the solar and heliospheric domains,
where they constitute the most energetic objects, and in solar
wind-magnetosphere coupling, since CMEs subject the magnetosphere to extreme
and sustained forcing of the magnetosphere. Fundamental research on CMEs
involves their initiation mechanisms at the Sun and the physical processes by
which they couple massive amounts of energy and momentum to magnetospheres
and influence various regions of the magnetosphere-ionosphere-thermosphere
(MIT) system. The 2012 Heliophysics Decadal Survey discusses CME research
associated with their solar origin (SHP3a), their coupling with the MIT
system (Key Science Goal –KSG– 2), and space weather research (KSG 1). Of
particular significance, KSG 4 is related to fundamental processes, but
neither the evolution of low-beta plasmas typical of CMEs nor the
plasma-plasma interaction process, which is central to the formation of CME
sheaths, are mentioned as such fundamental processes. This gap has had
significant implications to the field of CME research in the past decade,
where all investigations of CMEs beyond their initiation are required to loop
back to space weather issues. It is not clear what distinguishes CMEs from
flares or SEPs in this respect, yet the latter two are listed as topics where
fundamental research is required. It is essential to develop a program for
fundamental research on the coronal and interplanetary evolution of CMEs,
independent of their space weather impact. While the ability to approximately
forecast the arrival time and speed of CMEs in operational settings is a
major achievement, there are numerous physical phenomena that operational
codes do not capture: the CME magnetic
field, CME expansion, the turbulent nature of the sheath, substructures
within CMEs, etc. The focus on understanding and forecasting the geo-effects
of CMEs must be grounded in fundamental research. Such research should draw
on investigations focusing on data analysis, theory, numerical simulations,
and code and model development, but also on missions and instruments,
especially in the Explorer and SmallSat categories.
Without such fundamental research on the coronal and heliospheric evolution
of CMEs, we run the danger that, in 2050, we will still be relying on overly
limited models that are based on oversimplified approximations.
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Mason E. I. Higginson A. Weberg M. Rivera Y. J. Spitzer S. A. Alterman B. L.
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The Need for Consistent, Comprehensive Inner
Heliosphere Data [#2011]
The
main science goal presented here is the capability to reliably track individual
packets of solar wind from the low corona to 1 AU by 2050. This capability is
essential for understanding how the Sun generates and accelerates the solar
wind, and how the solar wind impacts the Earth. Better tracing of solar wind
is primarily a logistical matter of providing coverage to best leverage our
current capabilities, rather than a challenge necessitating fundamental
innovations in theory or technology. By utilizing current technologies with
high TRL (satellite constellations and photon sieves), we can produce
powerful new science results. Reliable plasma parcel tracing capability is the means by which the field will achieve further vital
advances in solar theory, solar wind modeling, and space weather forecasting.
In order to accomplish this goal, we need reliable,
high-resolution data measuring solar wind plasma magnetic fields,
composition, particle density, and velocities. These measurements need to
have a cadence on the scale of minutes or better, spaced at regular intervals
encircling the entire Sun, and at regular distances covering out to at least
1 AU. The context provided by universal coverage is critical for researchers
to extract the maximum physical insight from unreplicable
observations such as those from Parker Solar Probe and Solar Orbiter, where
the data results are a relatively small set of very high-quality
measurements. In accordance with our plan, by 2030 there should be data
access to the intermediate Sun-Earth line via an in situ
mission located at L4 or L5, with plans being implemented to expand analogous
coverage around the Sun using a “string of pearls” satellite constellation
with an orbit of roughly 0.5 AU. A constellation of small craft spectrometers
or photon sieves should be planned for 360-degree in-plane solar coverage by
2035. From this enhanced coverage, it will be possible to trace individual
packets of solar wind with a high level of confidence from the corona to 1
AU, placing vital science results within reach for the first time.
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Mason J. P. Chamberlin P. C. Woods T. N. Jones A. Veronig A. M. Dissauer K. Kirk M.
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CME Acceleration as a Probe of the Coronal Magnetic Field [#2003]
Current
state in 2020/2021: It is well
established that the coronal magnetic field is the proximate cause of solar
eruptive events. We have numerous instruments that observe the plasma
emission where the magnetic field strengthens into loops (e.g., EUV and X-ray
imagers). We also have numerous models describing the coronal magnetic field
to varying levels of fidelity (e.g., PFSS, NLFF, MHD). However, there are not
many observations in the “middle corona” (here defined ~1.5–5 Rs), which
means a lack of strong constraints for those modeled field topologies and
dynamics. This is precisely the region where CMEs experience the bulk of
their acceleration, and their kinematic profiles are directly influenced by
the background magnetic field they pass through.
The desired state by 2050: CME models accurately describe — and
ideally predict — observed solar eruptions and the propagation of CMEs
through the corona. This state implies that we will have obtained a deep
understanding of the coronal magnetic field.
The journey: We must address known unknowns and be
prepared for unknown unknowns.
Known unknowns: Expand observational regimes, e.g., direct
coronal magnetic field observations, multiple observational angles to observe
the sun as a 3D object, observe the middle corona. Also improve upon existing
CME models, e.g., more complete treatment of fundamental plasma processes,
incorporation of new observational constraints, linking magnetic field lines
from photosphere to source surface, and achieving consistency among multiple model runs in solar max regime.
Preparation for unknown
unknowns: Expand the community, e.g.,
collaborate with astronomers on sun-like star observations. Also make
powerful tools easy to use and big data easy to access and manipulate for
non-experts in heliophysics or in computer science, e.g.,
machine learning.
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Newmark J. Hassler D. Gibson S. Vial N. Hoeksema T. Vourlidas A.
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Solar Heliosphere Constellation [#2031]
Our
current understanding of the Sun, its atmosphere, and how it creates the
heliosphere is severely limited by the lack of nearly ANY observations of the
polar regions. Opportunities for discoveries abound for spacecraft out of the
ecliptic plane, as new vantage points inevitably lead to discoveries and
insight. Multiple fundamental problems will be addressed, including the solar
dynamo, the origins of coronal mass ejections, the polar magnetic fields, and
the formation of the solar wind. Establishing 4π coverage of the Sun and
inner heliosphere is the obvious next step for full understanding of the
global, time-dependent heliosphere. Only high latitude (>55°) and full
360° longitude observations can lead to fundamental, PSP-grade, leaps in
Heliophysics and Space Weather understanding. Long duration, high latitude,
near-continuous observations are required to extract information about the
(deep-seated) flows in the vicinity of 55° (or above). Long orbital periods
are required to keep relevant latitudes in the field of view as continuously
as possible.
In addition to the discoveries expected with a polar view of the Sun,
improving space-weather forecasts requires observations from off the
Sun-Earth line and in particular, observations from the solar poles. The
longitudinal “sunny-side-up” coverage from a spacecraft positioned near the
solar rotation axis is particularly useful, uniquely providing space weather
monitoring for all the planets and spacecraft in the inner heliosphere, not
just the Earth-Moon system and L1. This will become increasingly important as
human exploration takes us out into the heliosphere.
These science questions and space weather requirements lend themselves
naturally to a disaggregated constellation, meaning one made of various
differing Observatory concepts. We present 3 case studies, Solaris, Solar
Polar Explorer (SOLPEX), and Inner Heliosphere Sentinels (IHS) that
demonstrate this. The Solaris mission, currently undergoing Phase A study,
will be a pathfinder for discovery, imaging the Sun’s poles from
heliolatitudes >70° for months at a time. SOLPEX is similar in mission
design to Solaris, but has a significantly larger
instrument complement and adds solar electric propulsion to enable multiple
passes over both solar poles. The IHS is a concept for a constellation of
sub-L1 smallsats, using solar sails derived from
the technology being developed for the Solar Cruiser mission, currently under development.
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Oka M.
Glesener L. Caspi A. Narukage N.
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Solar Flares as the Key Toward Understanding Particle Acceleration in
the Plasma Universe [#2092]
Particles
are accelerated to very high, non-thermal energies during explosive
energy-release phenomena in space, solar, and astrophysical plasma
environments (or the Plasma Universe). However, how particles are accelerated
in these plasma environments remains unclear. In this regard, solar
remote-sensing observation is special in a sense that, unlike in-situ
measurements of Earth’s magnetosphere, it provides large-scale contexts of
particle acceleration through imaging, and yet it still resolves their
spatial and temporal structures in much more detail than flux-limited
observations of distant astrophysical objects. The possible structures that
need to be resolved to understand the context of particle acceleration
includes, but not limited to, shocks, waves/turbulence, plasmoids,
jets, current sheets, and collapsing loops. In fact, a variety of different
theories of flare particle acceleration has been proposed using one or more
of these structures. However, previous observations have been unable to
constrain the model due partly to insufficient measurement in soft X-rays
(SXR) which is suitable for diagnosing (super) hot plasma and hence the
context of particle acceleration. In general, soft X-ray (or bremsstrahlung
continuum) photons are emitted directly and instantly from energized
electrons interacting with (or deflected by) ions, with no non-equilibrium
delay. With imaging-spectroscopy in both soft and hard X-rays, the transition
from thermal to non-thermal energy ranges will be covered seamlessly. In
fact, such a measurement is under development in future mission concepts such
as PhoENiX and CubIXSS.
In this presentation, we argue that future studies of solar flare particle
acceleration with imaging-spectroscopy in soft and hard X-rays would
facilitate comparative studies of particle acceleration in various plasma
environments and exploration of possible scaling-laws as well as
their universality.
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Parker L. N. Minow J. I. Pulkkinen A. St.Cyr O. C. Jun I. Semones E. Onsager T. Hock R. Mertens C. Allen J. Fry D.
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Space Weather Architectures for
NASA Missions [#2017]
Since
the final human Moon landing in 1972, all human space exploration has taken
place in low-inclination low Earth orbit (LEO), where the Earth’s
magnetosphere provides relative protection from harmful space radiation. In the near future, as humans return to the Moon, existing
scientific and operational ground- and space-based assets should provide
sufficient warning of sporadic eruptions from the Sun. Journeys beyond
cislunar space, however, will require new monitoring infrastructure and
operational procedures to protect astronauts from space radiation hazards.
Therefore, infrastructure supporting cislunar space operations can serve as a
testbed for these future needs.
A NASA Engineering and Safety Center (NESC) assessment team evaluated the
required minimum latency for data streams and forecasts that will directly
affect mission operations using the European Space Agency’s Solar Energetic
Particle (SEP) Environment Modeling RSDv2.0 41-year database of SEP events.
The database contained 192 SEP events that resulted in a dose increase above
background levels. Of those, 10% were “multiple events,” or events that
occurred in quick succession. The analysis provides probabilistic values for
time to peak flux and dose rate for the duration of each event. This NESC
assessment also evaluated the SEP threshold levels for exploration missions
to determine the relevant energy range of required proton measurements.
Accurate modeling and prediction of SEPs is a major challenge, and the
performance of available models leaves room for improvement. However,
promising paths for predictive SEP modeling have been identified and are
actively being explored by the space weather community.
Operational timeline requirements were developed to ensure general mission
planning and situational awareness for lunar and Mars missions. Various
architectures were developed for lunar and Mars missions, providing different
cost categories in the form of instrument packages of increasing ability
(i.e., baseline, enhanced, and comprehensive). Finally, the assessment
provides a research and development strategy to bridge the time from
successful lunar missions to Mars missions. We will provide an overview of
the analysis and recommendations for future NASA space
weather architectures.
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Peretz E. P. John Mather J. M. Douglas Rabin D. R. Jeff Kuhn J. K. Thomas Rimmele T. R. Dirk Schmidt D. S.
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Observing Coronal Microscales from the Ground Using an Orbiting
Artificial Guide Star and Adaptive Optics [#2049]
Why the
Sun has a tenuous upper atmosphere some 1000 times hotter than the
photosphere is a fundamental open problem in space plasma physics despite
decades of study. Observations by soft x-ray (SXR) and extreme ultraviolet
(EUV) imagers have provided important clues regarding the nature of the
heating, but the structure of the heated regions remains cloaked, and the
heating mechanisms remain unknown. The primary hypothesis is that, in most of
the corona, heating is confined to narrow current sheets in which energy is
dissipated despite the low large-scale resistivity of the coronal plasma. The
characteristic scale of these current sheets is estimated to be on the order
of 100 km (0.14 arcsec) or smaller.
High-temperature (> 5 MK)
coronal plasma can only be isolated with space-based SXR and EUV instruments,
but coronal electron density and 1–2 MK plasma can be studied from the ground
with high angular resolution using a coronagraphic telescope equipped with
adaptive optics. The corona is much fainter than the daytime sky and cannot
be used as the target of a conventional solar adaptive optics system. Only
one bright (first magnitude) star comes marginally near enough to the Sun,
one day a year. Artificial guide stars created by ground-based lasers do not
work well at visible wavelengths. A hybrid ground- and space-based solution
is found in the proposed ORCAS (Orbiting Configurable Artificial Star)
mission concept. ORCAS could provide a magnitude zero (or brighter)
artificial star (laser beacon) superposed on the low solar corona (<2 Rsun) for an hour or more every 3-5 days during an
observing campaign. The adaptive optics system of the 4-m Daniel K. Inouye
Solar Telescope (DKIST) is capable of tracking this
beacon and acquiring nearly diffraction-limited images with a resolution of
approximately 0.04 arcsec in the white-light (electron scattering) corona or
the 2 MK emission line of Fe XIV.
In the baseline mission concept,
the ESPA-Grande class ORCAS satellite is stationed in a highly elliptical
Earth orbit, which can be chosen to provide a desired angular velocity
relative to the Sun or to passively keep a specified solar location within
the isoplanatic patch for up to 3 hours at the
location of DKIST. Alternatively, a laser beacon orbiting the Sun-Earth L1
Lagrange point could support a continuous observation throughout the life of
the satellite but would require a higher laser power or better
beam focusing.
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Plowman J. E.
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Implications of a New Capability for 3D Coronal
Reconstruction from a Single Perspective Snapshot [#2141]
I
demonstrate how a three-dimensional picture of coronal plasma structures can
be constructed using a photospheric magnetogram and
optically thin EUV observations, even with a single perspective snapshot.
Moreover, I argue that the residuals from this picture can then be used to
determine the coronal magnetic field. In addition to representing a viable
way forward in tackling this critical data analysis problem, this new
technique allows benchmarking which observables are necessary to obtain the
3-dimensional picture, and allows us to obtain more
from the same data. E.g., rather than needing an entire constellation of
spacecraft filling the ecliptic (or above), the results suggest we only need
a handful (with some useful results possible with just one perspective). They
also indicate essential capabilities for this task, namely photospheric magnetography and
optically thin coronal observations with broad temperature coverage (roughly
0.3 to 10 MK). This can be accomplished with 4 to 6 EUV channels (similar to AIA), but might also be accomplished with a
pair of soft X-Ray channels — the soft X-ray temperature response functions
are naturally suited to the analysis.
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Posner A. Arge C. N. Staub J. StCyr O. C. Folta D. Solanki S. K. Strauss R. D. T. Effenberger F. Gandorfer A. Heber B. Henney C. J. Hirzberger J. Jones S. I. Kuehl P. Malandraki O.
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A Multi-Purpose Heliophysics L4 Mission [#2023]
The
solar radiation hemisphere (SRH), which coincides with the hemisphere in view
from L4, is the source of all potentially hazardous solar energetic particle
events at Earth. L4 and existing assets at Earth would establish continuous,
detailed surveillance of active regions of 2/3 of a solar rotation. L1/L4
combined assets would provide for the reduction of ambiguity in the
observation of solar magnetic fields through Zeeman polarimetry. Two
magnetographs when placed 60° apart would resolve the inherent ambiguity in
azimuthal magnetic field components applying to quiet background fields, but
also to active regions that rotate into the solar radiation hemisphere. The
added knowledge of vector magnetic fields combined with growing machine
learning and AI technology could lead to breakthroughs in solar activity
forecasting and understanding. Mars explorers on their journeys to and from
Mars, would be particularly vulnerable to SEPs. On fast journeys to Mars,
which would reduce exposure to cosmic rays considerably, explorers would be
magnetically connected to regions behind the solar W limb as viewed from
Earth, but well within view from L4. This along with the expanded longitude
coverage that L4 provides for solar observations during astronauts’ stay at
Mars, would make an L4 mission a vital part of human Mars exploration plans
in the 2030s and beyond. L4, L1 and L5 observations would boost scientific
understanding of inner-heliosphere solar wind structure, vital for our
ability to predict the most severe geomagnetic storms at Earth. At current,
coronal and solar wind models use diachronic maps, i.e.
not all regions of the Sun are observed simultaneously but recorded over
time. L4 and L5 missions would reduce the wait time for a complete map to ~12
days, drastically improving inner heliosphere solar wind modeling. Flux
emergence could be constrained further, even on the Sun’s far side, through helioseismic holography. Moreover, L4 offers another
platform for viewing the entire Sun-Earth line with coronographic and
heliospheric imaging technology, but well out of the way of the associated
SEPs that are associated with the Earth-directed CME. Inclined L4 and L5
orbits would ideally cover solar poles and low-latitude solar wind structure,
further enabling modeling and model verification of inner-heliosphere solar
wind structure, and laying the groundwork for a space
weather architecture in the 2050s.
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Prete G. Perri S. Zimbardo G.
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Energetic Particle Fluxes at Heliospheric
Shocks: Evidence of Superdiffusion and Comparison Between Analytical and
Numerical Modeling [#2102]
Energetic
particle fluxes measured by spacecraft in the heliosphere are frequently
observed to peak during interplanetary shock crossings, suggesting the shock
to be the source of acceleration. Energetic particle transport properties can
affect the shape of energetic particle fluxes, in both sides of the shock
region. In this study, we make a comparison among some shock crossings
observed by the ACE spacecraft, and the energetic particle fluxes derived by
a test-particle numerical model in the vicinity of a planar shock. We find
that observations are in good agreement with a particle density profile
obtained in the simulation by assuming superdiffusive
transport both upstream and downstream of the shock region.
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Rabin D. M. Daw A. N. Denis K. L. Klimchuk J. A. Kamalabadi F. Schmit D. J. Golub L. Novo-Gradac A.-M.
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Probing Corona Microscales [#2047]
After
decades of study, we still don’t know why the Sun
has a tenuous upper atmosphere some 100-1000 times hotter than the
photosphere. Soft x-ray (SXR) and extreme ultraviolet (EUV) imaging and
spectroscopy have provided important clues to the nature of the heating,
particularly in magnetically closed regions, but the spatial structure of the
heated regions and the interplay between magnetic reconnection and wave
heating are largely unknown. The leading hypothesis is that heating is
confined to narrow layers or small regions in which energy can dissipate
despite the low resistivity and viscosity of most of the coronal plasma. The
characteristic scale of these structures is typically estimated to be
<~100 km (0.14 arcsec). The overarching scientific goal of studying
coronal microscales over the next three decades should be a quantitative
understanding of the structure and mechanisms of coronal heating on the
physical scales predicted by contemporary (and evolving) theories.
Quantitative understanding will entail comparing observations of
unprecedented angular resolution with numerical simulations that have enough
physical realism and few enough free parameters that some models can be ruled
out for a specific set of observations, and at least one model agrees well. A
major advance in angular resolution over a range of temperatures will
undoubtedly require and stimulate new theory and more powerful simulation.
At least three observational approaches to probing coronal microscales merit
discussion and development. All approaches require a long effective focal
length to produce a large image scale.
(1) Diffractive optics are thin, light, flat, and obtain nearly diffraction-limited EUV/SXR images with greatly relaxed
surface accuracy compared to mirror optics. Their intrinsically long focal
lengths at short wavelengths require a distributed formation-flying
telescope. A two-CubeSat EUV telescope using a photon sieve is expected to be
demonstrated by 2024.
(2) Because of recent advances in figuring and polishing aspheric mirrors to
sub-nanometer accuracy and smoothness, an all-reflecting, diffraction-limited
EUV telescope accommodated on a single spacecraft is likely feasible now or
in the near future.
(3) A laser beacon carried on a small satellite can provide an artificial
guide star that could be used by large ground-based telescopes in conjunction
with adaptive optics to obtain nearly diffraction-limited images at
visible/near-infrared wavelengths.
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Reardon K. Cauzzi G. Rimmele T. Schad T. Tarr L. Tremblay B. Rast M.
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Revealing Fundamental Physics of the Sun
with DKIST [#2128]
The
Sun’s atmosphere represents a unique testbed for deciphering fundamental
plasma processes in regimes not accessible by laboratory experiments, as well
as a resolvable template relevant to a range of astrophysical phenomena. Our
understanding of this system depends on an integrative, data-driven approach
that necessarily intertwines the interpretive power of state-of-the-art
numerical simulations and the physical touchstone of cutting-edge, highly-resolved solar observations. The desired goal is a
deep knowledge of how the solar atmosphere behaves across a range of temporal
and spatial scales, and the ability to make projections about its dynamic
behavior. From a broader perspective, this knowledge will inform on very
general phenomena such as magnetic reconnection, shocks, turbulence,
multi-species plasmas, and, crucially, their interconnections.
The 4-meter-diameter Daniel K. Inouye Solar Telescope (DKIST; Rimmele et al., 2020), funded by the National Science
Foundation (NSF), will play a fundamental role in these efforts. It has been
designed to provide information on crucial, and yet poorly known, physical
properties of the solar atmosphere such as the chromospheric
and coronal magnetic fields. DKIST’s early science goals, summarized in the
Critical Science Plan [Rast et al., 2020], are rich
and far reaching, with significant discovery science. Planned to be a responsive
facility during its lifetime, DKIST will evolve as scientific questions and
available technologies advance. It is anticipated to remain at the forefront
of ground-based observational solar physics for the next three decades? and
will be essential to achieving a comprehensive view of the solar atmosphere.
It will also be an integral partner with space-based missions in
multi-messenger heliophysics, enabling a holistic understanding of the
heliosphere [Martinez Pillet et al., 2020].
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Rivera Y. J. Higginson A. Lepri S. T. Viall N. Alterman B. L. Landi E. Spitzer S. A. Raines J. M. Cranmer S. R.
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Connecting Heliospheric Phenomena with Their Solar Source Through
Multi-Point Compositional Measurements [#2159]
Spacecraft
have long measured solar plasma on a multitude of spatial and temporal scales
at several locations around our solar system, both remotely and in situ. Yet,
we still lack a fundamental understanding of how energy and mass is
transferred between the Sun and interplanetary space, because it is not
currently possible to track plasma from the Sun’s chromosphere through the
corona into the heliosphere. Our understanding of the physics that drives the
release, heating, and acceleration of the solar wind and transients is still
incomplete. These parameters are crucial to understanding the Sun and its
impact on Earth and the rest of the heliosphere. To fully address these
questions, it is critical that we understand the evolution of the plasma as
it leaves the Sun and fills the heliosphere. As such, we must meaningfully
and quantifiably connect and compare remote and in situ plasma measurements.
It is well known that elemental and ion composition hold important clues for
linking the solar-heliospheric environment, as well as for deciphering the
energization of the solar wind. This is due to the wealth of information that
charge states can provide about the origin and thermodynamic evolution of the
plasma. In addition, the kinetic properties of heavy ions can provide a unique
window to non-thermal signatures imprinted by heating and acceleration
mechanism(s) in their velocity distribution functions from in situ
measurements and spectral profiles of plasma lifting off from the Sun.
Combined, ion and elemental composition can trace individual solar wind
parcels to specific source regions, and provide
insight to the global picture of solar wind release, heating, and
acceleration.
Current missions target measurements of young solar wind but, generally, in
situ and remote instruments are not integrated in a manner that provides the
continuous multi-point ion measurements necessary to fully address these
questions by coupling in situ and remote observations. This poster discusses
two overarching goals for effectively bridging solar-heliospheric phenomena
by 2050: (1)
continuous 4π Sun coverage of compositional measurements in situ and
remotely, and (2) the development of cohesively designed and improved
alignment of compositional properties observed with both in situ and remote
observation instruments. Goal (1) allows us to trace the evolution of plasma
between the Sun and heliosphere. Goal (2) will drive the design of
instruments necessary to meaningful compare composition throughout the solar
wind evolution. Through this global solar view, we can build a more
comprehensive description of the solar wind and transients, and potentially
solve some of the largest open questions in heliophysics.
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Ryan J. M. de Nolfo G. A. MacKinnon A. McConnell M. L. Murphy R. Vilmer N. Young C. A.
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High-Energy Neutrons in the Heliosphere [#2162]
We
outline the value of performing low background, spectroscopic measurements of
fast neutrons to advance the science of solar energetic particles, the inner
radiation belt proton budget, and lunar and planetary regolith composition.
With the existing rarity of such measurements, breakthroughs are likely in
understanding Long Duration Gamma Ray Flares, accelerated solar proton
spectra, time-resolved proton injection into the inner belts, and average Z
measurements of lunar planetary surfaces.
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Samra J. Cheimets P. DeLuca E. Del Zanna G. Golub L. Judge P. Kramar M. Lin H. Madsen C. Marquez V. Testa P. Tomczyk S.
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A Balloon-Borne Infrared Coronagraph and Spectropolarimeter for Magnetic
Field Measurements of the Solar Corona [#2115]
We
present a balloon-borne infrared coronagraph and spectropolarimeter for
long-duration measurements of coronal plasma and magnetic fields. The Coronal Spectropolarimeter for Airborne Infrared Research (CORSAIR,
selected Feb. 2021), will yield major advances in our understanding of
the inner corona while serving as a prototype for future space
instrumentation. CORSAIR will observe five emission lines at 1.1, 1.4, and
3.9 μm, including a density-sensitive Fe XIII
line pair, a temperature-sensitive Si IX/X line pair, and a He I line for probing cooler plasma. The instrument will
measure the corona’s full polarization state integrated along the line of
sight (LOS), providing estimates of LOS magnetic field strength, plane-of-sky
(POS) field direction, and plasma thermodynamics under the assumption that
emission is restricted to the POS. During a future long-duration observation,
tomographic inversions will yield the three-dimensional vector magnetic field
as well as plasma temperature and density. Our primary science goals explore
the transition of coronal structures between closed and open field and the
role of waves and flows in transporting mass and energy in coronal magnetic
fields.
CORSAIR is a coronagraph, polarimeter, and grating spectrometer that provides
two-dimensional spectropolarimetric imaging up to
one solar radius from the limb. The spectrometer includes up to 128 slits,
which enable the spectral dimension and the 1x1 degree spatial field of view
to be acquired simultaneously. By operating in multiple orders, the
polarimeter and spectrometer measure each of the five emission lines with
similar sensitivity and resolution. CORSAIR will be developed by Smithsonian
Astrophysical Observatory in collaboration with the NCAR High Altitude
Observatory and the University of Hawaii Institute for Astronomy. A one-day
commissioning flight in September 2024 will be followed by a long-duration
Antarctic flight in late 2026 or 2027.
The storage of magnetic free energy
in coronal structures has been recognized for decades, and the build-up of
energy over long time scales and its rapid release in the form of flares and
CMEs are defining characteristics of activity on the sun and sun-like stars.
The prospect of following the global coronal magnetic field evolution
continuously over time scales from tens of hours to weeks holds great promise
for advancing our understanding of coronal energy storage and the onset of
instabilities that result in energy release.
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Seaton D. B. West M. J. Alzate N. Caspi A. DeForest C. E. Gilly C. Golub L. Higginson A. K. Kooi J. E. Mason J. P. Rachmeler L. A. Reeves K. K. Savage S. Viall N. M. Wexler D. B.
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A Strategy for a Coherent and Comprehensive
Basis for Understanding the Middle Corona [#2069]
The
Middle Corona – the region between typical active region loop
tops and the apex of dynamic streamer cusps, extending roughly from 1.5 to 6
solar radii – encompasses nearly all physical transitions and processes that
govern the behavior of coronal outflow, both steady and in transient events.
Importantly, it also modulates inflow from above that can drive dynamic
changes at low heights, and is the location of many
disconnection events that contribute to the solar dynamically-open flux
budget. Consequently, this region is essential for understanding the physics
of the corona, the heliosphere, and the eruptions that propagate through
them. Because it is challenging to observe, the middle corona has been
somewhat overlooked by major solar missions and instruments going back to the
SOHO era. To address this discrepancy, a strategy of well-coordinated
instrumentation is required to produce continuous and overlapping coverage of
the whole corona over the full range of observational regimes (e.g. X-Ray, EUV, Visible, IR, etc.) needed for global
models and studies that can characterize, interpret, and ultimately
understand the physical processes that govern this region. Additionally,
radio remote sensing techniques, such as Faraday rotation, measurements of gyrosynchroton emission, etc., can probe magnetic field
intensities and electron densities, presenting significant opportunities if
synchronized with imaging observations, models, and new instrumentation
investments. Moreover, multi-perspective observations are required to
determine the three-dimensional structure of the complex interfaces between
the low corona and outer corona/heliosphere that bound this region. Relating
three-dimensional structure and magnetic field observations to global coronal
models is essential for understanding this system as a
whole, so obtaining the 360°/4π views of the photospheric
magnetic field, which these models require as a boundary condition, is a
critical need. Here, we discuss the need for strategic planning for
continuous, coherent, and comprehensive observations of the middle corona and
outline a plan to achieve such observations in the coming decades.
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Shih A. Y. Glesener L. Krucker S. Guidoni S. Christe S. Reeves K. Gburek S. Caspi A. Alaoui M. Allred J. Battaglia M. Baumgartner W. Dennis B. Drake J. Goetz K. Golub L. Hannah I. Hayes L. Holman G. Inglis A. Ireland J. Kerr G. Klimchuk J. McKenzie D. Moore C. Musset S. Reep J. Ryan D. Saint-Hilaire P. Savage S. Schwartz R. Seaton D. Stęśicki M. Woods T.
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Fundamentals of Impulsive Energy Release in the Corona [#2091]
Solar
eruptive events are the most energetic and geo-effective space-weather
drivers. Many of the processes involved in triggering, driving, and
sustaining solar eruptive events — including magnetic reconnection, particle
acceleration, plasma heating, and energy transport in magnetized plasmas —
also play important roles in phenomena throughout the Universe. We discuss
areas of science investigation that would significantly advance our
understanding of these fundamental physical processes.
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Shih A. Y. Vilmer N. MacKinnon A. Pesce-Rollins M. Vainio R. Hudson H. Simões P. J. A. Cohen C. M. S.
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Ion Acceleration in Solar Eruptive Events [#2090]
Observations
of energetic ions in solar eruptive events — solar flares with associated
CMEs — are critical to understanding the transient, efficient release of
stored magnetic energy at the Sun. Solar flares are the most powerful
explosions in the solar system, efficiently accelerating ions up to tens of
GeV. CME-driven shocks also accelerate ions to extreme energies in SEP
events. Observing ion signatures is necessary to answer open questions
regarding ion acceleration and transport.
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Sorriso-Valvo L. Carbone V. Khotyaintsev Yu. V. Steinvall K. Telloni D. Yordanova E.
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Statistical Study of Electron Density Turbulence and Ion-Cyclotron
Waves in the Inner Heliosphere: Solar
Orbiter Observations [#2099]
The
recently released spacecraft potential measured by the RPW instrument
on-board Solar Orbiter has been used to estimate the solar wind electron
density in the inner heliosphere.
Solar-wind electron density measured during June 2020 has been analyzed to
obtain a thorough characterization of the turbulence and intermittency
properties of the fluctuations. Magnetic field data have been used to
describe the presence of ion-scale waves.
Selected intervals have been extracted to study and quantify the properties
of turbulence. The Empirical Mode Decomposition has been used to obtain the
generalized marginal Hilbert spectrum, equivalent to the structure functions
analysis, and additionally reducing issues typical of non-stationary, short
time series. The presence of waves was quantitatively determined introducing
a parameter describing the time-dependent, frequency-filtered wave power.
A well defined inertial range with power-law
scaling has been found almost everywhere. However, the Kolmogorov scaling and
the typical intermittency effects are only present in part of the samples.
Other intervals have shallower spectra and more irregular intermittency, not
described by models of turbulence. These are observed predominantly during
intervals of enhanced ion frequency wave activity. Comparisons with
compressible magnetic field intermittency (from the MAG instrument) and with
an estimate of the solar wind velocity (using electric and magnetic field)
are also provided to give general context and help determine the cause for
the anomalous fluctuations.
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Sterling A. C. Moore R. L. Panesar N. K. Samanta T.
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Solar Coronal Jet Studies as an Example that
Motivates Future High-Resolution Solar Investigations [#2163]
Many of
the key advances in solar science over the previous fifty years have been
strongly influenced by imaging with increasing resolution and cadence of
the Sun’s atmosphere from space. There is still much room for further
advances in this area in the coming decades. Here we demonstrate this need
using as an example recent past advances of the features known as solar
coronal jets. Over the last few decades jet studies have progressed
substantially, and much of this is due to improved resolution and
cadence in imaging, along with concurrent magnetic field and
spectroscopic studies. We now understand that the jets apparently
are caused by solar eruptions of a smaller scale than, but otherwise
essentially identical to, those that make solar flares and CMEs. Thus the high-resolution studies of coronal
jets potentially informs us on how the larger eruptions work. In
addition, coronal jets in the feet of open magnetic field might inject
magnetic twist pulses that become the switchbacks discovered by the Parker
Solar Probe in the magnetic field in the inner solar wind. Future
higher-resolution, higher-cadence studies of solar features and events, at a
variety of wavelengths, along with magnetic field information (such as
magnetograms) of comparable resolution and cadence, will, for the foreseeable
future, advance our understanding of the preparation and production of solar
eruptions of all sizes, their role in heating the chromosphere and corona,
and how they drive, perturb, and disrupt the solar wind.
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Swisdak M. Antiochos S. Qiu J. Glesener L. Dahlin J. Klimchuk J. SolFER Collaboration
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Solar Flare Onset and Dynamics [#2110]
The
mechanism(s) responsible for the explosive release of magnetic energy in
X-class flares and fast CMEs occupy a central role in heliophysics.
Especially challenging to our understanding is the amazing rate of energy
release, over 1032 ergs on time scales of minutes. Not only are
flares/CMEs the primary drivers of the most destructive space weather, but
they also offer an opportunity to study fundamental processes such as MHD
instabilities, magnetic reconnection, particle acceleration, and shock
formation that lie at the heart of explosive activity throughout the cosmos.
In recent decades major progress on this problem has come from the synthesis
of space observations, advances in basic theory, and breakthroughs in
numerical modeling. It is now accepted that the free energy is stored in a
filament channel overlying a polarity inversion line, while the possible
mechanisms for creating these structures has been narrowed to three: flux emergence, flux cancellation, and
helicity condensation/shear flows. Furthermore, the disruption of the
pre-flare equilibrium and initiation of the energy release occurs in one of
two ways: through ideal instabilities, such as kink or torus, or reconnection
instabilities, such as breakout or tether-cutting.
Irrespective of the mechanism, observations and theory/modeling have clearly
established that flare reconnection is the dominant energy release process,
although important questions remain regarding its rate and dynamics.
In coming decades NASA Heliophysics must not merely determine which of these
mechanisms dominates, but must also achieve a
sufficiently deep understanding that accurate first-principles-based
predictions of flares and their space weather impact become possible. There
are three hurdles to attaining this grand challenge goal. First, we need new
high-resolution observations of the energy release process. New instruments
and missions should be able to deliver these observations. Second, we must
develop new insights into the MHD-kinetic-scale coupling at the heart of
reconnection and the flare phenomenon. Finally, we must develop numerical
models of the full 3D energy buildup and release process to achieve closure
with the new observations.
In this iPoster we present the latest advances on the latter two issues from
the NASA DRIVE science center on Solar Flare Energy Release (SolFER) that has brought together theorists, modelers,
and observers to attack these challenges.
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Szabo A. Bale S. Kasper J. C. Ho G. Raouafi N. E.
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Inner Heliospheric Flotilla [#2029]
A nine
spacecraft, inner heliospheric mission concept is presented to address the
following outstanding science objectives:
1: Determine the internal topology and evolution of ICMEs as to travel
from the Sun to 1 AU; 2: Determine the longitudinal extent and diffusion of
energetic particle particle beams; 3: Determine the
global structure of the inner heliosphere as a function of solar drivers. In
addition, this mission could provide 1–2 day
forecasts of solar transients at Earth or at any other location in the
ecliptic. All small spacecraft would carry fields and particles in-situ
instrumentation and one of three solar remote sensing telescopes (EUV imager,
coronagraph, and magnetograph). In their 0.5 x 0.76 AU orbits, the nine
spacecraft will change their configuration from tight formations for ICME and
transient studies to fully distributed around the Sun to study the global
structure of the heliosphere. A single launch vehicle could deliver all nine
spacecraft to their orbits.
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Tiwari S. K. Thalmann J. K. Panesar N. K. Evans C. L. Prasad A. Moore R. L. Winebarger A. R. DeRosa M. L.
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Dependence of the Heating in Active Region Coronal Loops on Magnetic
Conditions at the Loop Feet in the Photosphere [#2074]
Using
SDO/AIA and SDO/HMI data and coronal magnetic field modeling of solar active
regions (ARs), we find that freedom of convection and strength of magnetic
field in the photospheric feet of AR coronal loops,
together, can engender or quench heating in them. From EUV observations and
non-linear force-free field modelling it is shown that the hottest loops of
ARs are the ones connecting sunspot umbra/penumbra at one end to (a)
penumbra, (b) unipolar plage, or (c) mixed-polarity
plage on the other end. The loops connecting dark
sunspot umbra at both ends are not visible in EUV images - thus, these loops
are the coolest loops. Some recent investigations stress more on the
loop-foot mixed-polarity (above-mentioned connectivity ‘c’), suggesting that
flux cancellation might be the dominant mechanism in heating chromospheric and coronal loops, as well as in driving
fine-scale explosive events, e.g., seen by Hi-C 2.1. In this presentation, we
will show some latest results and challenges posed to understanding the
dependence of heating in AR coronal loops on the distribution and evolution
(including cancellation) of magnetic flux at the loop feet. Further, to
address the challenges posed, we will argue for the need of much higher
spatial and spectral resolution magnetograms than SDO/HMI, of a large field of
view (e.g., for following both ends of AR loops for hours to days),
preferably full-disk Sun. Continuous Hi-C like observations of
finely-structured corona in EUV, together with super-HMI-like magnetograms
(with a spatial resolution of Hinode/ SOT-SP or better),
will also help understanding the fine-scale explosions reported from using
5-minute observations of Hi-C 2.1.
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Velli M. Panasenco O. Artemyev A. Runov A. Tripathi S. Lin Y. Nishimura T. Riley P. Egedal J. Abbett W. Lynch B. Tenerani A. Gonzales C. Downs C. Titov S. Shi C. Sioulas N. Lu S. Reville V. Innocenti M. E. Zimovets I. McAteer J.
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HERMES: HEliospheRic Magnetic Energy Storage and Conversion: From the Solar Corona to
Planetary Magnetospheres [#2148]
The
HERMES (HeliospheRic Magnetic Energy Storage and
conversion) DRIVE Science Center will provide a community framework for
studying the basic mechanisms of energy storage and release in the natural
plasmas of the heliosphere. In this poster we present HERMES research
programs to understand magnetic energy storage and release in the solar
corona and inner heliosphere, from coronal heating
mechanisms, to filament channel development and destabilization, to
the development of the heliospheric current sheet and the role of Alfvénic turbulence in the nascent solar wind. We will
also describe how synergies and comparisons with energization at the Earth’s
magnetosphere, via the solar wind-magnetosphere interactions, and phenomena
such as flux transfer events, reconnection in the tail, turbulence and dipolarization fronts, as well as interactions with the
ionosphere, will help to progress fundamental understanding of natural
plasmas. In addition, plasma experiments to validate or disprove theories and
models are planned within the Science Center environment. These advances will
lead to a discussion of necessary future developments in solar atmospheric
observations of the Sun, exploration of the in situ solar wind and the
magnetospheres of other planets, as well as to discussions of the development
of plasma modeling and novel numerical simulation experiments over the coming
decades.
Acknowledgement: This work was
supported by the NASA HERMES DRIVE Science Center grant
No. 80NSSC20K0604.
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Wexler D. B. Efimov A. I.
Jensen E. A. Vierinen J. Coster A. Lukanina L. Song P.
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Solar Wind Acceleration Through the Middle Corona: Spacecraft Radio Studies [#2055]
The
designation “Middle Corona” is a presently an operational term that refers
roughly to the region 1.5–6 solar radii (Rs, heliocentric) through which
several important structural and dynamic changes occur in coronal streamer
regions. Among these is a regime change from high density, closed magnetic
field structures to open field structures of much lower electron
concentration. Along with this complex restructuring, the forming slow solar
wind is channeled and accelerated through the middle corona. Studied in
trans-coronal radio sensing methods, solar wind outflow speeds can be
estimated from observations of radio signal amplitude scintillations and by
analysis of the frequency fluctuations (FF). Trans-coronal radio studies of
the middle-corona, using observations from HELIOS (S-band), MESSENGER
(X-band) and Akatsuki (X-band) spacecraft radio transmissions were
undertaken. The radio FF analysis treats the frequency fluctuations as
speed-dependent density inhomogeneities crossing the sensing line-of-sight
(LOS). With suitable model parameters such as the correlation scale and the
fractional amplitude of the density disturbances, the implied speeds can be
calculated. We found that below 2 Rs, where the SW is beginning to form and
outflow speed expected to be well below the acoustic wave speed, the radio FF
could be attributed to the density oscillations of acoustic waves crossing
the radio sensing path, such that the RMS fluctuation levels trended with the
steep curve of modeled underlying plasma electron density. In contrast, with
increasing helioaltitudes through the middle
corona, the RMS FF radial dependence shifted to a mass flux power law,
consistent with density disturbances advected across the sensing LOS. We
determined a solar wind acceleration curve and compared this to other wind
speed estimates from the literature. The solar wind coronal plasma is believed
to enter the middle corona in a subsonic state, then accelerate to exit the
zone generally with supersonic, but sub-Alfvenic flows. The estimated sonic
point for the low-heliolatitude latitude corona was 4 Rs; the sonic speed
transition may prove to be a robust feature of the middle corona.
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Wilson L. B. III
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Accurate Measurements of Thermal Velocity
Distribution Functions in the Solar Wind [#2002]
The
current state-of-the-art thermal particle measurements in the solar wind are
insufficient to address many long-standing, fundamental physical processes.
The solar wind is a weakly collisional ionized gas experiencing collective
effects due to long-range electromagnetic forces. Unlike a collisionally mediated fluid-like Earth’s atmosphere, the
solar wind is not in thermodynamic or thermal equilibrium. For that reason,
the solar wind exhibits multiple particle populations for each particle
species. We have already observed the electron populations of the core, halo,
strahl, and superhalo. We
have observed a proton core and secondary proton beam in addition to the
alpha-particle beam of the solar wind ions. However, we have not been able to
resolve each of these populations for subcomponents analogous to the electron
populations due to instrumental limitations.
MMS has taught us that higher resolution measurements lead to paradigm-shifting
results. This should not be surprising, but we will not be able to address
the fundamental kinetic physics of the solar wind, collisionless
shock waves, magnetic reconnection, wave-particle interactions, turbulence,
etc. unless we can fully resolve the particle velocity distributions for both
ions and electrons because each population responds differently to a common phenomena.
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Winslow R. Scolini C.
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On the Importance of Investigating ICME Complexity Evolution
During Propagation [#2072]
Interplanetary
coronal mass ejections (ICMEs) are the main source of adverse space weather
in the inner heliosphere. These large-scale transients, characterized by
intense and highly-twisted magnetic field bundles,
often drive fast-forward interplanetary shocks and turbulent sheaths, as well
as contain prolonged periods of southward pointing magnetic field. The
interaction of ICMEs with other interplanetary structures, including the
heliospheric current sheet, solar wind streams and interaction regions, and
other ICMEs, can drastically alter their global and local properties during
propagation, and increase their complexity. Fundamental research on ICME
complexity changes during propagation is critical to our physical
understanding of the evolution and interaction of transients in the inner
heliosphere. A complete understanding of such changes is required to
understand the space weather impact of ICMEs at different planets.
In-situ measurements carried out by spacecraft in close radial alignment are
critical to advance our knowledge on ICME evolution, and can, in turn, help
refine current space weather forecasting models. Yet, the scarcity of radially-aligned ICME crossings at this time restricts
such investigations to a few case studies, preventing a comprehensive
understanding of ICME complexity changes. Recent advances in this research
area derive from investigations that combine data from both planetary and
heliophysics missions, as well as numerical simulations. Results from these
studies provide compelling evidence that the interaction with large-scale
corotating solar wind structures significantly increases the complexity of
ICMEs as they propagate in interplanetary space. Future spacecraft placed in
optimal spatial configuration could greatly advance the field in this area,
once and for all answering the underlying question: what are the causes of the drastic
alterations observed in some ICMEs during propagation, while other ICMEs
remain relatively unchanged? Thus, there is a real need at this time for numerical
studies assessing the optimal spatial configuration required by future
missions to effectively close the current observational gaps. Furthermore,
including a magnetometer (and preferably also a plasma spectrometer) on all
future planetary and heliophysics missions would greatly extend the number of
events available for possible large-scale statistical studies, alleviating
the urgent need for dedicated missions on this topic.
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Young P. R.
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Magnetic reconnection: UV Bursts — A Case for Hi-Res EUV Images,
Spectra, and Magnetograms [#2116]
Magnetic
reconnection is being studied in Heliophysics through in situ measurements in
the Earth’s magnetosphere and through remote sensing in the solar atmosphere.
The former gives point measurements of the microphysics while the latter
allows the macroscale properties of flow, topology
and temperature to be studied through the lifetime of the reconnection event.
Both types of measurement are critical to understanding how reconnection
transfers energy from the magnetic field to the plasma.
Ultraviolet bursts are a class of reconnection event occurring in the solar
atmosphere that arguably give the best access to the reconnection physics.
They are heated to temperatures of 100 kK in
regions where the plasma is physically very thin, thus the UV bursts give a
very strong signature in spectral emission lines, both in intensity and
Doppler shifts/broadening. This is in contrast to
the corona that has a large line of sight. In addition, the magnetic field
evolution driving the events is clearly established through photospheric magnetograms.
To make progress on understanding UV bursts requires similar instrumentation
to what we have now (EUV imagers, UV/EUV spectrometers and magnetographs),
but with higher spatial and temporal resolutions, and better spectral
coverage. Heliophysics must continue to advance these technologies as it has
done for the past 25 years to make progress in understanding the fundamental
physics of the solar atmosphere.
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Authors
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Poster Title and Abstract
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Argall M. R. Smith A. W. Turner D. L. Shuster J. Vines S. K. Keesee A. Ferdousi B. Fuselier S. A. Azari A. Gabrielse C. Claudepierre S. Hwang K.-J. Bloch T. McGranaghan R. M. Slavin J.
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Intelligent Missions in a Living Heliophysics
System Observatory [#2134]
By
2050, the Heliophysics System Observatory (HSO) will consist of satellite
swarms and constellations that generate untold quantities of data. In
addition, the HSO archive will consist of the retired single- and
multi-spacecraft mission data that paved the way to 2050. To maximize the
science return of a growing HSO and leverage the vast potential of past
missions and their large data sets, next-generation missions need to
incorporate artificial intelligence, machine learning, and data mining
approaches (AI) into their science objectives and mission architectures from
the ground up. This includes developing AI-capable hardware, creating
resource-limited models for in-flight data evaluation, recognizing changing
data quality, and encouraging science discovery through AI applications.
It also includes investing in infrastructure to support these
objectives: a centralized cloud
database for AI-ready datasets, support of open source
software initiatives, and services to host and run AI models.AI is beginning
to gain a foothold in Heliophysics but is already enabling a more holistic
use of the active and retired HSO. For example, AI methods have allowed us to
take local, point measurements from single or multiple missions, and
transform them into global, dynamic models; to discover empirically the first
principles equations that govern particle transport; and to enhance numerical
simulations by providing empirical constraints. This is all supported by a
grass-roots community effort to develop open source
software for data analysis and model development, AI training to support
community demand, and infrastructure to distribute and validate models and
datasets. For the HSO archive of 2050 to be a living entity relevant to the
efforts and direction being taken by the community today, Heliophysics needs
a platform to centralize and standardize these efforts.
AI has yet to be applied in the design of a major science mission in
heliophysics. A near real-time AI model has been implemented on the ground by
the MMS mission to select mission-critical data for downlink; however the majority of on-board downlink-selection
schemes relying on simple models and look-up tables. Most urgently, the HSO
requires investments in rad-hard GPUs and processors paired with
opportunities to improve their technical readiness. To manage the data
volumes anticipated in the HSO of 2050, we need investments in AI-ready
flight systems and intelligent mission design today.
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Bonnell J. W. Lejosne S. Mozer F. S. Goodrich K.
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A Path Towards Revolutionary Improvements in 3D Fields and
Plasma Measurements [#2057]
Electrodynamics,
the exchange of energy and momentum between the electromagnetic field and
charged particle populations, plays a significant role in determining the
coupling between solar outputs and terrestrial or planetary responses at
macroscopic and microscopic scales throughout heliospace.
Key aspects of this exchange remain unclear, and further scientific progress
requires more accurate and complete measurements of both fields and
particles.
Focusing on the electromagnetic field, one finds that the current state of
the art in quasi-static electric and magnetic field measurements routinely
makes 2D measurements with accuracies often better than +/- 1% using long
wire boom systems on rotating spacecraft. However, achieving such accuracies
for the fully 3D E and B fields required for further progress remains
elusive. The axial antennas for E-field measurements are kept shorter than
the radial by SC dynamic stability constraints, leading to systemic offsets 1
to 2 orders of magnitude larger than the quantity measured, and thus in the
final field measurements themselves and any electrodynamics derived from
them. Similar issues arise in the measurement of 3D magnetic fields, as well
as plasma distributions with sufficiently rapid cadence and accuracy for
drifting and asymmetric distributions.
While efforts to refine the design of 3D field and plasma measurements on
spinning spacecraft continue, a much more accurate path to the goal of
routine, high-accuracy 3D measurements exists. This
path consists of mounting two sets of highly accurate 2D field (or particle)
sensors on a pair of orthogonal rotating platforms that are in turn mounted
to a three-axis-stabilized spacecraft bus. The evolution of integrated
instrument suites allows for a far simpler power and data interface to the
platform-mounted packages than on prior dual-spin missions making such a
design quite feasible. This twin platform design allows the end user to
combine easily and routinely the measurements from the two sets of 2D
measurements into a single high-accuracy instantaneous 3D measurement of the
fields and particle distributions. Such a twin orthogonal rotor platform
(TORP) system has been under study for over 10 years and shows great promise
both in terms of the uniform improvement in accuracy of such 3D measurements.
Here, we shall present the case for the need for such a revolutionary
improvement and results of the ongoing TORP design and
development effort.
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Borovsky J. E. Delzanno G. L. Gilchrist B. E. Heelis R. A. Henderson M. G. Johnson J. R. Kepko L. Marshall R. A. MacDonald E. A. Reeves G. D. Ruohoniemi J. M. Rowland D. E. Sanchez E. R. Semeter J. Sojka J. J. Spanswick E. Donovan E. Turner D. L. Wing S. Varney R. Zou S.
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The Uncertainty of Nightside
Magnetosphere-Ionosphere Magnetic Connections: Critical Progress Since the Call in the
Last Decadal Survey [#2083]
On the
Earth’s nightside, the magnetic connections between the ionosphere and the
non-dipolar magnetosphere have a great deal of uncertainty: this prevents us from understanding what
magnetospheric processes are driving various phenomena in the ionosphere.
Magnetic-field models are not accurate enough in the time-varying nightside
magnetosphere to establish detailed magnetosphere-ionosphere connections and
it is unlikely that breakthroughs in these models will be achieved. Because
of these facts, “Magnetosphere-to-Ionosphere Field-Line Tracing Technology”
using an energetic electron beam fired from a magnetospheric spacecraft has
been called out in the NRC 2013 Solar and Space Physics Decadal Survey (pp.
333–334) as an “instrument development need and emerging technology”.
A key example of how the uncertainty impedes us is the outstanding
question of how the magnetosphere drives auroral arcs: a
number of mechanisms are hypothesized in the literature, but
equatorial magnetospheric measurements have not been unambiguously connected
to arcs in the ionosphere, preventing us from identifying the correct
generator mechanisms. Essentially, it is not known what form of energy is
tapped from the magnetosphere to drive arcs, preventing us from assessing the
impact of aurora on the magnetosphere. A celebrated desire has been to use
auroral observations as a “TV screen” to interpret ongoing magnetospheric
processes: this has not been accomplished. Other problems require precise
specification of magnetic connections between magnetospheric and ionospheric
processes such as SAPS, SAID, STEVE, convection reversals, ionospheric
density structures, bursty bulk flows, and omega
bands and the mapping of boundaries the magnetosphere and the ionosphere.
With precise knowledge of the magnetic connection, magnetosphere-ionosphere
convection coupling could be studied by comparing temporal onsets of
convection in the magnetosphere (via spacecraft measurements) with temporal
onsets of ionospheric convection at the magnetic footpoint
(via ground-based measurements), which could answer questions about when and
where (a) the magnetosphere drives ionospheric convection and (b) the
ionosphere drives magnetospheric convection. Since the last Decadal Survey
substantial progress has been made on this much-needed technology
development. This presentation will focus on the progress to date in solving
the magnetic field mapping problem and the outlook for the future.
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Burkholder B. L. Nykyri H. K. Ma X.
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2-Dimensional Solar Wind Propagation from L1 to Earth [#2121]
The
interaction of the solar wind with Earth and other obstacles in the solar
system is a 3-dimensional problem. The fleet of solar wind monitoring
spacecraft orbiting the L1 point upstream of Earth have orbits that often
give them large separations in the azimuthal direction. This makes it
possible to resolve azimuthal gradients in the solar wind and furthermore,
when these gradients are sufficiently strong, predict when conditions may be
different on the dawn vs. dusk flanks. I will introduce our simple method to
resolve the 2-dimensional structure of the solar wind and discuss potential
impacts of different solar wind conditions on the dawn vs. dusk flanks of
the magnetosphere.
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Buzulukova N. Fok M.-C. Sibeck D. Keesee A. Connor H. Collier M. DeMajistre R. Glocer A. Murphy K.
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Global Imaging in Energetic Neutral Atoms: Tracing Energy Pathways [#2094]
The
Earth’s magnetosphere is a complex system that interacts with the solar wind,
ionosphere and neutral gases of atmosphere and
geocorona. Despite tremendous progress, the community is not at the stage
where a reliable prediction and description of all desired variables can be
achieved. One of the major problems is that local measurements are very
sparse. Local satellite measurements often allow multiple interpretations,
and consequently different solutions for the global state of the
magnetosphere. Recent attempts to solve this problem using the
state-of-the-art first-principles global models are promising; however, global
models taken alone are not currently ready to predict the global state of the
magnetosphere.
This presentation highlights Energetic Neutral Atom (ENA) imaging as a tool
to address two key science challenges of Heliophysics, namely: “How does magnetic reconnection drive mass,
momentum and energy transport” and “What are the mechanisms to control the
production, loss and energization of magnetospheric plasma”.
Previous ENA missions IMAGE and TWINS have significantly improved the
knowledge on the structure and dynamics of the Earth’s magnetosphere,
measuring ENA emissions primarily from the ring current region. It is
anticipated that future missions with enhanced angular resolution and
sensitivity will be able to measure ENAs from the plasmasheet,
reconnection exhaust in the tail and dipole transition region, and
differentiate between modes of magnetospheric behavior, i.e., substorms,
steady magnetospheric convection, sequential bursty
bulk flows etc. With favorable viewing geometry, they can relate the occurrence
of tail bursty flows and ion injections in the ring
current, their azimuthal extent and composition on a case-by-case and
statistical basis for each event category. We conclude that the global
imaging is a very effective way to understand the dynamics of the whole
system, and to constrain the global models. The synergy between global
modeling and global imaging will ensure the science closure for many open
questions in magnetospheric physics and improve predictive capabilities for
space weather applications.
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Chakraborty S. Fiori R. A. D. Bland E. C. Ruohoniemi J. M. Baker J. B. H.
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Observing and Modeling Space Weather Phenomena in the Ionosphere [#2168]
The Sun
is a variable star that evolves with time via tangling, crossing, and
reorganizing magnetic fields. The magnetic activities on the Sun create
disturbances, which manifest as solar flare (SF), solar energetic proton
event (SEP), and coronal mass ejection (CME). SFs, SEPs, and CMEs, which form
on the Sun’s corona, travel through the interplanetary space
and reach Earth in ~8 minutes, ~30 minutes, and ~3 days, respectively. These
solar activities, commonly referred to as space weather, deposit energy into
Earth’s upper atmosphere (ionosphere) and create disturbances in near-Earth
space or geospace. Geomagnetic storms, sudden
ionospheric disturbances (SIDs), ground induced currents (GIC) are a few
examples of impactful space weather phenomena. Ionospheric properties such as
conductivity and electron density are strongly affected by space weather. The
ionosphere has significant implications for modern technology, including
long-distance communication, global satellite positioning systems,
atmospheric drag on LEO satellites, and GICs. Sudden changes in ionospheric
properties due to extreme space weather can have severe and disruptive
impacts. A comprehensive understanding of ionospheric properties and their
variability will enable us to gain insight into ionospheric physics and
energy coupling mechanisms and mitigate these impacts. Initially, it was
thought that space weather-driven phenomena alter ionospheric properties only
at auroral regions (high latitudes); however, with the establishment of new
ground-based instruments and spacecraft missions, it is now clear that space
weather also impacts technology at the middle, equatorial, and polar
latitudes. The research community should target the fundamental physics of
the active ionosphere, including conductivity, plasma instability, and the
formation of density irregularities, ionospheric current, plasma-neutral
coupling, etc., and the related spatiotemporal dynamics during space weather.
We argue for the value of global-scale observations of the
ionosphere-magnetosphere system that support conjunction studies using
ground-based and space-borne instruments. Now that multi-decadal datasets are
available, machine learning and neural-network-based studies can help with
sorting out the sources and pathways for the global-scale impacts of space
weather on the ionosphere. Ultimately we should aim
to complete our understanding with comprehensive first-principles modeling
that provides a predictive capability.
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Chen L.-J. Samara M. Michell R. Collier M. Dorelli J. Fung S. Gershman D. Karpen J. Ng J. Rowland D. Sibeck D. Wang S. Halford A. Zesta E. Giles B. Vasko I. Stawarz J. Turner D. Paterson W. Madanian H. Wilson III L.
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Kinetic Effects of Solar Driving
on Magnetospheres [#2122]
We
discuss kinetic effects of solar driving on magnetospheres and interconnected
science topics envisioned for future major research directions in
heliophysics. We recommend (1) promotion of global particle simulations to
address how these kinetic effects impact the evolution of magnetized planets
and bodies in the heliosphere, past and present; and (2) advancing NASA’s
high-end computing to exascale to provide the
critical ground for (1). An underlying connection between collisionless
shocks, turbulence, and magnetic reconnection leads to complex interactions
in the geospace environment. Below are example
topics for major future investigations to be discussed in the poster.
*Collisionless shock physics: magnetic field amplification, particle
acceleration, cross shock dissipation, 3D shock structures and dynamics, wave
excitation and interaction with particles.
*Evolution of magnetized bodies: how
does kinetic turbulence due to reflected particles at the bow shock affect
the evolution of magnetized planets and bodies in the universe, past and
present?
*Turbulent reconnection: how foreshock
and magnetosheath turbulence impacts the
magnetopause processes such as reconnection and Kelvin-Helmholts
instability, for example. Furthermore, the nature of reconnection varies with
scale size. Reconnection in electron-scale turbulence precludes ions from
participating in the dynamics, hence the energy conversion process and
evolution in kinetic turbulence call for new examination.
*Impact on the magnetosphere-ionosphere-thermosphere: What are the MIT responses to the shock
turbulence both in terms of the amplified fields and energized particles?
*Impact on the magnetotail: Turbulence
affects the dayside reconnection rate which influences magnetic flux
circulation, and hence magnetotail dynamics.
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Chi P. J. Damiano P. A. Denton R. E. Ferdousi B. Jorgensen A. M. Lin N. Lysak R. L. Raeder J. Takahashi K.
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Magnetoseismology Research for the Next Decade [#2107]
Magnetoseismology is a unique and well-demonstrated method to investigate the plasma
structures and dynamics of the magnetosphere. The normal-mode method examines
the widespread field line resonance in the magnetosphere to estimate the
plasma mass density that is difficult to infer through other measurements.
The travel-time method tracks impulse propagation in the magnetosphere and
has enabled new capability of remotely monitoring sudden impulses and
substorm onsets that are rarely measured on-site. The two methods of magnetoseismology bear substantial resemblance to the
techniques used in terrestrial seismology and helioseismology that have
advanced our understanding of the interior of the Earth and the Sun.
Several research areas require
major efforts to be able to advance magnetoseismology
in the next decade. Even though an abundance of ground-based and spacecraft
measurements of field line resonance have been collected through past
projects, coordinated multi-point observations for normal-mode magnetoseismology research were rarely conducted. Implementation
of additional ground-based magnetometer stations to form dense magnetometer
chains in American, European, and Asian sectors can enable global monitoring
of the plasma mass density in the inner magnetosphere. In addition,
identifying field line resonance frequencies in large databases is very
time-consuming and requires expert experience, and the incorporation of
machine learning or other data analysis techniques into the process can help
remove these technical hurdles. Travel-time magnetoseismology
is a relatively young research topic, where the forward model involves
impulse propagation in highly inhomogeneous plasmas. Characteristics of
signal propagation require validation by global magnetosphere simulations and
new satellite missions that are designed to time the arrivals of impulse
arrivals at multiple distances in a systematic fashion. These near-term
investigations will facilitate the development of magnetoseismology
and help the two techniques become common means of Heliophysics research by 2050.
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Coster A. J. Huba J. D. Sazykin S. Y.
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Developing a Modeling Framework for
Understanding Hemispheric Asymmetries via Model-Data Comparisons [#2150]
Asymmetries
in a variety of ionospheric phenomena related to magnetospheric-ionospheric
coupling between the different hemispheres arise due to the geographic and/or
geomagnetic properties of the Earth, as well as effects that arise directly
from the solar wind and its magnetospheric consequences. A few examples
phenomena displaying asymmetrical coupling include magnetic pulsations, ion
outflows, field-aligned currents, electromagnetic energy (Poynting) flux,
auroral particle precipitation, high-latitude ionospheric convection,
ionospheric electron densities and thermospheric
winds and mass densities. Many of these hemispheric asymmetries can be traced
back to a handful of fundamental causes including interplanetary magnetic
fields, solar illumination, Earth’s magnetic field (e.g., different offsets
between magnetic and geographical poles, differences in field strength at
conjugate regions, displacement of the magnetic equator from the geographic
equator) as well as land-sea distribution. There are also hemispherical
differences at the mid and low latitudes, and associated coupling processes
between the hemispheres (e.g., magnetic lines of force, winds, and
electrodynamics), that lead to differences in the neutral atmosphere and
plasma. Interpretation of various observations and understanding causes and
mechanisms of hemispheric asymmetries requires development of a
first-principles numerical model of the ionosphere-thermosphere-magnetosphere
system capable of handing asymmetries. Such a model
will also serve as a framework for interpretation of experimental results
from an increasing number of data sources, and would
be a necessary development for making advances in the ITM science.
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Coster A. J. Erickson P. J. Hysell D. L. Kendall E. Varney R. H.
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The Potential for Community Science with Future Incoherent Scatter
Radar Observations [#2143]
The technique
of collective Thomson or incoherent scatter (IS) radar has been employed
since the 1960’s to provide comprehensive, fundamental insights into the
state of the ionosphere and its thermal parameters in a way not matched by
any other remote sensing technique. This technique directly, and uniquely,
measures full altitude profiles of the most fundamental ionospheric
parameters including electron density, electron temperature, ion temperature,
plasma velocity, and ion composition. These basic state variables with
varying assumptions then allow further derivation of such key quantities as
electric field strength, conductivity, electric currents, neutral
temperature, and neutral wind velocity. Taken in aggregate, no other
technique is comparable in the range of ionospheric and thermospheric
parameters provided for synoptic and detailed scientific studies.
IS radar’s unique observation power
stems from its use of a precise theoretical model derived from fundamental
constants and first-principles plasma theory, applied to properly interpret
very weak ionospheric backscatter measured using large aperture antennas and
powerful transmitters. IS measurements have played
and continue to play a critical role in community atmospheric and ionospheric
model development and verification. For example, IS measurements have helped
produce the widely used MSIS neutral atmosphere model and the International
Reference Ionosphere (IRI). In recent years, IS measurements have also been
used to validate and amplify in-situ satellite measurements from a number of different missions in system scale studies. In
general, IS radar characterizations of ionospheric and thermospheric
dynamics are a mainstay of community knowledge and understanding of large and small scale processes and features within the
tightly coupled magnetosphere-ionosphere-thermosphere system. In the coming
decades, the power of ISR’s will rapidly expand with new advances in
hardware, software, and signal processing. These will provide new
capabilities for community studies, such as volumetric images of ionospheric
plasma parameters using aperture synthesis radar imaging, including
three-dimensional images of the movements of different ionospheric
constituents, and enhanced observations of the temperature, density of different
atmospheric species and the intensity of electrodynamic coupling.
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Delzanno G. L. Borovsky J. E. Buzulukova N. Chappell C. R. Denton M. Fernandes P. Friedel R. Gallagher G. Goldstein J. Henderson M. Larsen B. Jordanova V. Maldonado C. Moore T. Reisenfeld D. Roytershteyn V. Skoug R. Varney R.
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The Need to Understand the Cold-Ion and Cold-Electron
Populations of the Earth’s Magnetosphere [#2089]
The
Earth’s magnetosphere comprises multiple ion and electron populations with a
broad range of energies, from the sub-eV particles of the ionosphere to the
relativistic particles of the radiation belts. These diverse particle
populations are co-located and interact through a variety of processes,
including various plasma waves.
While the warm (ring current/plasma sheet) and hot (radiation belts)
populations have received a lot of attention in part because of their
potential harm to space infrastructure, the cold populations (with energy
less than ~100 eV) are the least studied and in some cases have been referred
to as the ‘hidden populations’. This is because spacecraft are typically
charged to levels that make measuring the cold plasma properties very
difficult and sometimes impossible. For electrons, an additional complication
is that spacecraft surfaces exposed to sunlight and bombarded by energetic
particles emit secondary electrons with energies comparable to those of the
cold electrons of the environment that can completely dominate the detector
measurement.
However, the cold plasma has a strong impact on many phenomena that are
critical to the dynamics of the near-Earth environment, both locally and
globally. Examples include the cold plasma being the source of hot
magnetospheric plasma, solar-wind/magnetosphere coupling, tail reconnection
and substorm dynamics, wave-particle interaction physics, plasmasphere/plasmasheet interactions and structuring of the pulsating
aurora. Given the sparsity of measurements and the generally poor
understanding of the cold populations, it is plausible that other impacts not
yet known might exist. In all, this leaves a major gap in our understanding
of the magnetosphere-ionosphere system.
In preparation for the next decadal survey for space physics, this
presentation will highlight (1) the known and probable impacts of the cold
populations in magnetospheric physics; (2) the need for new measurement
techniques; (3) the need for a data-analysis effort to use available data to
survey the cold-particle populations, understand their origin, drivers and
controlling factors; (4) the need for a theory/modeling program (including
merged ionosphere/magnetosphere models) to understand the impacts of the cold
populations and how to include those impacts in the next generation
space-weather models; and (5) the need for new space missions to perform
comprehensive in-situ and remote measurements of the cold-particle populations.
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Donovan E. Borovsky J. McGranaghan R. Angelopoulos V. Spanswick E.
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The Observations We Need for System Science [#2070]
Geospace dynamics are inherently multi-scale. Ultimately, everything is
accomplished on a foundational level through small-scale fundamental physical
processes like reconnection, wave-particle interactions, turbulence, and
plasma instabilities. In the magnetosphere these processes can only be
studied via in situ observations, and in the ionosphere these scales can be
explored by in situ observations on low-altitude spacecraft, LIDARs and ISRs.
All of these techniques provide either true point
measurements, or observations from small regions (ISRs).
Although critical for understand
how geospace works, they do not tell the whole story.
There are processes that unfold over larger scales that are still small
compared to the overall system, processes that in geospace
are the equivalent of tides, currents, and Tsunamis in ocean dynamics. These
processes, which include Bursty Bulk Flows (BBFs),
plasma injections, ULF waves, MHD waves and instabilities, Sub-Auroral Ion
Drifts (SAIDS), and as yet to be understood
processes that determine the extent of regions over which specific
small-scale processes occur. Three examples of the latter are whatever
determines the size of a reconnection region, the size and shape of auroral
patches in the morning sector, or the narrow north-south and very long
east-west shape of auroral arcs. These are meso-scale and multi-scale
processes, and we argue these are as critical to the dynamics of geospace as the underlying small-scale processes. These
are the processes by which the immediate and local effects of the small-scale
processes ‘spin up’ to have regional/global-scale consequences. These are the
drivers of space weather.
The desire to explore these
meso-scale processes was the driver for the ISTP, and
is what motivates constellation class satellite missions such THEMIS and the
planned Magnetospheric Constellation mission. Still, although THEMIS has
been, and MagCon will be, revolutionary, the
spacing between point measurements is large compared to, e.g., the width of a
BBF, size of an auroral patch, or that of whatever gradient in the
magnetotail is the ‘root’ of an arc. Imaging of processes in the ionosphere,
and in particular the aurora, is perhaps our most powerful tool for exploring
the real structure of these mesoscale processes and their magnetospheric or
ionospheric drivers.
In this paper, we explore the need
for multi-scale (in time and space) observations of key regions and
parameters in geospace, and for simultaneous
observations of multiple geospace regions and
regimes. Our goal is to highlight how the need to understand the system
complements the need to understand the plasma.
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Dorelli J. C. Bard C. Buzulukova N. Khazanov G. Gallardo-Lacourt B. Kepko L. Michell R. Murphy K. Oliveira D. Samara M. Shuster J. Sibeck D. Zesta E.
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Understanding the Connection Between Multiscale
Magnetotail Dynamics and the Aurora [#2132]
Auroral
displays are among the most beautiful space weather effects observable from
Earth, capturing the imaginations of scientists and non-scientists alike.
Auroral substorms exhibit a bewildering, but repeatable, variety of complex
structure and dynamics, originating from kilometer scale arcs that brighten
rapidly over minutes before expanding over hours to turbulent storms hundreds
of kilometers wide. These auroral substorms are distorted two-dimensional
projections of complex multiscale dynamics in Earth’s magnetotail.
Understanding the physics of this connection remains one of the most
challenging problems in heliophysics. Previous NASA missions, like THEMIS and
MMS, have solved important pieces of the puzzle, but fundamental questions
remain. THEMIS provided an essentially one-dimensional picture of the
evolution of magnetotail dynamics from the mid-tail to the inner
magnetosphere, but the connection to the aurora involves the cumulative
influence of many mesoscale structures distributed in the cross-tail dimension.
MMS was the first “magnetospheric microscope” to resolve the kinetic scale of
magnetic reconnection, thought to play an essential role in the onset of
auroral substorms; but MMS cannot observe the physical processes, occurring
over many thousands of kilometers along magnetic field lines, that connect
magnetic reconnection to the aurora. To make progress on this problem, our
community needs to work together to develop the next generation of global
models and mission concepts.
In this poster, we describe some of the modeling advances that will be needed
to accurately simulate auroral substorms. Since the aurora results from the
collisional interaction of precipitating electrons with Earth’s atmosphere, a
key element in any predictively powerful global model will be the
self-consistent transport of electrons from the collisionless
plasma sheet to the collisional ionosphere. We discuss the computational
challenges involved in achieving this ambitious goal. Additionally, we
outline some of the observations that will be needed to test this new
generation of global models. These include constellations of satellites to
achieve global magnetic local time coverage in the dipole transition region,
fast (10s of ms) particle measurements to resolve
the electron edge of the plasma sheet boundary layer, coordinated in situ
observations at multiple altitudes (ranging from LEO to the auroral
acceleration region), and multispectral auroral imagers on the ground.
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Eastes R. W. Burns A. G. Greer K. R. Gan Q. Laskar F. I. Solomon S. C. McClintock W. E.
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Global Remote Sensing of the Thermosphere-Ionosphere System — A
Catalyst for Advances in 2050 and Beyond [#2045]
Remote
sensing provides essential information for advances in understanding and
forecasting the Earth’s Thermosphere-Ionosphere (T-I) system. The Earth’s T-I
is a dynamic system. Changes in the energy inputs from the Sun and the
Earth’s magnetosphere can alter the entire system within an hour or less.
Another large source of energy, about which we have insufficient knowledge,
is from the lower atmosphere. Determining how the thermosphere-ionosphere
(T-I) system responds to these drivers on a global-scale is essential to
understanding the system’s behavior and to future space weather forecasting
advances. Advancing our understanding of the T-I system’s spatial and
temporal response requires relatively small-scale observations of the T-I
environment within a simultaneous global-scale view of the T-I system’s
response within the Sun-Earth system. Some essential remote sensing
capabilities for accomplishing this, using both low and geostationary Earth
orbit, have been established in recent decades. A logical next step is
combining them to make global observations capable of following the temporal
(an hour or less) and spatial (order of 10 km vertical and 100 km horizontal)
changes that occur. An expansion of such capabilities would enable advances
in modeling and assimilation capabilities for the T-I system and in our
understanding of its interaction with other parts of the
Earth-Sun system.
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Elias A. G. Zossi B. S. Medina F. D. Gutierrez Falcon A. R. de Haro Barbas B. F.
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Implications of Solar Activity and Geomagnetic
Field Secular Variations on Long-Term Trends Estimation [#2043]
Several
aspects of aeronomy and space weather are modulated by variations in
geomagnetic field and in solar activity as well. In
particular, secular variations in both may have comparable effects in
terms of magnitude for certain processes. A difference between their effects
could be the spatial pattern of their consequences in, for example, charged
particle flux reaching the Earth’s atmosphere. While the expected solar
modulation is more spatially homogeneous, in the sense that increasing or
decreasing solar activity may have the same effect for every location in our
planet, the geomagnetic field modulation may depend on location. A comparison
of the secular variation in both forcings is
analyzed in parameters characterizing the ionosphere and charged particles
entering the atmosphere, emphasizing its implication in long-term
trend assessments.
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Fernandes P. A. Delzanno G. L. Denton M. H. Henderson M. G. Jordanova V. K. Kim T. K. Larsen B. A. Maldonado C. A. Reeves G. Reisenfeld D. B. Skoug R. M.
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Heavy Ions: Tracers and Drivers
of Solar Wind/Ionosphere/Magnetosphere Coupling [#2142]
Much of
our knowledge of the composition of plasma in space comes from decades-old
measurements. The mass spectrometers of the 1970s, 1980s, and 1990s
outperformed most contemporary instruments, due to changes in the funding
landscape and shifting community perspectives of the necessity of various in
situ measurements. The dearth of modern composition measurements in space and
our poor understanding of differences in plasma processes driven by different
heavy ions inhibit our ability to predict and characterize natural and
man-made events in the near-Earth space environment.
Significant advances in technology over the last several decades, including
both digitization and hardware miniaturization, enable more sophisticated
mass spectrometers in smaller design packages than ever before. Looking to
the future, we propose a community goal of characterizing the full complement
of plasma species (composition and charge state) within the Solar
Wind/Ionosphere/Magnetosphere (SW/I/M) system to understand how these populations
interact with one another and impact the system as a whole.
Focusing on the next decadal survey
and extending to the vision of the state of Heliophysics research in 2050, we
discuss a cost-effective solution for bringing high-resolution in-situ mass
spectrometers to the forefront of major space missions. In particular, we
present: (1) a brief comparison of
past and present mass spectrometer capability; (2) our current understanding
of the role of heavy ions in the SW/I/M system; (3) unresolved questions
within the SW/I/M system that will be addressed by modern plasma composition
measurements; (4) proposed programs to modernize and provide flight heritage
to novel mass spectrometer instruments; (5) the need for complementary space
missions to treat the SW/I/M system as a coupled system and not as distinct
regions studied by different communities.
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Gabrielse C. Nishimura Y. Deng Y. Lyons L. R. Chen M. W. Hecht J. H. Merkin V. G. Gkioulidou M. Turner D. L. Malaspina D. Birn J. Ohtani S. Liu J. Lui A. McPherron R. L. Sheng C. Sorathia K.
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Mesoscales and Their Contribution to the Global
Response: A Focus on the Magnetotail
Transition Region and Magnetosphere-Ionosphere Coupling [#2053]
The
broad but important question that is being increasingly studied across
subdisciplines of Heliophysics is “how do mesoscale phenomena contribute to
the global response of the system?” This poster focuses on this question
within two specific but interlinked regions in Near-Earth space: the magnetotail and its transition region
to the inner magnetosphere, and the ionosphere. With regards to the
magnetotail transition region, a Geospace
Environment Modeling (GEM) Focus Group has been studying if and how much
mesoscale transport in the tail contributes to the more global response at
the transition region with respect to magnetic flux and dipolarization,
particle transport and injections, and the substorm current wedge. The
magnetosphere-ionosphere is a directly coupled system that feeds into one
another; therefore, this poster also discusses the question of mesoscale
contributions from related plasma flows and auroral precipitation to the more
global energy flux deposited and the resulting conductance. We see these
specific open questions as part of the larger need to address these
mesoscales in order to understand the global system,
suggest some types of datasets that, if developed in the future, could help
answer these questions, and welcome your thoughts and discussion on
moving forward.
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Genestreti K. J. Turner D. L. Argall M. R. Baumjohann W. Birn J. Bortnik J. Burch J. L. Chen Y. Claudepierre S. Cohen I. J. Fuselier S. A. Gabrielse C. Hwang J. Ieda A. Kiehas S. Kistler L. M. Lin Y. Liu Y.-H. Merkin S. Motoba T. Mouikis C. G. Nagai T. Nakamura R. Nakamura T. K. M. Ogasawara K. Panov E. Plaschke F. Runov A. Sitnov M. Slavin J. A. Spence H. E. Stephens G. Sun W. Torbert R. B. Tsyganenko N. Vines S. K. Wang C.-P.
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Open Questions in Magnetotail Physics [#2139]
Magnetic
reconnection is a universal process that powers explosive phenomena in space
and laboratory plasmas. Reconnection in Earth’s cis-lunar magnetotail drives
rapid magnetospheric reconfiguration during geomagnetic storms/substorms and
increases – often dramatically – energetic particle radiation levels
throughout cis-lunar space. Reconnection is a fundamentally local and
micro-scale process; though, like any other process of consequence,
cross-scale and cross-region coupling is an inescapable certainty.
Understanding the coupling between reconnection at these smallest scales (~10–4
RE3) and the much larger magnetosphere (~10+4 RE3)
is no small feat, due in large part to the dramatically different spatial
scales. Magnetospheric Multiscale (MMS) has transformed our understanding of
the fundamentally micro-scale process by investigating reconnection physics
at the smallest plasma scales in space and time. Contextualizing the
micro-scale revolution of MMS is the next major advancement and is required
to quantify the impact of reconnection on near-Earth space. In this poster,
we discuss three major open questions regarding reconnection in Earth’s
nightside magnetotail.
(1) What are the conditions of the magnetotail in the moments before
reconnection starts, and how do these conditions affect the reconnection
process?
(2) What is the azimuthal extent of magnetotail reconnection what is the
connection between reconnection and azimuthally-confined plasma flows and
large-scale plasmoids?
(3) How do energetic particles gain energy from multi-scale transient
structures in reconnection exhausts?
These questions should be addressed
by the community as soon as possible so that Heliophysics in 2050 may target
the much broader coupling between microscopic reconnection and geospace, and
apply these “lessons learned” to reconnection beyond the Earth.
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Hartinger M. D. Engebretson M. J. Salzano M. L. Olabode A. Ozturk D. S. McGranaghan R. Shi X. Kim H. Connors M. G. Xu Z. Weygand J.
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Towards a Better Understanding of the Causes and
Consequences of Geomagnetic Perturbations in 2050 [#2037]
Disturbances
in the magnetic field at the Earth’s surface, or surface geomagnetic
perturbations (BGEO), have played a major role in the development of
Heliophysics research, by (1) providing a remote sensing tool for electric
currents that define the electrodynamics of the magnetosphere-ionosphere
(M-I) system, (2) providing a wide range of diagnostics (geomagnetic activity
indices, model validation tools), (3) improving our understanding and ability
to predict geoelectric fields and geomagnetically induced currents (GICs).
Multiple factors contribute to BGEO simultaneously: the spatial and temporal scales of the M-I
source currents, ionospheric electrical conductivity and related spatial
gradients, the Earth conductivity and related
spatial gradients. Past work mostly examined these factors independently, but
multiple factors can affect BGEO simultaneously. The superposition of
multiple M-I current systems in BGEO further increases the complexity of this
problem. As a result, fundamental research is needed to improve our
understanding of the causes and consequences of BGEO. For example, addressing
the question, “How do the multiple spatial and temporal scales present in the
magnetosphere, ionosphere, and ground affect the generation of geomagnetic
fields, geoelectric fields, and GIC”? requires research targeting many
different multi-scale phenomena (e.g., interplanetary shocks, substorms and
auroral electrojets, wave activity) and observations and models that can
account for variability in the magnetosphere, ionosphere, and ground
simultaneously.
In the next 30 years, progress is needed in several areas: (1) more realistic ground conductivity
models incorporated into analysis of BGEO so that telluric currents can be
separated from M-I currents, (2) fundamental research to understand the
sources of BGEO along with targeted improvements in the spatial sampling of
BGEO by, for example, the development of low-cost, high-quality
instrumentation, (3) both fundamental and applied research to improve our
understanding of how the multiple spatiotemporal features of BGEO couple to
GIC, (4) both fundamental and applied research to improve space weather
forecasts that rely on BGEO, (5) all stakeholders who need BGEO measurements
should work together to intelligently design new coverage and instrumentation
requirements; governmental policies (e.g., interagency solicitations) are
needed to promote collaborations in this area.
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Huang S. Li W. Shen X. C. Ma Q. Chu X. N. Capannolo L.
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Hiss in the Plasmasphere and Plumes:
Global Distribution from Machine Learning Technique and Their Effects
on Global Loss of Energetic Electrons [#2048]
Whistler
mode hiss waves are typically observed inside the plasmasphere and plumes, and are known to play an important role in
energetic electron loss processes in the Earth’s inner magnetosphere. In particular, hiss in plumes is previously shown to be
stronger than the waves inside the plasmasphere; however, it has been
challenging to achieve the dynamic evolution of hiss inside the plumes on a
global scale. We use machine learning technique, more specifically,
artificial neural network (ANN) to construct the global evolution of total
electron density and hiss wave amplitude inside the plasmasphere and plume
and the associated hiss waves therein. These constructed hiss wave models are
used to quantify the effects of hiss on the global electron loss at L < 6
using the 3D Fokker Planck simulation. We demonstrate that neural network is able to reconstruct the dynamic evolution of total
electron density and hiss inside the plasmasphere and plume. Moreover, the
simulation result indicates that plume hiss can cause an efficient loss of
energetic electrons in the outer radiation belt.
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Hysell D. L. Milla M. A.
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An Ionospheric Modification Facility at the
Magnetic Equator [#2104]
We
propose the development of an ionospheric modification facility, sometimes
called an ionospheric heater, near the geomagnetic equator.
A heater is a powerful high-frequency (HF) transmitter that can induce a number of phenomena in ionospheric plasmas. Some of
these phenomena provide insights into complicated plasma physics processes
that may occur elsewhere in nature but that are impractical to explore in the
laboratory or numerically. Other processes provide diagnostics of naturally
occurring ionospheric phenomena at work. Ionospheric modification experiments
affect the propagation of radio signals passing through the ionospheric
volume, which is how the phenomenon was first discovered (i.e.
the Radio Luxembourg effect). They generate airglow and radio emissions which
can be observed from the ground. They create field-aligned plasma density
irregularities that can be interrogated by small coherent scatter radars.
They generate low-frequency radiation which has practical societal
utility. They also cause electron
acceleration. Finally, they modify
plasma density and electron and ion temperatures and enhance the plasma and
ion lines observed by incoherent scatter. They offer a way to study
cause-and-effect relationships that may be impenetrable to passive
experimental methods.
Important science questions: This
project addresses some of the most pressing basic science questions in AIM
including the physics behind electron acceleration, wave-wave coupling,
wave-particle interactions, and ionospheric instability. It also has the
potential of providing a new diagnostic of ionospheric parameters, rate
constants, and transport coefficients, adding to and going beyond what
incoherent scatter techniques already supply. The ability to probe the
neutral atmosphere via radio using the creation of artificial periodic
inhomogeneity (API) is novel.
Societal benefits and operations:
Low-frequency electromagnetic waves have an important strategic role
to play in the areas of submarine communication and subsurface remote
sensing. An equatorial heater represents a cost-effective means of achieving
the needed capability. ESF forecasting is important to a
number of space weather interests, but conventional research methods
are producing results only slowly. Active experiments with ionospheric
modifications could accelerate the progress by promoting controlled
cause-and-effect experiments.
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Jaynes A. N. Gabrielse C. Erickson P. J. Fang X. Halekas J. Harvey V. L. Marshall R. Blum L. Usanova M. E. Turner D. L. Kaeppler S.
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A Call for Interdisciplinary Science Focusing on How Particle
Precipitation from the Magnetosphere Affects Earth’s Atmosphere [#2151]
Truly
interdisciplinary science has the potential to create new paradigms and discover
exciting links between phenomena that occur across disciplines, thereby
changing our understanding of the system as a whole.
This kind of holistic treatment has been highly successful in other sciences,
even in our sister fields of Planetary and Earth science. Time and again,
interdisciplinary investigations have led to real breakthroughs.
Traditionally, Heliophysics has conducted research using a more
compartmentalized model. As an example, even the form to fill out before
submitting this white paper requires a Primary and Secondary categorization
from within the firmly established sub-disciplines. When studying how
particles from the Sun are processed by Earth’s magnetosphere and provoke a
response in Earth’s atmosphere, would one define the Primary subject to be
Heliosphere, Magnetosphere or ITM science? As we look forward to thirty years
from now, we should intentionally shift away from this kind of siloed science
and toward a more interdisciplinary approach to understanding the Sun-Earth
system.
To this end, we pose a specific
long-standing science question that connects multiple regions of geospace, yet
is still not understood. Energetic particle precipitation, known as EPP, is
the primary source of nitrogen oxides (NO and NO2), collectively known as
NOx, in the polar upper atmosphere. These NOx constituents are known to
catalytically destroy stratospheric ozone. But the contribution to polar
ozone loss of NOx produced by EPP, and the consequent effects on temperature
and winds, are poorly quantified. The atmosphere is necessary for the
existence of life on Earth, yet we still don’t
understand a critical component of this region: how energy from the Sun and from near-Earth
space is absorbed and transported in the middle and lower layers of the
atmosphere.
Here, we present a set of
compelling science questions that need answers in order to
fully understand this last link in the Sun-Earth system. It will require
researchers from both the magnetospheric and atmospheric fields working
together. And it will require support from the greater communities and
funding agencies to help build and maintain those bridges.
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Kepko L. Merking S. Viall N. Vourlidas A. McIntosh S.
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Mesoscale Dynamics — The Key to Unlocking the
Universal Physics of Multiscale Feedback [#2007]
The
universal physics of multiscale feedback results from dynamical plasma
physics occurring over temporal and spatial scales that span many orders of
magnitude. We can broadly categorize these regimes into three scales: microscale, mesoscale, and synoptic. Though
each regime encompasses vastly different temporal and spatial scales, the
bidirectional feed-back across the scales is crucial to physical
understanding and, ultimately, prediction. This is true of all
of the physical systems that comprise the sub-disciplines of
heliophysics: solar, heliospheric,
magnetospheric, and Mesosphere, Ionosphere and Thermosphere (MIT).
Understanding the multiscale feedback inherent to plasma dynamics throughout
the helio-sphere requires bridging the gap between kinetic and MHD and
covering several orders of magnitude of time and space. The undersampled mesoscale regime is crucial to study and we
believe could be a unifying focus of heliospheric research in the
coming decades.
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Klein K. G. Spence H. HelioSwarm Team
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HelioSwarm: A Mission to Characterize
Turbulence in Space Plasmas by Leveraging Multi-PointMulti-Scale Observation [#2006]
There
are many fundamental questions about the temporal and spatial structure of
turbulence in space plasmas. Answering these questions is complicated by the
multi-scale nature of the turbulent transfer of mass, momentum, and energy,
with characteristic scales spanning many orders of magnitude. The solar wind
is an ideal environment in which to measure turbulence, but multi-point observations
with spacecraft separations spanning these scales are needed to
simultaneously characterize spatial and temporal structure and cross-scale
couplings.
Recently selected for phase A study
for NASA’s Heliophysics MidEx Announcement of
Opportunity, the HelioSwarm Observatory represents
the opportunity to transform our understanding of the physics of turbulence
in space and astrophysical plasmas by deploying nine spacecraft to measure
the local plasma and magnetic field conditions at many points, with separations
between the spacecraft simultaneously spanning MHD and ion scales. HelioSwarm promises to resolve the transfer and
dissipation of turbulent energy in weakly-collisional magnetized plasmas with
a novel configuration of spacecraft in the near-Earth solar wind and
magnetosphere. These simultaneous multi-point, multi-scale measurements of
space plasmas allow us to reach closure on questions of how energy is
distributed in typical solar wind conditions, as well as in extreme
conditions relevant to astrophysical plasmas.
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Knipp D. J. Verkhoglyadova O. P. Lynch K. A. Morton J.
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Making Full Use of Archival and Future
Magnetosphere-Ionosphere-Thermosphere (MIT) Energy Deposition Data
and Proxies [#2114]
While
anticipating future ground-based resources and space-based missions that
gather data for estimating energy transfer within the near-Earth system, we
strongly advocate for expanded revitalization and re-use of previously
collected data. We tabulate and discuss data collected during the last
several decades that could be used in concert with models, data assimilation
and machine learning methods to build a data cube for contextualizing energy
flow within a few RE of Earth. As an example, we will illustrate low earth
orbit (LEO) Poynting flux that has been derived from revitalized Defense
Meteorological Satellite Program (DMSP)co-measured ion drifts and magnetic
field perturbations. Thinking broadly, we need not limit ourselves to direct
measurements but should consider methods for ‘reverse-engineering’ the LEO
energy state based on rocket measurements, satellite drag and associated
position data. There is a need to advance data processing and analysis
techniques to utilize and cross-calibrate similar measurements, e.g.,
electric field estimates and particle fluxes, across distributed ground and
satellite platforms to optimize use of available datasets. Clever use of data
mining and machine learning with such data could provide historical and
re-analysis views of three-dimensional energy flow in the MIT system. This
effort should encompass particle precipitation and imagery of kinetic energy
deposition, Alfvenic and quasi-steady Poynting vector (electromagnetic energy
transfer), as well as satellite-drag variability data and global navigation
satellite system (GNSS) data. While data revitalization is not without cost,
these types of data potentially provide a historically rich baseline for
re-analysis of energy input under various driving conditions, long-term trends and targets for validating global circulation
models. This historical information could be critical to quickly develop
models for the increasingly congested LEO satellite operation (and debris)
environment. Such models in turn would provide context for future energy-flow
measurements that, while moving toward more distributed platforms, would
benefit from the long-term multi-decade view provided by
historical data.
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Li J.
Bortnik J. An X.
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Generation of Rising-Tone Chorus Waves, Quasiperiodic Emissions, Magnetosonic Waves, and EMIC Waves [#2063]
A
variety of electromagnetic waves grow from space plasma instabilities, and
they play critical roles in redistributing plasma energy. It has been known
for decades that whistler-mode chorus waves typically consist of discrete
rising-tone structures in spectrum as they grow from anisotropic electron
populations. Whistler-mode quasiperiodic emissions also consist of
rising-tone structures with a periodicity of ~10 s - 30 min, and they usually
have a large (up to ~3 Re) spatial scale. Magnetosonic
waves have also been observed to be consisting of rising-tone structures, and
sometimes two groups of rising-tone elements interleave together forming
“zipper-like” magnetosonic waves. EMIC waves that
grow from anisotropic ion distributions have also been observed to exhibit
rising-tone structures. Why all these waves exhibit discrete rising-tone
structures have been poorly understood. Three approaches can possibly address
this question. 1) Run high-resolution Particle-in-cell simulation in a dipole
magnetic field model. 2) Do a comprehensive and statistical study on wave
features and their propagation properties using burst-mode data. 3)
Investigate rising-tone magnetosonic
waves and EMIC waves from ion instabilities, which has not been studied. 4)
Investigate the wave spatial scale and spatial variation using multipoint
measurements with different interspacecraft separations.
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Lieberman R. S. Yudin V. A. Goncharenko L. Harvey V. L. Yue J. France J. Pawson S.
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Upper Atmosphere Reanalysis in the Goddard Earth
Observing System for Space Weather Applications and Support of Heliophysics
Missions (GEOS-H) [#2034]
Extension
of the GEOS-5 global atmosphere model into the
ionosphere-thermosphere-mesosphere (ITM) domain with middle atmosphere data
assimilation (hereafter referred to as GEOS-H) would fully realize NASA’s
research priority of utilizing Earth and Heliophysics mission data for geospace discovery science. Retrospective analysis
(reanalysis) of ITM data in GEOS-H will enhance the scientific return from
previous and current space-borne missions (e. g., UARS, TIMED, MLS EOS Aura,
AIM, GOLD and ICON), and engage future missions such
as the Atmospheric Waves Experiment (AWE), and the proposed Geospace Dynamics Constellation (GDC) and DYNAMIC. We
present the scientific motivation, timeliness, and roadmap for the
development and testing of GEOS-H, and the coordinated community steps needed
to start the retrospective data collection for the upper atmosphere
reanalysis (1992-present).
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Liemohn M. W. Jahn J.-M. Welling D. T. Ilie R.
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Global-Scale Ionospheric Outflow:
Major Processes and Unresolved Problems [#2106]
Outflow
from the ionosphere is a major source of plasma to the magnetosphere. Its
presence, especially that of ions heavier than He+, mass loads the
magnetosphere and changes reconnection rates, current system configurations,
plasma wave excitation and wave-particle interactions. It even impacts the
propagation of information. We present a brief overview of the major
processes and scientific history of this field. There are still major gaps,
however, in our understanding of the global-scale nature of ionospheric
outflow. We discuss these unresolved problems highlighting the leading
questions still outstanding on this topic. First and foremost, since the
measurements of ionospheric outflow have largely come from individual
satellites and sounding rockets, the processes are best known on the local
level, while the spatial distribution of outflow has never been
simultaneously measured on more global scales. The spatial coherence and
correlation of outflow across time and space have not been quantified.
Furthermore, the composition of the outflow is often only measured at a
coarse level of H+, He+, and O+, neglecting other species such as N+ or
molecular ions. However, resolving O+ from N+, as is customary in planetary
research, aids in revealing the physics and altitude dependence of the
energization processes in the ionosphere. Similarly, fine-resolution velocity
space measurements of ionospheric outflow have been limited, yet such
observations can also reveal energization processes driving the outflow. A
final unresolved issue to mention is magnetically conjugate outflow and the
full extent of hemispherically asymmetric outflow
fluxes or fluence. Each of these open questions have substantial
ramifications for magnetospheric physics; their resolution could yield
sweeping changes in our understanding of nonlinear feedback and cross-scale
physical interactions, magnetosphere-ionosphere coupling, and geospace system-level science. A notional mission concept
to resolve these questions of global-scale ionospheric outflow is presented.
This mission would consist of several (4–8) spacecraft at high-inclination
(>80°) orbits in circular trajectories well above the exobase (>1000 km
altitude). The identically-instrumented satellites
should consist of a suite of sensors, including a low-energy ion
spectrometer, auroral particle spectrometer, magnetometer, and perhaps also
an auroral camera and GPS receiver for remote sensing observations.
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Matsuo T. Goncharenko L. Paxton L. Yee S. Oberheide J. Liu H.
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DYNAMIC — A Mission Concept to Transform the
Climatological Picture of the Ionosphere and Thermosphere into its Weather
and Beyond [#2161]
A Dynamical
Neutral Atmosphere-Ionosphere Coupling (DYNAMIC) STP mission concept was
originally put forth as the 2013 Decadal Survey’s
Atmosphere-Ionosphere-Magnetosphere-Interaction Panel’s number one priority.
DYNAMIC’s goal is to reveal how terrestrial weather drives ionosphere and
thermosphere space weather by providing key observations for transforming the
climatological picture of the ionosphere and thermosphere into its weather.
The community now has an opportunity to pursue DYNAMIC science with a small,
cost-effective mission launched as a rideshare secondary payload concurrent
with GDC’s launch. To address the DYNAMIC goals and to fully understand lower
atmosphere influences on the ionosphere-thermosphere system, the height
evolution of the wave spectrum throughout the thermosphere needs to be
investigated on global scales. This will require measurements of day and
nighttime wind and temperature throughout the thermosphere, even under the
presence of aurora. Measurements of ion and neutral compositions are also
required to quantify ion-neutral interaction and dynamo processes in order to understanding how lower-atmosphere influences
manifest in the ionosphere. The instruments that can provide these critical
measurements can also provide key observations needed to determine the
fundamental turbulent mixing processes that take place in the lower
thermosphere impacting global ionospheric structure, exospheric temperature and atmospheric escape relevant to the
evolution of the planetary atmosphere. DYNAMIC measurements, in combination
with GDC measurements, can also uncover the ionosphere-thermosphere’s active
role in its coupling with the magnetosphere by quantifying Joule heating
induced by wind dynamo, fly-wheel effects, and horizontal gradients in
conductance. The poster gives an overview of broad science areas that can be
pursued with DYNAMIC as a SMEX-lite mission and discusses what innovation and
community engagement involving the ground-based community would be required in order to seize this opportunity.
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Matsuo T.
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Predictability of the Space-Atmosphere Interaction Region (SAIR) [#2165]
The
Space Atmosphere Interface Region (SAIR), encompassing the ionosphere and
thermosphere, is the intersection between the Earth’s neutral atmosphere and
the Sun’s fully ionized atmosphere, simultaneously exposed to dynamic drivers
from both space and terrestrial weather. The SAIR, as the interface to space,
controls the escape of gas into space. Understanding the intrinsic
predictability of the SAIR, as the upper atmospheric state constantly shifts
from one dynamic equilibrium to another in response to highly variable
drivers, is a fundamental science question in Heliophysics. The Earth’s
atmosphere is a nonlinear deterministic dynamical system. The Navier-Stokes fluid equations, when used for modeling troposphere
dynamics, indicate that this dynamical system exhibits considerable chaotic
divergence resulting from high sensitivity to initial conditions. The
physical insight that the predictability of tropospheric weather is highly
dependent on the details of initial conditions, supported by the
deterministic chaos theory, has guided the development of sophisticated
tropospheric numerical weather prediction systems. Yet those same Navier-Stokes equations when applied and isolated to the
thermosphere appear stable, leading to reproducible predictable dynamical
behaviors controlled largely by the details of external forcing. The
thermosphere, however, is not an isolated system, so even though it may not
be inherently chaotic, there are pathways connecting and linking the
thermosphere to its surrounding regions, which give rise to nonlinearity that
likely limits the predictability. Furthermore, as a forced-dissipative
dynamical system, the SAIR’s predictability is highly dependent on details of
the dissipation processes as well as forcing. Vertically propagating
atmospheric waves from the lower atmosphere are dissipated and transformed on
their way through the SAIR. This wave dissipation process manifests as
turbulence often parameterized as “eddy diffusion” in models, which is a
poorly understood fundamental SAIR process that can impact global ionospheric
structure, exospheric temperature and atmospheric
escape relevant to the evolution of the planetary atmosphere. The poster gives
an overview of outstanding scientific questions pertaining to the SAIR’s
predictability and discusses predictability as a useful framework to test of
our scientific understanding of the
Ionosphere-Thermosphere-Mesosphere system.
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Nykyri K. Ma X. Burkholder B. Fuselier S. Wing S. Broll J. Ganjushkina N. Wilder R. Sibeck D.
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Cross-Scale Plasma Science in Super- and Sub-Magnetosonic Plasma Regimes [#2166]
Space
plasmas are highly collisionless and involve
several temporal and spatial scales. Due to experimental and computational
limitations, understanding the physical mechanisms responsible for energy
transport between these scales is a challenge. In this poster we discuss
major unresolved questions in super– and sub-magnetosonic
plasma regimes in the solar wind and Earth’s magnetosphere and how these
questions can be only resolved via next-generation constellation missions
covering simultaneously CME, fluid, ion, and electron scales as well as next
generation computational models capable of ingesting new data in
near real-time.
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Oberheide J. Lu X.
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Making the Step from Tidal Climate to Tidal Weather — Connecting
Meteorology with Space Weather [#2050]
The
height evolution of the global-scale wave spectrum between the mesosphere and
upper thermosphere remains an unsolved problem due to the lack of continuous
day-and nighttime temperature and wind observations throughout the whole
thermosphere. A particular challenge is the lack of E-region data in the
transition region into the diffusive regime and the lack of high and
mid-latitude observations around 200 km where ion drag is predicted to be an
important wave source that is yet to be explored. Meteorological weather
events such as polar vortex deformations, the Madden-Julian Oscillation, and
others dramatically change the global-scale wave variability in the E-region
dynamo on time scales that can only be resolved by satellite constellations
measuring at multiple local times each day. The poster overviews the current
state of knowledge of tidal “weather”, what is not known, and what
measurements are needed to make progress in explaining ionospheric
variability driven by the combined effects of tides and planetary waves from
the lower atmosphere.
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Ogasawara K. Burleigh M. Chornay D. J. Collier M. R. George D. E. Goldstein J. Hirsh M. Hwang K.-J. Liemohn M. W. Madanian H. Nocolaou G. Nishimura Y. Schunk R. W. Semeter J. L. Zesta E. Zettergren M.
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Importance of Ion Velocity Distribution Function
Observations in the Ionosphere [#2112]
Precise
observations of multi-species flows and non-Maxwellian velocity distribution
functions (VDFs) are key to understanding the
atmosphere-ionosphere-magnetosphere (AIM) coupling processes. However,
mass-resolved ion VDF observations are extremely rare in the ionosphere; only
a limited amount of satellite and sounding rocket data exists, since past and
currently existing instruments have technical difficulty resolving the ion
properties sufficiently. In this presentation, we discuss the importance of
such observations in the next decades in Heliophysics community.
Quantitative measurements of flow vectors for all co-existing plasmas are
essential to determine the total energy and mass content in the flow and the
threshold of instabilities and resulting heating, turbulence, and anomalous
resistivity in the ionosphere. Inhomogeneity in flow channels can create free
energy by producing perpendicular electric fields and causing plasma heating
through instability and wave excitation. Ionospheric plasma VDFs frequently
show non-thermal features. Frictional heating from relative velocities
between drifting ions and neutrals produces specific, non-thermal VDFs
depending on mass. These ion VDFs are studied by past theoretical and
numerical predictions, and are predicted to evolve
depending on the relative speed and mass ratio between ions and neutrals.
Another mechanism is the resonant heating with waves. In the wave resonance
process, pronounced mass-dependent transverse heating becomes evident as a
noticeable asymmetry in VDFs.
Accurate observations of the mass-resolved ion flow structure and the
ion 3-d VDFs throughout heating processes in the ionosphere will have a huge
impact to the Heliophysics community by providing missing pieces to
understand the AIM coupling mechanisms, and redistribution of energy during
space weather events. For example, the ion upwelling motion can be initiated
by the anisotropic VDFs, and are thought to be the
source of the ion outflows which supply the cold ionospheric plasmas into
magnetosphere and regulates the physical processes. A comprehensive
understanding of the ion outflow is also important to understand the
evolution of the atmosphere. Moreover, the investigation proposed here has
significant impacts in two active and critical areas for current/future
Heliophysics research: numerical
modeling and ground-based observations.
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Ozturk D. S. Garcia-Sage K. Kim Connor H. Lin D. Merkin V. G. Zheng Y. Chen M. W. Zou S. Halford A. Weimer D. Crowley G. McGranaghan R.
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A Collaborative Approach to Understanding Auroral Region
Magnetosphere-Ionosphere-Thermosphere Coupling Through
Ionospheric Conductivity [#2059]
The
ionospheric conductivity modulates the magnetosphere’s response to the solar
wind, by affecting the ionospheric convection and field-aligned current (FAC)
patterns. To gain a predictive understanding of the
Magnetosphere-Ionosphere-Thermosphere (MIT) systems, it is necessary to treat
ionospheric conductivity in an accurate and self-consistent way. By 2050 the
improvements in modelling and observations, combined with the strength of
collaborations in our field, should enable the global specification of 3D
conductivities, with quantified uncertainties. The improving efficiency of
high-performance computing (high-resolution, kinetic modelling, etc.) and
data-informed models (data assimilation, AI, etc.), as well as the increasing
availability of measurements, will be very advantageous for advancing the current
operational tools.
The characterization of ionospheric
conductivity at the auroral region is a particularly difficult task because
of the various multi-scale drivers that factor into its determination and the
lack of in-situ data. The specification of these drivers is also challenging
due to a lack of measurements, limited data coverage, insufficient spatial
and temporal resolutions, and physical assumptions used in numerical models.
Therefore, a wide collaborative approach is needed to fully comprehend the
key role ionospheric conductivity plays on the MIT system and how it is
influenced by different drivers.
Based on the discussions that took
place in the NSF Geospace Environment Modelling
Ionospheric Conductance Challenge session, the following science
investigations are deemed necessary by the community to predict the
conductivity and to quantify the related uncertainties:
1.Investigating the ionospheric
conductance and conductivity changes due to different auroral precipitation
patterns.
2.Investigating the relationship
between the conductivity and the characteristics of the neutral population.
3.Investigating the ionospheric
conductivity at different spatial and temporal scales.
These science investigations can be achieved by (i) establishing a universal
ground-truth data set, (ii) developing model validation, verification, and
uncertainty quantification tools, (iii) developing physics-based local and
global models of conductance/conductivity, (iv) improving empirical,
numerical, and data assimilation models, (v) forming new collaborations,
working groups, and teams, and (vi) organizing coordinated measurement and
modelling efforts.
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Paxton L. J. Zhang Y. Kil H. Schaefer R.
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Using Remote Sensing from Space to Explore
the Ionosphere/Thermosphere [#2127]
FUV
remote sensing, particularly using a sensor like the Global Ultraviolet
Imager (GUVI) on the NASA TIMED mission or the SSUSI instrument on the DMSP
satellites, enables us to discover the connections within the
ionosphere/thermosphere that lead to meaningful tests of our physical
understanding via comparison with models.
GUVI and SSUSI have shown that, with 1990s’ technology, one sensor can
image the aurora (producing conductivity, Eo, and Q
maps), dayside neutral density altitude profiles (O, N2, O2, NO, H), dayside
and nightside O+ profiles, dayside temperature (Texo
and N2 rotational temperatures), and map ionospheric bubbles as well as
continue the O/N2 maps we have provided for almost 20 years - with every
orbit it makes.
The next generation instruments developed under the SSUSI-Lite and
SIHLA programs have greater flexibility and capability.
These sensors enable us to provide a 3D understanding of the I/T
system. Some of the science questions are straightforward: How does the observed behavior of the I/T
compare from solar cycle (SC)23 to SC24 to SC25 and beyond? Others require
additional information, especially from the ground-based community: What role
does the asymmetric energy inputs (between Northern and Southern hemisphere)
play in the response to solar/geomagnetic inputs? What role does forcing from below play in determining and modulating the
I/T response and behavior? Has the behavior of the upper atmosphere changed
due to anthropogenic change in the troposphere? There are other questions
about the observed smaller scale behavior (e.g.
TADs, TIDs, bubbles, blobs and irregularities) that can be studied with this
next generation tool. And many others...
Flying these low-cost, powerful sensors opens new opportunities for
the community.
We argue that I/T research would benefit from a commitment to provide
long-term sensors of this time for open use by the community.
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Perri S. Perrone D. Roberts O. Settino A. Yordanova E. Sorriso-Valvo L. Veltri P. Valentini F.
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Detection of Electrostatic Waves in the Earth’s Magnetosheath [#2101]
The
high cadence plasma, electric, and magnetic field measurements by the
Magnetospheric MultiScale (MMS) spacecraft allow us
to explore the near-Earth space plasma with an unprecedented time and spatial
resolution, resolving electron-scale structures that naturally emerge from
plasma complex dynamics. The formation of small-scale turbulent features is
often associated to structured, non-Maxwellian particle velocity distribution
functions that are not at thermodynamic equilibrium. Using high-resolution
measurements in the Earth’s magnetosheath, we
analyze regions characterized by bumps in the power spectral density of the
parallel electric field at sub-ion scales. In such regions, ion velocity
distribution functions exhibit beam-like features at nearly the local ion
thermal speed. Ion cyclotron waves in the ion-scale range are frequently
observed at the same locations.
These observations, supported by
Hybrid Vlasov-Maxwell numerical simulations, are
consistent with the generation of ion-bulk waves that propagate at the ion
thermal speed. This represents a new branch of efficient energy transfer
towards small scales, which may be relevant to weakly collisional
astrophysical plasmas.
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Pfaff R. Rowland D. Kepko L.
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Understanding the Earth’s Atmosphere-Space
Transition Region [#2098]
The
Earth’s Atmosphere-Space Transition Region Explorer is a poorly understood
yet vital region of Geospace — it is here where the
Earth’s atmosphere and the ionized gases of space interact within a “boundary
layer” at the base of the ionosphere between 100-250 km altitude. The
interactions of these co-existing gases within this region and their
consequences are profound. It is here is where magnetospheric currents close,
where ions and electrons drift at different speeds and directions due to the
influence of ion-neutral collisions, where frictional heating between the
gases is significant, where neutral wind “jets” are set up in concert with
enhanced auroral conductivity, and where gravity waves propagating from below
break and deposit energy. Furthermore, at high latitudes, this region is at
the end of the line of the sun-upper atmosphere chain, and thus harbors the
critical missing link in our knowledge of the transfer, dissipation, and
regulation of energy and momentum from the Sun to the upper atmosphere.
Understanding the earth’s transition region is highly synergistic with NASA
and NSF goals that seek to understand not only ion-neutral coupling processes
but also how solar wind driven sources of energy and momentum couple with the
upper atmospheres of the earth and those of other planets. Indeed, low
altitude measurements on NASA’s MAVEN satellite have revolutionized our
understanding of the martian ionosphere-thermosphere system and we can expect
equally ground-breaking results from future measurements within the Earth’s
transition region as well.
To make progress with our understanding, we discuss the need for high time
and spatial resolution measurements of key parameters in order to reveal the
true nature of the characteristics and energy exchange within the
atmosphere-space transition region. Ultimately, the science motivation must
lead to new mission designs and creative data acquisition strategies.
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Qin M. Q. Li W. L. Ma Q. M. Woodger L. W. Millan R. M. Shen X. S. Luisa L. S.
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Energetic Electron Precipitation Modulated by Whistler-Mode Waves [#2118]
Energetic
electron precipitation modulated on the Ultra-Low-Frequency (ULF) wave
timescale has been shown in some previous observations, but it remains to be
established whether ULF waves are directly responsible for the electron
precipitation or act as a complementary role in driving electron precipitation.
In this work, we present simultaneous multi-point observations of waves
observed by both Van Allen Probes, associated with conjugated energetic
electron precipitation by BARREL and POES-18 at around L~ 6 from noon to
dusk. We show that the correlation coefficient between whistler-mode waves
and electron precipitation is high in several regions, including plumes and
plasma trough. An almost one-to-one correlation is observed between
whistler-mode waves and energetic electron precipitation. ULF wave
fluctuation shows a similar period to whistler-mode wave modulation but the
correlation between them is low. Some whistler-mode wave intensification is
associated with plasma density enhancement. We further quantify electron
precipitation using theory and modeling based on the observed wave and plasma
parameters to evaluate the accurate role of ULF waves and whistler-mode waves
in energetic electron precipitation.
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Rowland D. E. Halford A. Klenzing J. Oliveira D. Paxton L. Turner D. Verkhodglyodova O.
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Cross-Scale and Cross-Regime Coupling in the
ITM: Studying Weather, not just
Climate, in the Middle and Upper Atmosphere [#2146]
The
middle and upper atmosphere is rich in dynamics at scales from tens of meters
to tens of thousands of kilometers and timescales ranging from seconds to
solar cycles. Our understanding of the mechanisms at work that drive neutral
and ionized phenomena is inherently biased towards the very small / very fast
scale or to the very large / very slow scales. This microphysics /
climatological view, which has come about in the context of sparse
observations, creates knowledge gaps in several key physics areas: 1) Critical meso-scale phenomena that take
place on timescales from tens of minutes to several days and spatial scales
from hundreds of kilometers to thousands of kilometers; 2) Cross-scale
coupling, in both directions, as small-scale features provide local energy
dissipation and momentum transfer, feeding back on large-scale features which
transport energy, mass, and momentum, and which set the stage for smaller
scale instabilities and processes; 3) Cross-regime coupling, between the
neutral and ionized gases of the middle and upper atmosphere (including
across magnetic field or along magnetic field lines), and between the
collisional and collisionless plasmas of the
ionosphere and magnetosphere.
These sparse observations will be extended, by the Geospace
Dynamics Constellation (GDC) and DYNAMIC missions, which will provide
critical surveys of the upper atmosphere. Despite the groundbreaking nature
of these missions, many questions will remain.
In particular, these missions will not provide the
observations needed to understand how the ITM system varies at medium to
large scale on timescales of minutes to days. Open questions that must be
answered in the next decades, and with missions beyond GDC and DYNAMIC
include: a) How does lower atmospheric
forcing of the middle and upper atmosphere, on horizontal scales greater than
~1000 km, vary on day and sub-day timescales? b) What is the contribution of
small-scale structures and cross-scale coupling to large-scale energy and
momentum budgets, in the middle and upper atmosphere? c) What are the
time-varying two-way electrodynamic linkages between the ionosphere and
magnetosphere, and how are these reflected in field-aligned and ionospheric
currents on scales from auroral arcs to global?
Answering these questions will require dense observations of a variety of
physical parameters, and will lead to true “meteorological” understanding of
the middle and upper atmosphere.
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Sarris T. E. Daedalus Team
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Daedalus: A Mission Concept to
Explore the Lower Thermosphere-Ionosphere [#2062]
Daedalus
is a mission concept that has recently completed Phase-0 studies within ESA’s
Earth Observation Explorer programme. It targets
the lower thermosphere and ionosphere (LTI) between 100 and 200 km, where the
atmosphere transitions from well-mixed and electrically neutral, to
heterogeneous and partly ionised, staging a host of
complex processes related to the interactions between neutral and charged
constituents. It tackles fundamental, long-standing questions on processes
governing LTI energetics, dynamics and chemistry,
marred by a scarcity of available measurements and large uncertainties in
existing models.
Specific objectives include
detailed estimates of the frictional heating in the LTI resulting from the
electro-magnetic connection to space as well as from energetic particle
precipitation (EPP); a thorough characterisation of
the fluxes of EPP that pass through the LTI and affect the middle atmosphere;
retrieving altitude-resolved estimates of the electro-magnetic forcing as
well as of the forcing due to changes and gradients in densities and
temperatures; determining the response in the LTI to upward propagating
atmospheric waves, disturbances, and other dynamic features; and establishing
the range of parameters that trigger radio wave-disturbing irregularities.
An overarching goal is to help
develop system-level understanding of the whole Earth system, addressing an often overlooked link in Earth system science: the connection of the atmosphere to space.
This brings together atmosphere and space scientists and crosses traditional
boundaries of science and applications, from traditional space physics over
whole atmosphere and Earth system model development to climate research and
space weather.
Daedalus targets in-situ, simultaneous,s and co-located measurements of all
relevant parameters for neutrals, plasma, energetic particles, and fields,
systematically extending data sets first gathered by NASA’s Atmosphere
Explorers in the 1970s. Probing the LTI calls for challenging measurements by
spacecraft in elliptical orbits with altitude perigees around 150 km and
below during specific incursions, gathering measurements through the
ionosphere’s F- and E-regions with each pass, whilst ensuring adequate
coverage in latitude, local time, and altitude.
This poster gives an overview of
the pursued scientific objectives, critical requirements, the modelling
approaches used to define and assess them, and first elements of the mission
profile.
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Volz R. Erickson P. J. Palo S. E. Chau J. L. Vierinen J. Swoboda J.
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A Global Radio Remote Sensing Network for
Observing Upper-Atmospheric Dynamics [#2138]
Our
current sampling of the upper atmosphere is wholly insufficient to measure
the highly variable (both in space and time) processes therein and make
predictions on par with lower atmospheric weather. Progress on key scientific
topics noted in other Heliophysics 2050 posters and white papers, such as
forcing from the lower atmosphere and whole-atmosphere coupling, is hindered
by poor local time coverage and severe undersampling
of mesoscale structures. Ground-based observations complement space-based
measurements through their unique views of the upper atmosphere. Regular, densely-sampled measurements, even if they lack the
precision of those from our flagship instruments, would be a boon to
scientific understanding and modeling of the geospace
system. These ideas are not new, but we posit that the technology has now
arrived to make dense ground-based observations of the upper atmosphere
feasible in cost and effort. We highlight two of the key
enabling technologies here, although we note that other techniques and
instruments can play a large role in providing complementary measurements.
1) MIMO meteor radar, measuring the MLT wind field: Recent developments in multiple-input
multiple-output (MIMO) meteor radar networks have made higher-resolution wind
measurements of the upper atmosphere possible. These networks operate over
coded continuous-wave links between separately-located
transmitter and receiver sites to increase the density of specular meteor
trail observations and provide diversity in sensing Doppler-derived wind
projections. Such datasets contain enough information to estimate the
three-dimensional wind field within the observation volume to a resolution
limited only by the measurement density in space and time.
2) Low-power ionosonde, measuring bottomside
ionospheric density: Coded continuous-wave transmissions also enable a
cross-linked network of low-power ionosondes operating in much the same
manner as the above-described MIMO meteor radar network. Each transmitter and
receiver pair can be used to produce an oblique ionogram.
With combinatorial scaling, this provides a cost-effective way to densely
sample the ionospheric density along each TX-RX link. Innovations such as the
electro-magnetic vector sensor (6 orthogonal antenna elements with a common
phase center) could help to increase each individual instrument’s degrees of
freedom further. This could lead to volumetric imaging of the bottom side
ionosphere within the regional network.
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Xu Z.
Hartinger M. H. Kim H. Welling D. Ozturk D. Weygand J. Oliveira D. Noh S. Shi X. Kuzichev I. Edwards T. Salzano M. Lessard M. Weimer D. Baker J. Clauer C. R.
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Causes and Consequences of Interhemispheric Asymmetries in the
Magnetosphere — Ionosphere System [#2032]
In the
Earth’s Magnetosphere-Ionosphere (MI) system, both northern and southern
upper atmospheric regions are linked to the magnetosphere through magnetic
fields. The interhemispheric asymmetries in these regions are shown in
observational and modeling studies with various signatures, such as magnetic
pulsations, ion outflows, field-aligned currents, auroral particle
precipitation, etc. These asymmetries evolve from geographic and/or
geomagnetic aspects of Earth (dipole tilt and dipole), as well as possible
effects that arise directly from solar wind, interplanetary magnetic fields,
solar illumination, asymmetric inputs from lower atmosphere, etc.
It is crucial to understand how each source of asymmetry interacts with each
other and how asymmetric structures incorporate this information into
predictive models. In the past, since there were sparse data points in the
southern hemisphere, it was often oversimplified that the understanding of
one hemisphere can be simply mapped to the other. This assumption does not
address the discrepancy found in observations and models. The MI coupling
processes associated with the solar energy input and geospace
feedback can be misestimated due to asymmetries. Individual studies of
asymmetries in isolation lack the capability to reveal the causes of
underlying asymmetric processes; models are often not capable of adapting
multiple asymmetric mechanisms simultaneously.
Looking forward to 2050, better understanding the causes and effects of
asymmetries in MI coupling could be achieved by: 1) Identifying the spatiotemporal
characteristics and magnitudes of interhemispheric asymmetries by utilizing
data from spacecraft and ground-based instruments in both hemispheres, such
as field and particle data from spacecraft in solar wind and magnetosphere,
magnetic field and plasma drift data from ground magnetometers and radars at
conjugate locations; 2) Investigating the relative contributions of each
driver by using statistical surveys (dB/dt maps, MIEs, ULF waves...) and
timing analysis (solar wind and IMF conditions, ionospheric convection,
auroral precipitation...); 3) Using the observational results to guide and
validate models, and conducting idealized studies with controlled external
drivers. The experiments may include various solar wind and IMF conditions,
seasonal effects, and conductivity estimates. It will enable characterization
and quantification of external drivers on interhemispheric asymmetries.
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Zhang S. R.
Erickson P. J.
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Storm-Time Dynamic Magnetosphere-Ionosphere-Thermosphere Coupling at Subauroral Latitudes [#2097]
The upper atmosphere at mid-
and subauroral latitudes lies within the
plasmasphere boundary layer (as named by Carpenter and Lemaire). This
boundary layer forms the interface between high latitudes, open to
substantial deposition of solar wind and magnetosphere energy, momentum and
particles, and low latitudes, containing the highest plasma density in
Earth’s ionosphere. Due to this overlap between cold dense plasma and hot
tenuous plasma, mid-latitude regions are rarely in a fully stable, quiet
state due to constant forcing from both above and below. When considering
adverse space weather impacts, this region is among the most densely
populated on the planet, with a wide deployment of technology and systems
with large importance to human life. For these reasons, to advance
state-of-the-art knowledge on the upper atmospheric system, we believe future
midlatitude geospace science is essential and will
need to address particular challenges provided by storm-time conditions.
Challenges posed by storm-time mid-latitude ionospheric dynamics concern the
unique role of the mid-latitude ionosphere and thermosphere in pathways of
(a) energy and momentum transfer from high latitudes into low and equatorial
latitudes (through for example traveling atmosphere/ionosphere disturbances,
disturbance wind dynamo, O/N2 changes), (b) horizontal plasma transport into
high latitudes (Storm Enhanced Density, Tongues of Ionization, and polar cap
patches) and vertical transport into the plasmasphere and magnetosphere (as
ion upflow/outflow), and (c) direct vertical
coupling through electrodynamics and energetics within the midlatitude
system, influencing known magnetosphere/ionosphere/plasmasphere effects such
as plasmaspheric erosion / refilling, the Subauroral Polarization Stream, ion-neutral coupling, and
ionospheric irregularities. Although these aggregate pathways for
mid-latitude momentum and energy exchange have been studied in previous
literature, they have seldom been treated in a systematic, interactive, and
self-consistent manner. Characterization of these pathways and physical
processes in 3-D spatial structure combined with time scales spanning seconds
to years, remains extremely limited. Ultimately, future joint modeling and
observational studies, both statistical and event-based, still require
considerable community effort for adequate specification and proper forecast
of dynamic spatiotemporal variability of the mid-latitude upper atmosphere.
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Authors
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Poster Title and Abstract
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Bhardwaj S. Purohit P. K.
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Distribution and Association of Geomagnetic
Storms with Properties of Halo CMEs [#2058]
We have
studied the distribution and association of geomagnetic storms of different
intensities with over the different ranges of three kinds of properties of
halo CMEs. We have selected the halo CMEs that were observed during the solar
cycle 23. Then we identified the geomagnetic storms associated with each of
the selected CMEs. The geomagnetic storms were divided into three categories on the basis of the Dst value,
as weak (Dst > –50 nT),
moderate (–100nT<Dst ≤ –50 nT) and intense (Dst ≤
–100 nT). We selected the three properties of the
selected CMEs viz. speed, acceleration and transit
time. We constructed several ranges of these CMEs properties and investigated
the distribution and association of three different kinds of geomagnetic
storms over these different ranges of CME property ranges. We found that 60%
of geomagnetic storms occur in the range of 500–1500 km/s category of CME
speed. Similarly, 55% storms are distributed over the range of 25–75 hours
category of transit time while 66% storms occur in the range of 0–30 m/s2
category of positive acceleration and 78% storms occur in the range of 0–20
m/s2 category of negative acceleration. Moreover, it was found more number of storms is associated with negative
acceleration. In negative acceleration categories the highest occurrences
were of intense storms while in the positive acceleration categories the
highest occurrences were either of weak storms or moderate storms.
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Brandt P. C. Provornikova E. Mostafavi P. DeMajistre R. Turner D. Lisse C. Krimigis S. M. McNutt R. L. Jr Wimmer-Schweingruber R. Roelof E. C. Runyon K. D. Rymer A. Mandt K. Blanc M. Hill M. E. Alkalai L. Alterman B. Baker D. N. Bale S. Baliukin I. Barabash S. Bertaux J. -L. Beichman C. Bladek P. Bzowski M. Cahill J. Clarke J. Christian E. Cooper J. Decker R. Desai M. Dialynas K. Elliott H. Eriksson S. Fedorov A. Frisch P. Funsten H. O. Fuselier S. Galli A. Gladstone R. Gurnett D. Gloeckler G. Gruntman M. Horanyi M. Izmodenov V. Kempf S. Katushkina O. Kozanecki M. Kurth W. Ratkiewicz R. Lallement R. Lavraud B. Linsky J. Livi S. Liewer P. Mayyasi M. Mewaldt R. Mikolajkow T. Mis T. A. Mitchell D. G. Moebius E. Nicolau G. Nikoukar R. Opher M. Park J. -W. Paschalidis N. Paxton L. Pogorelov N. Poppe A. Quemerais E. Redfield S. Reisenfeld D. B. Richardson J. D. Retherford K. Schwadron N. Sokol J. M. Sterken V. Stern A. Szabo A. Szalay J. R. Tkacz A. Wicks R. Wang C. Wood B. Wurz P. Zank G. Zemcov M. Zarka P. Zong Q.
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Expanding the Realm of Solar and Space Physics: Exploration of the Outer Heliosphere and
Local Interstellar Medium [#2119]
Our
Star and its protective heliosphere are one of hundred billion stars and
astrospheres in the galaxy that plow through the vast interstellar medium
made up of the material from supernova remnants. During its evolution, the
Sun has completed about twenty revolutions around the galactic core and has
encountered widely different environments that have all helped formed the
system we live in. The amount of interstellar plasma, gas, dust
and galactic cosmic rays within the heliosphere have been dictated by the
unique interaction mechanisms at the boundary that today represent one of the
most outstanding problems in space physics. Heliophysics (or Solar and Space
Physics) is a unique scientific discipline that has brought us, robotically,
to the farthest reaches of space. The Voyager spacecraft will soon cease
operations on the doorstep of interstellar space (~170 AU) and has unraveled
a remarkable new regime of space physics. Remote observations from within the
Heliosphere by IBEX and Cassini have revealed global features from the
heliospheric boundary region that are still seeking explanations. Telescope
measurements of absorption spectra have discovered that our Sun is about to
leave the Local Interstellar Cloud and entering a completely different
environment of interstellar space. All these discoveries amplify that, as our
Sun is critical to the formation of our system and life, its interaction with
the ever-changing interstellar medium is an integral part of understanding
the dynamic heliosphere and conditions within it, that represents the largest
gap of heliophysics today. The historic science discoveries are completely
enabled by exploring a new region of space in the range of 400–1000 AU. This
region is now made accessible through the increasing availability of large
launch vehicles within realistic mission design lifetimes. The quest of
heliophysics is therefore inevitably expanding from understanding our
habitable bubble to also include the interaction with the surrounding
interstellar medium to ultimately understand how the solar journey through
the milky way has formed our home in the galaxy and where we are going.
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Dialynas K. Krimigis S. M. Decker R. B. Mitchell D. G. Roelof E. C. Brandt P. C. Burlaga L. Della Torre S. DeMajistre R. Galli A. Gkioulidou M. Hill M. E. Kornbleuth M. Kurth W. McNutt R. Mostafavi P. S. Nikoukar R. Opher M. Powell E. Provornikova E. Rancoita P. G. Richardson J. D. Roussos E. La Vacca G. Westlake J.
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The Dynamic Heliosphere and Its Interaction with
the LISM: Open Questions and
Future Perspectives [#2042]
The V1
and V2 crossings of the TS in 2004 (~94 AU) and 2007 (~84 AU), respectively,
led to the first measurements of the ions and electrons that constitute the heliosheath (HS), between the TS and the HP. The Voyager
crossings of the HP, in 2012 (~122 AU) and 2018 (~119 AU), respectively,
pinpointed the extent of the heliosphere’s expansion into the LISM. Both
crossings were associated with a depletion of particles of solar origin and
an abrupt increase of GCR intensities, magnetic field
and plasma density. The LISM temperature was somewhat higher than expected.
Apart from the similarities between the V1 and V2 crossings, some substantial
differences were also identified. For example, the V1 crossing of the HP was
associated with the discovery of a flow stagnation region that was observed
before the boundary, possibly due to flux tube interchange instability at the
HP. The Voyager in situ measurements were complemented by global ENA images
from IBEX at ~1 AU (<6 keV) and Cassini/INCA at ~10 AU (5.2–55 keV),
revealing a number of previously unanticipated heliospheric structures such
as the “Ribbon,” a bright and narrow stripe of ENA
emissions that is thought to lie beyond the HP and “sits” on top of the
Globally Distributed Flux, and the “Belt”, a broad band of emission in the
sky, identified as a high intensity, relatively wide and nearly energy
independent ENA region (>5.2keV range), that wraps around the sky sphere
in ecliptic coordinates, that corresponds to a “reservoir” of particles that
exist within the HS, constantly replenished by new particles from the solar
wind (SW). In anticipation of the IMAP mission at ~1 AU (expected launch in
2024), and the Interstellar Probe mission (>2030), this poster lists three
open science questions that can only be answered by exploiting a combination
of in-situ ion measurements and remotely sensed ENAs: 1) Where are the heliosphere boundaries and
how thick is the HS? 2) Is there a “missing” pressure component effecting the
dynamics of the global HS and its interaction with the LISM? 3) Why is the
shape and size of the global heliosphere different when looking in different
ENA energies? Finally, we provide a brief description of the particle and
fields measurements needed to address these questions.
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Dikpati M. Leamon R. J. Anderson J. L. Belucz B. Biesecker D. Bothun G. Fan Y. Gilman P. A. Guerrero G. Hoeksema J. T. Kitiashvili I. N. Kosovichev A. G. Linkmann M. McIntosh S. W. Norton A. A. Rempel M. Tripathy S. C. Upton L. Wang H. Wing S.
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Space Weather Modeling and Prediction for Intermediate Time-Scales [#2145]
“Space
Weather” describes the conditions in the terrestrial system, particularly on
its outer envelope, that can affect various ground- and space-borne
technologies due to the impact of energetic particles and magnetic fields
streaming from the Sun. This could occur either due to the continuous flow of
solar wind or due to the onset of CMEs or flares in a short interval of time.
While the chain of processes involved in transmitting the adverse, hazardous
effects of these energetic particles into the Earth’s atmosphere is extremely
complex, over the past several years considerable effort has been undertaken
to understand and predict space weather on time-scales
from a few minutes-to-hours up to a few days. Also, studies to understand the
effects of adverse solar events occurring on longer time-scales
from decades to centuries, on society’s space-weather-sensitive instruments,
industries, national security systems have continued for many years. In
addition to very short (hours-to-days) and much longer (decadal to
millennial) time scales where solar events could arise, there is an important
intermediate time scale, the interval from weeks-to-months, over which solar
activity varies strongly. These events are often called ‘quasi-annual’ or
‘seasonal’ variability, during which an enhanced burst of solar activity is
followed by a relatively quiet interval. The strongest space weather events
happen during the “bursty seasons”. Therefore,
understanding the origins of and predicting major space weather events on time-scales from weeks to months ahead, has significant
scientific and economic value. This ‘intermediate’ time-scale
would also fill-in the gap between the short and longer time-scale forecasts
of space weather. Recently it is shown that solar Rossby waves play crucial
roles in simulating enhanced solar activity bursts weeks to months ahead. In
turn, these will allow us to anticipate major space weather events well ahead
of time, since they are closely tied to these bursty
‘seasons’. Details can be found in our white paper.
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Ehresmann B. Hassler D. M. Zeitlin C. Guo J. Wimmer-Schweingruber R. F. von Forstner J. Matthiae D. Berger T. Reitz G.
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Space Weather and Radiation Measurements on the
Martian Surface with MSL/RAD Throughout the Solar Cycle [#2144]
Exposure
to radiation remains one of the major risks for the human exploration of
space, the moon, and Mars. To protect human explorers from potential health
hazards, the Martian radiation field and how space weather affects it must be
assessed in detail. The Mars Science Laboratory (MSL) Radiation Assessment
Detector (RAD) has been conducting radiation measurements on Mars since
August 2012, collecting data from near the (weak) maximum to the deep minimum
of solar cycle 24 and beyond. While changes in the Martian radiation field
are mainly driven by solar modulation of the galactic cosmic radiation, on
short time scales the radiation field can be dominated by large Solar
Particle Events (SPEs) which can increase the surface radiation dose by
orders of magnitude. As large SPEs can be seen throughout the solar cycle,
these extreme space weather conditions must be characterized not only at
solar maximum, when large CMEs and SPEs are more likely to occur, but also
during solar minimum. In particular since extreme
variations in the past 2 solar cycles have shown that current models lack
sufficient predictive capability. A continued program of synoptic space
weather observations at Mars is important to characterize extreme conditions
throughout the solar cycle, and from one cycle to the next. Such observations
increase the longitudinal extent of our data base of CMEs and SPEs and help
improve models and understanding of the 3-D structure and propagation of such
events. To support human exploration to Mars and beyond, heliosphere-wide
space weather monitoring, prediction and early warning for these missions
needs to be provided. We present RAD measurements throughout the solar cycle,
show how the solar cycle affects the radiation environment on Mars, and
discuss implications for the planning of future exploration missions. We show
how RAD is used as a space weather monitor on Mars and present RAD
measurements of solar-induced effects on the radiation field (e.g., SPEs, Forbush decreases, ICMEs). RAD measurements of timing and
intensities at 1.5 AU on Mars of such features give valuable insight into
particle propagation throughout the heliosphere. We then present RAD
measurements of the regolith shielding effect by natural terrain on Mars,
which are crucial for the validation and design of radiation shelters
utilizing in-situ resources on Mars. Finally, we give an overview on
necessary future radiation observations to prepare for human exploration
of Mars.
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Elliott H. A. Dayeh M. Livadiotis G. Sokol J. Alterman B.
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Exploring the Solar Wind in the Outer Heliosphere [#2137]
The
outer heliosphere is a vastly under sampled region worthy of further
exploration included in the Heliophysics 2050 plan. This presentation reviews
key findings about the plasma properties in the outer heliosphere such as
radial trends in (1) plasma properties, (2) variability of plasma properties,
and (3) relationships between plasma parameters. We discuss limitations of
current and past outer heliospheric observations along with potential insights
Heliophysics can gain in the short term with current assets and in the long
term with improved instrumentation on future missions.
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Eriksson S. Pyakurel P. S. Mallet A. Swisdak M. Cassak P. A. Opher M. Provornikova E. Turner D. L. Bale S. D. Richardson J. D. Desai M. Alexandrova A.
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Magnetic Reconnection Science in the
Outer Heliosphere [#2018]
There
is plentiful evidence of Alfvénic magnetic field
reconnection exhausts across inner heliosphere current sheets of many spatial
scales. Most events are observed at time scales ranging from the highest
plasma instrument cadence available in the solar wind to several minutes with
a few known examples also reported at the hour time scale of Heliospheric
Current Sheet (HCS) crossings. These exhausts are the “smoking guns” of
magnetic reconnection X-lines that change the magnetic topology where current
sheets form, whether due to plasma turbulence or associated with large-scale
HCS sector boundaries of the solar magnetic field. Inner heliosphere
reconnection exhausts at 0.3-5.4 AU are mostly observed in a low ion beta
(βi<1) regime of the thermal solar wind plasma, possibly due to a
tearing mode instability, where βi is the ratio of proton plasma
pressure to magnetic field pressure. The New Horizons mission provided the
first measurements of interstellar H+ and He+ pickup ions (PUIs) beyond the
hydrogen ionization cavity and demonstrated a much hotter (TPUI~3·106
K) and tenuous (NPUI~5·10–4 cm–3) PUI proton
distribution at 20 AU as compared with the cold (Tp~1·104 K) and
dense (Np~2·10–2 cm–3) population of thermal solar wind
protons. The outer heliosphere proton distribution effectively consists of a
core of cold thermal solar protons and a halo of hot, tenuous pickup protons.
The estimated βi<2 regime of cold solar protons suggests that
spontaneous reconnection could be active across local CSs in the outer
heliosphere, as these βi values are similar to
those confirmed across exhausts of the inner heliosphere. In contrast, the
PUI-associated proton βPUI, which may be as high as 20–100 in the outer
heliosphere, suggests that spontaneous reconnection may be prohibited at
ion-scale current sheets involving the hot PUIs. We discuss whether
spontaneous reconnection may proceed in the outer heliosphere through a
decoupling of cold solar wind protons with small Larmor radii across
ion-scale current sheets without a direct dynamic coupling of hot PUI protons
with larger Larmor radii.
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Galli A. Redfield S. Provornikova E. Kucharek H. Swaczyna P.
Sokol J. M. Kubiak M.
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The Potential of the Interstellar Probe for Measuring In-Situ
Interstellar Neutrals [#2009]
A
near-term interstellar probe would enable in-situ measurements of the
interstellar medium all the way from the Earth to the heliosheath
and beyond the reaches of the heliopause. These revolutionary measurements
would reveal how the interstellar medium is filtrated and deflected by our
heliosphere and the chemical and isotopical
composition of the unperturbed interstellar medium itself.
Two different types of instruments with a high heritage from previous space
missions can be used to measure neutrals on board the Interstellar Probe
in-situ. Their capabilities and shortcomings are complementary:
1. Neutral gas mass spectrometer: A
time-of-flight detector combined with a dual entrance system (closed source
for volatile species, accumulated sampling for all species and ionization
states) can identify elemental and isotopic abundances of all neutral
species, covering all atomic species up to Fe. Masses up to 1000 atomic mass
unit can easily be achieved and also (rare) larger
molecules or dust fragments can be handled. Densities along the trajectory
can be measured to obtain timeseries, but no information on velocity,
temperature, or flow direction of particles is obtained.
2. Low-energy Energetic Neutral Atoms (ENA) imager: An ENA-Lo imager (similar to instruments flown on the Interstellar Boundary
Explorer and the Interstellar Mapping and Acceleration probe) can measure
intensities, energies, and directions of interstellar neutrals and heliosheath ENAs between 10 eV and 1 keV energy, usually
distinguishing between the three major species H, He, and O. If a scanning
field of view is used, these measurements enable 2D-sky maps of the primary
and secondary populations of interstellar neutral H, He, and O, from which
spatial and temperature distributions of the different populations can
be detrived.
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Gil A.
Berendt-Marchel M. Modzelewska R. Moskwa Sz. Siluszyk A. Siluszyk M. Tomasik L. Wawrzaszek A. Wawrzynczak A.
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Analysis of Strong Geomagnetic Storms and
Electrical Grid Failures in Poland for the Period 2010–2014 [#2016]
We
analyzed strong geomagnetic storms for the period of the first half of the
solar cycle 24. Strong geomagnetic storms were observed only several times
during the studied time interval, generally accompanied by a southwardly
directed heliospheric magnetic field, Bz,
component. We utilized self-organizing maps, statistical and superposed epoch
analysis, showing that during and right after intense geomagnetic storms, the
number of transmission line failures raised, which might be of solar origin.
We also examined the temporal changes of the number of failures during 2010–2014
and found the rising linear trend of electrical grid failures occurrence
possibly related to solar activity level. We collated our results with the
geoelectric field computed for the Poland’s region using a 1-D layered
conductivity Earth model.
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Goetz C. Gunell H. Volwerk M. Beth A. Eriksson A. Galand M. Henri P. Nilsson H. Simon Wedlund C. Alho
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Cometary Plasma Science [#2021]
Comets
hold the key to the understanding of our solar system, its formation
and its evolution, and to the fundamental plasma processes at work both in it
and beyond it. A comet nucleus emits gas as it is heated by the sunlight. The
gas forms the coma, where it is ionised, becomes a plasma and eventually interacts with the solar wind.
Besides these neutral and ionised gases, the coma
also contains dust grains, released from the comet nucleus.
As a cometary atmosphere develops when the comet travels through the solar
system, large-scale structures, such as the plasma boundaries, develop and
disappear, while at planets such large-scale structures are only accessible
in their fully grown, quasi-steady state. In situ measurements at comets
enable us to learn both how such large-scale structures are formed or
reformed and how small- scale processes in the plasma affect the formation
and properties of these large scale structures.
Furthermore, a comet goes through a wide range of parameter regimes during
its life cycle, where either collisional processes,
involving neutrals and charged particles, or collisionless
processes are at play, and might even compete in complicated transitional
regimes. Thus a comet presents a unique opportunity
to study this parameter space, from an asteroid-like to a Mars- and
Venus-like interaction.
The Rosetta mission and previous fast flybys of comets have together made
many new discoveries, but the most important breakthroughs in the
understanding of cometary plasmas are yet to come. The Comet Interceptor
mission will provide a sample of multi-point measurements at a comet, setting
the stage for a multi-spacecraft mission to accompany a comet on its journey
through the solar system.
This white paper reviews the present-day knowledge of cometary plasmas,
discusses the many questions that remain unanswered, and outlines a
multi-spacecraft ESA mission to accompany a comet that will answer these
questions by combining both multi-spacecraft observations and a rendezvous
mission, and at the same time advance our understanding of fundamental plasma
physics and its role in planetary systems.
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Green J. Dong C. Hesse M. Young C. A.
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Space Weather Observations and Modeling in
Support of Human Exploration of Mars [#2077]
What
role can Heliophysics play in the support of human exploration of Mars? As a
view of the future, consider the following:
Humans on Mars will stay in an Exploration Zone (EZ). A comprehensive
Mars SW modeling (MSWM) system starts at the Sun, with 360o coverage by
observations and models that ingest relevant data as more become available,
and which is capable of evolving in response to new
scientific insights. The MSWM system also employs Martian atmospheric models
and extends those outward by coupling to suitable SW-induce magnetopause
models. This whole system then provides the breadth of relevant SW
information as well as output suitable for scientific research and validation
and verification. The MSWM system is designed to provide rapid dissemination
of information to Earth controllers, astronauts in transit, and those in the
EZ by producing alerts.
Human Exploration of Mars will be both an international space agency sector
and a commercial endeavor. All sectors provide significant resources and
capabilities in a highly coordinated fashion. A series of key measurements
are fed into the MSWM that include: 1) next-generation STEREO solar
observations; 2) Mars L1 solar and solar wind observations; 3) low-altitude
planet-asynchronous orbiter observations monitoring dynamical phenomena
rapidly evolving in space and time; and 4) planet-wide array of ground-based
magnetometers, seismic, and other meteorological instruments. The
communication infrastructure consists of 3 spacecraft at aerostationary
orbit perform the following functions: 1) relays all surface voice/video/data
back to Earth; 2) provides Earth to the EZ relay capability; 3) atmospheric
weather observations whose telemetry is relayed to the EZ and to Earth; 4)
particles and field sensors whose telemetry is relayed to the EZ and to
Earth.
Summary: We must first develop a comprehensive Mars Heliophysics SW roadmap
in which the first elements are in the next HD Decadal. The HD Decadal must
also have potential new SW missions that are not being enabled in any other
way but must be executed. The roadmap should include key HD payloads that
could be provided to PSD Mars missions (orbiters, landers, rovers) through
joint solicitation or strategic agreements. This approach should also apply
to international space agencies and new commercial space partners as well. In
other words, HD needs additional funding and it will
need a New Initiative in order to accomplish this new science.
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Hill M. E. Giacalone J. Florinski V. F. Opher M. Turner D. L. Allen R. C. Brandt P. C. Cummings A. C. Decker R. B. Dialynas K. Kollmann P. Kota J. Leske R. A. Mewaldt R. A. McNutt R. L. Jr. Mostafavi P. Nikoukar R. Provornikova E. Richardson J. D. Roelof E. C. Zank G. P.
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Galactic Cosmic Rays Near the Interstellar Interface [#2067]
At one
time cosmic ray experiments reached the required altitude in the wicker
basket of a hydrogen balloon, drifting with the wind thousands of meters
above the Austrian countryside, as in Victor Hess’s famous experiments over a
century ago. In present day, analogous experiments reach their “high” vantage
point of 150 AU from the Sun aboard the Voyager 1 (V1) spacecraft, immersed
in the interstellar wind of the very local interstellar medium (VLISM), the
frontier region connecting our heliosphere with the rest of the Milky Way
galaxy. Since 2012, V1 has been in the VLISM, beyond the heliopause (HP),
measuring galactic cosmic rays (GCRs) — high energy particles accelerated
elsewhere in the galaxy, probably in energetic events such as supernovae. The
VLISM — which was also entered in 2018 by Voyager 2 (V2) — is not at all
isolated from the effects of the Sun; it is in fact actively perturbed by
solar activity, and so, dynamically, the VLISM is very much a part of the
heliosphere. Yet in other ways it is also not quite a part of the
heliosphere, at least the heliosphere as we have known it through several
decades of in situ observation. This fascinating interface between the
heliosphere and interstellar space, the VLISM, is a place, as we currently
understand it, awash in the plasma, suprathermal
particles, gas, and dust born in distant stars and galactic clouds, not the
familiar products of the Sun. It is a place that is magnetically connected to
the galaxy’s magnetic field, not directly to the Sun along the spiraling
Parker field, and where GCRs are the dominant mobile charged particle, not
ions and electrons accelerated in the solar wind or at the Sun. The VLISM is
new to us. And the GCR phenomena available for study from this new vantage
point, for a few more years while Voyager observations continue, are ripe for
an intensifying level of study. In this presentation we will discuss science
questions associated with GCRs near and within the VLISM, as also discussed
by Hill et al. 2021 (see
https://www.hou.usra.edu/meetings/helio2050/pdf/4097.pdf and
references therein).
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Kirk M. S. F. Lindsay S. S. Lucas M. P.
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Discovering the Ancient Sun on Solar
System Bodies [#2156]
How
typical is the Sun in the universe? What was the role of solar activity to
create a habitable environment or the origin of life on Earth? The solar
sunspot cycle is the longest-running astrophysical measurement, beginning in
1610 and consistently measured since 1749. Carbon and Beryllium radiometric
dating has reliably reproduced a solar activity proxy by estimating the
atmospheric cosmic-ray production of those isotopes going back about 10,000
years. However, to answer these bigger questions, we need to understand how
active the Sun was millions, or billions of years ago. Geology routinely
records events on this time scale, but on Earth solar activity isn’t preserved in the crust. We need a geologic source that
shows the effects of space weathering that does not live on Earth. A location
is needed that is not shielded by a strong magnetic field and has regular
deposition of new material over weathered rocks to give us an estimate of a
time-dependent change in solar energetic particles. To this end, a few prime
solar system targets come to mind:
Lunar regolith, Martian Tharsis volcanos, or
geologically active icy satellites such as Europa and Enceladus. In each
case, there is consistent deposition of virgin material that is slowly
altered by proton bombardment. This work puts forward a new mission concept
that will outline the multi-decadal effort to take in-situ measurements of a
solar activity proxy in the solar system. This mission would use a
combination of in-situ measurement techniques to determine ion abundances
(e.g., laser ablation combined with a mass spectrometer) and mineral
chemistry (e.g., X-ray fluorescence or X-ray photoelectron spectroscopy –
XPS) at varying core depths. We also explore the benefits and constraints of
a sample return mission to further decipher trace chemistry. These
measurements of space weathering products will act as a proxy solar activity
over the geologic record of the collected core samples.
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Lee C. O. Luhmann J. G. DiBraccio G. A. Halekas J. S. Espley J. R. Gruesbeck J. R. Larson D. E. Lillis R. J. Rahmati A. Eparvier F. Thiemann E. M. B. Chamberlin P. Schneider N. M. Jain S. K. Milby Z. Xu S. Brain D. A. Curry S. M. Jakosky B. M.
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Space Weather at Mars: Six Years
of MAVEN Observations [#2126]
The
Mars Atmosphere and Volatile EvolutioN (MAVEN)
spacecraft has been continuously observing the variability of solar soft
X-rays and EUV irradiance, monitoring the upstream solar wind and
interplanetary magnetic field conditions, and measuring the fluxes of solar
energetic ions and electrons since its arrival at Mars in September 2014,
towards the end of the maximum phase of Solar Cycle 24. Relevant observations
from the instrument suite include quiescent and flaring solar soft X-ray and
EUV irradiance based on measurements by the solar Extreme Ultraviolet Monitor
(EUVM), the fluxes of solar energetic particles accelerated by shocks at the
Sun and in the heliosphere from the Solar Energetic Particle (SEP)
instrument, the solar wind plasma parameters by the Solar Wind Ion Analyzer
(SWIA), the vector measurements of the interplanetary magnetic field (IMF) by
the Magnetometer (MAG), and the auroral observations by the Imaging UltraViolet Spectrograph (IUVS).
This presentation will review
observations of space weather at Mars over a 6-year period made by MAVEN,
encompassing the maximum, declining, and minimum phases of Solar Cycle 24 to
the start of Solar Cycle 25. The comprehensive set of observations at Mars
has given us the opportunity to better characterize the local EUV and solar
wind conditions during active and quiet space weather periods and to analyze
the response of the martian system to the upstream disturbances. Some of the
Mars-impacting space weather events observed by MAVEN include the heating of
the neutral atmosphere and enhancement of the lower ionosphere triggered by
large flares, the perturbation of the Martian induced magnetosphere and ion
escape enhancements due to the passage and interaction of an interplanetary
coronal mass ejection (ICME) and stream interaction regions (SIRs), and the
triggering of diffuse auroral emission in the lower Martian atmosphere due to
the precipitation of electrons during a SEP event.
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Livadiotis G.
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The Role of Kappa Distributions in
Space Thermodynamics [#2079]
Classical
collisional particle systems residing in thermal equilibrium have their
particle velocity/energy distribution function stabilized into a
Maxwell-Boltzmann distribution. On the contrary, space plasmas are collisionless particle systems residing in stationary
states characterized by a non-Maxwellian behavior, typically described by
kappa distributions. These distributions have become increasingly widespread
across the physics of space plasma processes, describing particles in the
heliosphere, from the solar wind and planetary magnetospheres to the heliosheath and beyond, the interstellar and
intergalactic plasmas. A breakthrough in the field came with the connection
of the kappa distributions with statistical mechanics and thermodynamics. In particular, kappa distributions (i) maximize the
entropy of nonextensive statistical mechanics under
the constraints of canonical ensemble, (ii) characterize particle systems
exchanging heat with each other eventually stabilized at a non-classical
version of thermal equilibrium, and (iii) constitute the unique description
of particle energies consistent with polytropic behavior. Recognizing the
growing importance of this subject, space science is obliged to improve
understanding of the fundamentals behind the statistical and thermodynamic
framework of kappa distributions and its applications in space
plasma physics.
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Miller J. A. Fields B. D.
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Simulating Supernova Collisions with the Heliosphere [#2060]
As the
Sun moves throughout the Galaxy, the outer heliosphere encounters many
different environments. Amazingly, there is now strong evidence for dramatic
heliosphere compression in the past due to a nearby supernova explosion. Live
radioisotopes (undecayed 60Fe, half-life of 2.6 Myr)
found in ocean sediments, crusts, Antarctic snow, and even Apollo lunar
samples were delivered by a supernova 2–3 Myr ago
and possibly another 7–8 Myr ago. These same
supernovae that deposited 60Fe must have had extreme effects on
the heliosphere.
The modern heliosphere has no memory of this event, so we must turn to
simulations to understand this process better. We employ idealized
hydrodynamic simulations to show the heliosphere’s response to a nearby
supernova explosion. Our group has investigated this event using idealized
axisymmetric 2D hydrodynamic simulations. We have run simulations for
supernova blasts spanning the range of possible distances informed by the
60Fe data, and for different orientations of the heliosphere. We initialize
the solar wind according to data from the Voyager and Ulysses missions.
The location of the heliopause is given by pressure balance. We find that the
most important parameter is the distance to the supernova. A supernova 50 pc
away will compress the heliopause all the way to 13 AU. Since the solar wind
ram pressure is similar in the polar and equatorial directions, the
orientation makes little difference for the structure of the heliosphere.
Finally, we note that these simulations have implications for exoplanets,
particularly those in the vicinity of supernova remnants. Future work, such
as solar wind variability and the heliosphere through the life of the
supernova remnant, will be discussed. Other future work involves studying how
cosmic rays accelerated in the supernova remnant could propagate through the
solar system and affect Earth. This project investigates how the heliosphere
changes in response to one of the most extreme environments
it encounters.
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Oliveira D. M. Weygand J. M. Ngwira C. M. Silveira M. V. D. Zesta E. Giles B. L.
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Local Intense Ground dB/dt Variations Caused by
Substorm-Time Injections Triggered by Interplanetary Shocks with
Different Inclinations [#2065]
The
impact of interplanetary shocks on the magnetosphere can trigger magnetic
substorms that intensify auroral electrojet currents. These currents enhance
ground magnetic field perturbations (dB/dt), which in turn generate
geomagnetically induced currents (GICs) that can be detrimental to power
transmission infrastructure. We perform a comparative study of dB/dt
variations in response to two similarly strong shocks, but with one being
nearly frontal, and the other, highly inclined. Multi-instrument analyses by
THEMIS and GOES show that nightside substorm-like energy injections are more
symmetric, stronger, and occur faster in the case of the nearly head-on shock
impact. On the ground in North America, THEMIS magnetometers show that dB/dt
is more intense and occurs faster in the case of the nearly frontal shock.
THEMIS all-sky images show a fast and clear poleward auroral expansion in the
first case, which did not clearly occur in the second case. The spherical
elementary currents (SEC) technique shows that strong field-aligned currents
occur in both cases, but the current variations resulting from the inclined
shock impact are slower compared to the nearly frontal case. SEC analyses
also reveal that the geographic areas with dB/dt surpassing the thresholds of
1.5 and 5 nT/s, usually linked to high-risk GICs, are
larger and occur earlier due to the symmetric compression in the first case.
These results suggest that shock impact angles control the location and
intensity of dB/dt variations on the ground during substorms, with explosive
energy release by the magnetotail through fast and intense electron fluxes
triggered by symmetric compressions, which does not clearly occur under
asymmetric compressions. Therefore, these results suggest that empirical and
physics-based models for ground dB/dt variations should consider the shock
impact angle as a very important solar wind driver factor that can
subsequently cause intense GICs on the ground during magnetospheric
substorms, even for isolated (no magnetic storm) events. Future statistical
investigations using several shocks with different orientations and
multi-instruments in space and on the ground, the last involving
collaborations of several worldwide magnetometers array, will help understand
not only the role of symmetric/asymmetric compressions in causing dB/dt variations
with different levels at different locations, but also general shock geoeffectiveness and its direct space
weather implications.
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Opher M. Zank G. Florinski V. Fuselier S. Giacalone J. Toth G. Drake J. Swisdak M. Zieger B. Galli A. Dayeh M. Tenishev V. Izmodenov V. Korenbleuth M. Powell E. Baliukin I. Zirnstein E. Michaels A. Dialynas K. Krimigis S. Cummings A. Dayeh M. Decker R. Elliot H. Gkioulidou M. Hill M. Nikoukar R. Roussos E. Szabos A. Kota J. Provornikova E. Mostafavi P. Brandt P. McNutt R. Gombosi T. Stone E. Schwadron N. Stern A. Loeb A.
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Our Heliospheric Shield, a Case of a Habitable Astrosphere: Open Science Questions [#2012]
The
heliosphere is an immense shield that protects the solar system from harsh
galactic radiation. The heliosphere is a window into processes occurring in
all other astrospheres. Understanding these processes enables predictions
about the astrospheric conditions necessary to
create habitable planets.
As the Sun moves through the interstellar medium it carves a bubble called
the heliosphere. A fortunate confluence of space missions has provided a
treasury of data on this structure and its interaction with the interstellar
medium and the solar wind that will likely not be repeated for decades. More
specifically, the in-situ measurements by the Voyager, Pioneer and New
Horizon spacecraft combined with the all-sky ENA images of the heliospheric
boundary region by the Interstellar Boundary Explorer (IBEX) and Cassini
missions have transformed our understanding of the heliosphere. However, many
fundamental features of the heliosphere are still not well understood. These
aspects include the basic “shape” of the heliosphere, the extent of its tail,
the nature of the heliosheath (HS), and the
structure of the local interstellar medium (LISM) just upstream of the
heliopause (HP). Other remaining puzzles are:
1) The acceleration region and mechanism for anomalous cosmic rays
(ACRs); 2) The HS is 30–50% thinner than current models predict; 3) the
plasma flows (Fig. 1) and energetic particles intensities are drastically
different at V1 and V2; 4) The magnetic field direction does not change at
the HP and we do not know how far from the HP the solar wind’s influence
extends 5) The significant increase in Galactic Cosmic Rays (GCRs) just prior
to the HP crossings observed by both V1 and V2 and the GCR anisotropies
observed in the LISM are not understood fully. The ENA observations add to
the list of puzzles. IBEX detected a global feature, the ribbon. INCA on
Cassini measured a similar, but broader feature at higher energies, called
the “Belt”. The source of these features is controversial; the models
proposed to explain these features rely on assumptions for the interstellar
conditions such as the draping of the interstellar magnetic field and the
level of turbulence in the LISM. This work will highlight the key science
questions for the outer heliosphere and the progress made so far within the
NASA DRIVE Center SHIELD.
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Ratkiewicz R. E.
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What Does the Heliosphere Look Like? [#2022]
Authors
of numerical simulations of the heliosphere tried to use all data provided by
Voyagers, IBEX and other missions to validate the
obtained models they created. In particular crossing
the termination shock and the heliopause by both Voyager spacecraft and the
discovery of the IBEX ribbon enabled to determine three criteria to be
fulfilled by any model of the heliosphere:
1. The model should place the termination shock and the heliopause at
the distances where both Voyager spacecraft crossed them. 2. The SW and LISM
flows obtained from the numerical simulation should follow the plasma flow
measured by Voyagers. 3. The model should reproduce the shape of the IBEX
ribbon.
Up to now however, none of the obtained heliosphere models met all the
basic fit criteria. Therefore we still do not know
the structure and shape of the heliosphere. To achieve the proper model of
the heliosphere we need the numerical methods that allow us to fully cover
physics of problem being solved. The remedy for this seems to be to construct
a numerical model using the Particle-in-cell method.
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Sadykov V. M. Kosovichev A. G. Kitiashvili I. N. Oria V. Nita G. M. Illarionov E. A. Jiang Y. O’Keefe P. Fereira S. H.
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Development of “All-Clear” Prediction of Solar Proton Events Using
Machine Learning [#2046]
Solar
Energetic Particles (SEPs) are among the most dangerous transient effects of
solar activity. Representing hazardous radiation, SEPs may adversely affect
the health of astronauts in outer space and therefore can endanger current
and future space exploration. In this work, we consider the important problem
of developing “all-clear” forecasts of Solar Proton Events (SPEs). First, we
highlight our progress in developing an online-accessible database that
integrates a variety of solar and heliospheric data, metadata, and
descriptors related to SPEs. Use of this database is conducted through an
Application Programming Interface (API) and a web application for data search
and retrieval. Second, we construct daily forecasts of Solar Proton Events
based on the properties of magnetic fields in Active Regions (ARs), preceding
soft X-ray and proton fluxes, and statistics of solar radio bursts. Machine
learning (ML) is applied to an artificial neural network of custom
architecture designed for whole-Sun input. The predictions of the ML model
are compared with the SWPC NOAA operational forecasts of SPEs. Our
preliminary results indicate that 1) for AR-based predictions, it is
necessary to take into account ARs at the western limb and on the far side of
the Sun, 2) characteristics of the preceding proton flux are the most
important for prediction, 3) daily median properties of ARs may be excluded
from the forecast without significant performance loss, and 4) ML-based
forecasts outperform SWPC NOAA forecasts in situations in which failing to
predict an SPE event is very undesirable. The introduced approach indicates
the possibility of developing robust “all-clear” SPE forecasts by employing
machine-learning methods.
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Shneider C. Hu A. Tiwari A. K. Bobra M. G. Battams K. Teunissen J. Camporeale E.
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A Machine-Learning-Ready Software Framework
Prepared for the SoHO and SDO Missions for Space
Weather Readiness [#2036]
We
present a software framework that allows for user-defined selection criteria
and a range of pre-processing steps to generatea
standard data set from solar images. Our software framework works with all
image products from both the Solar and Heliospheric Observatory (SoHO) mission as well as the Solar Dynamics Observatory
(SDO) mission. We discuss a data set produced from SoHO
mission’s multi-spectral images which is both free of missing or corrupt data
and is temporally synced making it ready for input to a machine learning
system. Machine-learning-ready images are a valuable resource for the
community because they can be used, for example, for forecasting space
weather parameters. We illustrate the use of this data with an application of
a deep convolutional neural network (CNN) to a subset of the full SoHO data set in an effort to
provide a 3–5 day-ahead forecast of the north-south component of the
interplanetary magnetic field (IMF) observed at L1. We present baselines from
applying a Gaussian Naive Bayes classifier and CNN methodology.
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Sokol J. M. Dayeh M. A. Fuselier S. Galli A. Swaczyna P. Rahmanifard F.
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Solar Environment as Driving and Constraining Factor in the Study of
the Heliosphere and the Local Interstellar Medium [#2035]
The
heliosphere, a result of solar outflow in the surrounding interstellar medium,
is a fundamental subject of numerous studies and observations. Measurements
from successful past and present missions like, e.g., Ulysses, IBEX, New
Horizons, and Voyager constantly broaden our knowledge about its properties,
solar wind dependence, interaction with the very local interstellar medium
(VLISM), and the VLISM itself. Remote measurements collected from the Earth’s
vicinity require careful and thoughtful interpretation of the observed
signals and the implementation of proper solar environment corrections.
On one hand, solar wind and solar extreme ultraviolet radiation ionize the
incoming flux of interstellar atoms measured close to Earth’s orbit. The
ionization losses vary depending on species. Hydrogen, the most abundant
species, is the most prone to the solar environment and undergoes the
greatest losses. The high ionization rate creates an ionization cavity at a
few astronomical units from the Sun including Earth’s orbit. The density of
interstellar hydrogen atoms entering the heliosphere is reduced by about 95%
before the atoms reach detectors at 1 au. Derivative populations like
energetic neutral atoms (ENAs) and pick up ions are also affected. These
severe losses significantly affect the scientific interpretation of the
measurements. Studies have shown that to mitigate the adverse losses of the
interstellar measurements at least outside the ionization cavity are needed.
On the other hand, solar wind shapes the dimensions of the heliosphere and
organizes the processes in its boundary regions. The latitudinal variation of
the solar wind outflow and the variation due to the solar activity cycle are
reflected in the global structure of the heliosphere observed by ENAs. Thus,
the dual role of the solar environment in the study of the global heliosphere
is unquestionable.
We discuss the role of the solar environment in the study of interstellar
atoms, ENAs, and pick-up ions inside the heliosphere. We present
research-based arguments for the need to conduct measurements outside the
solar ionization cavity to improve the quality of the study of the
heliosphere and to advance our understanding of the
interstellar neighborhood.
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Swaczyna P.
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Helium Energetic Neutral Atoms as a Tool to
Study the Structure of the Heliosphere and the Local Interstellar Medium [#2080]
Energetic
neutral atoms (ENAs) enable remote observations of distant regions of the
heliosphere and the very local interstellar medium (VLISM). Most ENA
instruments observe only hydrogen ENAs, which are expected to be the most abundant
species in heliospheric ENA fluxes. However, heavier species may also be
produced in the heliosphere and beyond, including helium ENAs. Energetic
hydrogen PUIs, which are the primary source of ENAs from the inner heliosheath, are neutralized on length scales of a few
hundred au. Hence, they are almost extinct beyond this distance from the
termination shock, and the distant structure of the global heliosphere cannot
be mapped using hydrogen ENAs. Conversely, helium PUIs are neutralized on
scales approximately 10 times longer in the heliosheath,
and thus they can provide us with the information where the solar wind plasma
escapes the heliosphere. Does the heliosphere have one tail, or is the solar
wind concentrated in two jets? Helium ENAs are also much less attenuated due
to ionization processes in the heliosphere and the LISM. This may enable
observation of distant sources of the ENAs in the LISM up to about 20,000 au
from the Sun. Such sources may be expected in the LISM due to the nearby
boundary of the Local Interstellar Cloud. Consequently, helium ENAs may bring
discoveries of new ENA sources. Due to expected low ratio of helium ENA
events to hydrogen ENA events, instruments need to include high-resolution
mass spectrometer ability, e.g., time-of-flight detector. However, even if
the number of observed atoms is much lower compared to hydrogen ENAs, we
should be able to register individual events, which mapped on the skymap can show regions of higher helium
ENA emission.
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Turner D. L. Vourlidas A.
Merkin V. Likar J. Nikoukar R. Sotirelis T. Zhang Y. Allen R. Paxton L. Ho G.
Ukhorskiy A.
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A Vision for Heliophysics’ Role in Space Weather Research as We Advance
Towards 2050 [#2088]
Space
weather encompasses all aspects of the effects and consequences of the
dynamic space environment on human health and technological systems spanning
from on Earth itself (e.g., geomagnetically induced currents – GICs) to the
Moon and Mars and on to deep space and systems beyond our home world (e.g.,
remote spacecraft). Societal demand for improved space weather evaluation and
prediction models is ever-growing as humanity becomes more and more reliant
on space-based technology and strives to explore our solar system. Here, we
present our vision for a system-of-systems approach to better empower our
next generation space weather capabilities, the Space Weather Aggregated
Network of Systems: SWANS. By 2050,
SWANS will serve society’s space weather needs by networking an aggregated
system of in situ and remote sensing observatories, both space-based and
ground-based, and state-of-the-art modeling facilities and centers that will
provide space weather end users with accurate, on demand resources to predict
the consequences of space weather on systems distributed on and around Earth
and throughout the Solar System. From the solar origins and sources of space
weather to the cis-lunar and coupled geospace
environments, SWANS will capture the interconnected and complex nature of
space weather, always with the reality of space weather hazards and threats
and end-user needs in mind. In addition to improved predictive (forecast,
nowcast, and hindcast) models, next-generation climatological models will
also be a critical product of SWANS, since climatological models are immensely
valuable for engineering design and very long-term prediction and uncertainty
models. SWANS models will encompass a variety of data-ingestive
and/or -assimilative physics-based, empirical, and statistical models, some
of which may also be empowered by machine learning algorithms and data
analytics. In this poster, we outline our vision for SWANS and detail several
of the critical observational and modeling gaps that must be filled and
recommendations for how we can make SWANS a reality by 2050.
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Vadas S. L. Becker E. Bossert K.
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Medium-Scale GWs in the F Region from the Polar
Vortex via Multi-Step Vertical Coupling [#2051]
In the
past few years, mountain waves been shown to create fast medium and
large-scale “tertiary” atmospheric gravity waves (GWs) in the F region via
multi-step vertical coupling (Vadas and Becker,
2019, JGR). In this mechanism, momentum and energy are deposited where
mountain waves break/dissipate in the stratosphere or mesosphere, which
creates local body forces (i.e., horizontal accelerations of the neutral
atmosphere) that excite secondary inertia GWs. These GWs propagate into the
lower thermosphere where they dissipate from breaking/dissipation via
molecular viscosity, which excites a new set of faster and deeper GWs, so-called
“tertiary GWs.” These tertiary GWs were shown to reproduce the travelling
atmospheric disturbance (TAD) hotspot seen in the wintertime over the
Southern Andes in GOCE and CHAMP data (Becker and Vadas,
2020, JGR). However, up until now, no modeling work has analyzed how momentum
and energy are transferred to the F region via GWs generated from the polar
vortex, although such GWs are known to be an important source of wintertime
northern hemisphere GWs in the stratosphere. Because these GWs are slow, they
cannot propagate directly to the F region due to dissipation from
breaking/critical level filtering in the stratosphere & mesosphere and
dissipation from molecular viscosity in the thermosphere (Vadas,
2007, JGR). However, Frissell et al (2016, JGR)
found that daytime MSTIDs observed by SuperDARN
were strongly correlated with the polar vortex. In this study, we present a
“waves from below” modeling case study during the northern hemisphere winter
where we analyze GWs generated from the polar vortex. We analyze the GWs
created at each step of the multi-step coupling process, which starts from
the excitation of GWs by the polar vortex in the stratosphere, to the
breaking/dissipation of these GWs in the lower mesosphere and the formation
of local body forces and heatings, to the
excitation of the secondary GWs from these forces/heatings
and comparison with lidar data, to the breaking/dissipation of these
secondary GWs in the mesosphere, and so on. We analyze the individual steps
of this coupling process up to the F region in order to
better-understand and characterize the resulting medium-scale GWs there “from
below” from this physical process.
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Weimer D. R. Borovsky J. E. Allen R. C. Turner D. L.
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The Structure of Flux Tubes in the IMF:
A Major Source of Uncertainty in Space Weather Predictions
and Research [#2052]
Observational
studies have indicated that the solar wind transports a network of entangled
magnetic flux tubes, that may originate from the solar surface or they may be
created in situ by turbulence. These flux tubes have a variety of dimensions,
orientation angles, and other properties. So far much of what is known about
these flux tubes has been deduced from single-point measurements in the
upstream solar wind, along with the several case studies with multi-point
observations. The flux tubes have a wide distribution of sizes, with a mean
diameter of about 70 Re. As stated by Borovsky
[2008], to fully understand the nature of the solar wind in light of the
network of flux tubes, six science tasks must be accomplished: (1) determine the properties of
discontinuities in the solar wind, (2) determine the properties of the
individual flux tubes, (3) determine the properties of the flux-tube network
and determine its evolution, (4) learn the origin of the flux-tube texture,
(5) re-analyze the solar-wind turbulence excluding fluxtube walls, and (6)
assess the impacts of this flux-tube texture on Earth’s
magnetosphere-ionosphere system and more generally on heliospheric physics.
The last item in this list is particularly important, while it does not get
the attention it deserves. Almost all scientific studies focusing on the
coupling between the solar wind and its magnetic field with the Earth’s
magnetosphere and ionosphere have relied on measurements from a satellite
orbiting around the first Lagrange point, sunward of the Earth. While nearly
all scientific, analysis, numerical modeling, and space weather forecasting
assume a uniform solar wind, the flux tube structure instead is such that the
magnetic field measured some distance off the Earth-Sun line at L1 is not
guaranteed to intersect with the Earth in a uniform manner with expected
arrival times. As a result, the uncertainties in the fundamental structure of
the IMF could be the dominant source of uncertainty in space physics research
and operational forecasting.
This topic is particularly timely, given that recent NASA solicitations have
required that proposers “must consider data and model uncertainty and how
sources of error impact the results.” We
propose that a strategic, multi-decadal science framework for solar and space
physics needs to consider scientific missions and/or operational space
weather monitors consisting of at least three to four satellites in the
upstream solar wind.
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Xapsos M. A. Zheng Y. Young S. L.
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Recommending Low-Cost Compact Space Weather
Sensor Suites for NASA Missions [#2158]
With
miniaturized spacecraft (e.g. cubesats)
and instrumentation becoming an indispensable part of future space
exploration and scientific investigations, it is important to understand
their potential susceptibility to space weather impacts brought by the
sometimes volatile space environment. A multitude of complexities influence
how the space environment interacts with different space hardware/electronics.
Measurements of such impacts have been severely lacking. Therefore, we
recommend developing or procuring low-cost, low-power consumption, and
compact sensor suites (mainly for space weather purposes) and flying them, in
addition to the main instrumentation, on all future NASA (and U.S in general)
missions in order to measure and quantify space
weather impacts. Two of such suites, CREDANCE (Cosmic Radiation Environment
Dosimetry and Charging Experiment) and CEASE3 (Compact Environmental Anomaly
Sensor). are part of the Space Environment Testbed onboard the U.S. Air
Force’s DSX (Demonstration & Science Experiments). The CEASE instrument
was designed to measure energetic electrons and protons in the space
environment. It consists of two dosimeter detectors, a particle telescope and a Single Event Effect rate detector. CEASE
was designed to be an engineering instrument providing real-time warnings of
space weather hazards to spacecraft operators. CREDANCE is a third generation sensor suite consisting of a proton and
heavy ion telescope; internal charging current measurements at 3 shielding
depths; and total ionizing dose measurements at 2 shielding depths. Space
weather instruments such as CREDANCE and CEASE3 will help improve
understanding of the operational environment around spacecraft, anomaly
resolution, and improvements in space environment engineering tools. In
addition, measurements from such sensors can be of considerable scientific
value. A better understanding of space environment and its interactions with
space assets can also lead to possible cost reductions with appropriate level
of radiation hardening and by avoiding over-protection in space
instrument design.
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Zank G. P.
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Theoretical Challenges in Exploring the Outer Heliosphere and Interstellar Medium [#2093]
The
outer heliosphere is that region of the solar wind, supersonic and subsonic,
that is mediated by the interstellar medium. This is related particularly to
the entrance of interstellar neutral and the subsequent creation of pickup
ions (PUIs) and the related physics that derives from this process. By
contrast, the very local interstellar medium (VLISM) is that part of the
local interstellar medium that is in turn mediated by heliospheric processes.
This fascinating coupling of complex plasma physical processes has been
insufficiently probed in situ at the level needed to properly clarify the
physics and numerous open questions remain. This presentation will describe
the foundations of our current understanding and then focus on the open
questions that need to be resolved.
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Zesta E. Oliveira D. M. Hayakawa H. Bhaskar A.
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Estimating Satellite Orbital Drag During
Historical Magnetic Superstorms (Dst < –500 nT ) [#2066]
Understanding
extreme space weather events is of paramount importance in efforts to protect
technological systems in space and on the ground. Particularly in the
thermosphere, the subsequent extreme magnetic storms can pose serious threats
to low-Earth orbit (LEO) spacecraft by intensifying errors in orbit predictions,
leading to uncertain orbit maneuvers and ultimately the complete satellite
loss due to collisions. Extreme magnetic storms (minimum Dst
< –250 nT) are extremely rare: only 7 events occurred during the era of
spacecraft with high-level accelerometers such as CHAMP (CHAllenge
Mini-satellite Payload) and GRACE (Gravity Recovery And
Climate experiment), and none with minimum Dst <
–500 nT, here termed magnetic superstorms.
Therefore, current knowledge of thermospheric mass
density response to magnetic superstorms is very limited. Thus, in order to advance this knowledge, 4 historical magnetic
superstorms, i.e., events occurring before CHAMP’s and GRACE’s commission
times, are used to empirically estimate density enhancements and subsequent
orbital drag. The November 2003 magnetic storm (minimum Dst
= –422nT), the most extreme event observed by both satellites, is used as the
benchmark event. Results show that, as expected, orbital degradation is more
severe for the most intense storms. Additionally, results clearly point out
that the time duration of the storm is strongly associated with storm-time
orbital drag effects, being as important as or even more important than storm
intensity itself. The most extreme storm-time decays during CHAMP/GRACE-like
sample satellite orbits estimated for the March 1989 magnetic superstorm show
that long-lasting superstorms can have highly detrimental consequences for
the orbital dynamics of satellites in LEO.
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Žic T.
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The Drag-Based Modeling [#2068]
The
space weather tools are used for forecasting the spreading and arrival of
Interplanetary Coronal Mass Ejections (ICMEs) at designated positions in the
interplanetary (IP) space. Many of models are developed or still in a
development phase. The drag-based model employs the hypothesis that after CME
launch the Lorentz force ceases in the upper corona and that drag between
solar wind and CME dominates in the interplanetary space. The basis of the
hypothesis relies on the fact that the CME which is
faster than the solar wind decelerates, whereas slower one accelerates. The
drag-based kinematics is depended on the CME speed relative to the solar wind
speed. It is expected to be the case in the interplanetary collisionless environment. The simple drag-based model
utilizes the assumption of constant solar-wind speed and constant drag
parameter. Under these assumptions, the drag-based kinematics can be solved
analytically. The analytical solution gives fast forecasting calculation of
the arrival time and speed of CME to any coordinate in the heliosphere. The
basic DBM model forecasts only straightforward motion of the ICME in the IP
environment. Further development included geometric expansion using constant
cone-like ICME shape. In that case the initial shape only broadens during its
propagation. The continuation of my work introduced analysis in which initial
cone-like shape flattens during its kinematics. The leading edge flattens
under the influence of the perturbed and radially dependent solar wind to the
ICME leading rim. Next step was the introduction of a time dependent and
perturbed IP environment into the model. The enhancement examines the
possibility of application in various cases, such as automatic least-square
fitting on initial CME kinematic data suitable for a real-time forecasting of
CME kinematics, or combining the DBM into advanced numerical simulations of
the interplanetary ambient conditions.
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Zimbardo G. Perri S. Prete G. Trotta D.
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Superdiffusive Transport and Acceleration at Heliospheric Shocks [#2129]
Collisionless shock waves are considered to be one of the
main sources of energetic particles in space and astrophysical environments.
Particle acceleration is due to a first order Fermi process where particles
are scattered by the magnetic irregularities present in the upstream and
downstream medium, and gain energy at each crossing of the shock. However,
the quantitative assessment of the predictions of diffusive shock
acceleration (DSA), like spectral slope, acceleration times and maximum
reachable energies, remains elusive. Therefore, extensions of the original
model are needed.
In the last decade, we developed a scenario of superdiffusive
transport, where the particle mean square displacement grows superlinearly with time, and of superdiffusive
shock acceleration, which allows to have spectral indices harder than DSA. Superdiffusion is based on a non
Markovian statistics for particle displacements and a non Gaussian propagator. This model predicts upstream
energetic particle profiles which are power laws rather than exponential
decays, and a non-constant downstream profile. Also, shorter acceleration
times than those predicted by DSA are possible.
Thanks to in-situ observations it has been possible to make a complete
determination of the parameters of the superdiffusive
transport, such as the superdiffusive coefficient,
the energy spectral index, the typical acceleration time. The diagnostic
developed for energetic particle fluxes in the interplanetary space has been
extended to the study of the termination shock, the X-ray emission profiles
of relativistic electrons accelerated at the blast waves of some supernova
remnants, and some applications have also been made for relativistic
electrons accelerated at low Mach number shocks in galaxy cluster mergers.
These results call for a more systematic investigation of heliospheric shock
crossing, with the purpose to correlate the shock properties and the
turbulence features to the energetic particle transport regimes.
An overview of the occurrence of superdiffusion
in space plasmas will be given also in relation with results coming from
numerical simulations. Applications to the prediction of solar energetic
particle fluxes will be discussed.
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Authors
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Poster Title and Abstract
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Alzate N. Seaton D. Kirk M. Morgan H. Di Matteo S. Thompson B. Higginson A. De Toma G. Arge C.
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The Sun-Earth Connection as a Single
System: Data Analysis and Processing
Needs of Current and Future Missions [#2123]
Heliospheric
environment data constitutes a vast source of information whose potential is
far from being completely exploited. Advancement in the understanding of the
Sun/Corona/Heliosphere as a single system is connected to the improved use of
increasingly diverse data sets, and a profusion of data analysis and
processing techniques, which extract useful information from the data.
Computationally, increases in processor speed and parallel computational
techniques have improved the spatiotemporal resolution of analysis methods
and models, and advancements in physics-based numerical simulations have
improved our understanding of underlying physical processes. However, current
datasets and tools are not always used to their full potential often as a result of data and/or computational limitations
(e.g., different datasets requiring different analysis tools; data coverage
of different regions and/or properties; various programming languages; lack
of public availability of software tools to the community). New missions
present new challenges to the data analysis capabilities of the solar
heliospheric community, so developing techniques for application to current
datasets will prove valuable in interpreting and planning future datasets.
Further, emerging data science and parallel computing capabilities, combined
with the large amount of data that will be available from imminent/future
missions, will provide unprecedented opportunities. Here, we aim to discuss
how the accessibility and interoperability of various tools is essential to
extract information available about the Sun-Earth system, which serves the
heliophysics community at large, including those developing modeling and
theory. We also aim to foster discussions between researchers focused on
developing solar data analysis and processing tools and the solar
wind/heliosphere community, here and through the re-establishment of previous
community efforts such as the Solar Information Processing Workshop (SIPWork), now the Solar and Heliospheric Information
Processing Workshop (SHIPWork). The community’s
engagement in this effort is essential to fully benefit from our current
capabilities as well as to campaign for new investments in this project.
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Anderson M. M. Lazio J. Hallinan G. Airapetian V. Brain D. A. Clarke T. E. Dolch T. Dong C. F. Driscoll P. E. Fares R. Griessmeier J.-M. Farrell W. M. Kasper J. C. Murphy T. Rogers L. A. Shkolnik E. Stanley S. Strugarek A. Turner N. J. Wolszczan A. Zarka P. Knapp M. Lynch C. R. Turner J. D.
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Extrasolar Planets, Magnetic Fields, and Planetary Habitability [#2030]
Jupiter’s
radio emission has been linked to its planetary-scale magnetic field, and
spacecraft investigations have revealed that most planets, and some moons,
have or had a global magnetic field. Generated by internal dynamos, magnetic
fields are one of the few remote sensing means of constraining the properties
of planetary interiors. The Earth, Jupiter, and the other giant planets in
the Solar System generate radio emission by electron cyclotron masers in
their magnetic polar regions, driven at least in part by interactions between
their magnetospheres and the solar wind. For the Earth, its magnetic field
has been speculated to be partially responsible for its habitability by
shielding the atmosphere from the solar particle environment, including
coronal mass ejection (CME)-induced erosion. Therefore, assessing the
habitability of an extrasolar planet will require knowledge of its magnetic
field, as well as the characterization of stellar wind and transient mass
loss events around its host star, detectable through radio bursts analogous
to those produced by the Sun. Extrasolar planets also should sustain internal
dynamos, and the diversity of extrasolar planets (e.g., super-Earths) may
produce magnetospheres unlike those of Solar System planets. Detections of
extrasolar planetary electron cyclotron masers will enable measurements of
extrasolar planetary magnetic fields. Key advances in the next decade would
include the ground-based detection of the radio emission from Jovian-mass
planets and radio emission associated with stellar CMEs, as well as laying
the technological foundations for future space-based detections of the radio
emission from lower-mass planets.
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Bagenal F.
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Exploration of Planetary Magnetospheres: Opening Imagination and
Testing Theories [#2086]
The
magnetospheres span scales from barely half a planetary radius above the
surface at tiny Mercury to ~80 planetary radii at giant Jupiter. The daily
modulation is controlled by the tilt of the magnetic axis from the planetary
spin axis — barely detectable at Saturn to wildly tilted at Uranus and
Neptune. Earth and Mercury are clear examples where the internal dynamics of
the magnetosphere is dominated by reconnection between the planetary and
interplanetary magnetic fields. In the giant planet magnetospheres, rotation
dominates, with solar wind modulation being peripheral. After flybys of the
Pioneers and Voyagers, orbiting spacecraft (Galileo at Jupiter, Cassini at
Saturn) mapped out structure and revealed temporal variations. At Jupiter the Juno spacecraft is now surveying large regions
of the magnetosphere, including close passes of the polar regions, while
remote-sensing instruments measure structure and variabilities of auroral
emissions. Myriad missions exploring the Earth’s magnetosphere predicted
auroral processes for Juno to observe at Jupiter. But the giant planet is
showing significant differences from terrestrial acceleration and auroral
processes, perhaps with lessons for elsewhere in this and other solar
systems. Embedded in these vast and variable magnetospheres are moons and
rings. Not only can such moons feed the magnetosphere — such as Io dumping a
ton per second of sulfur and oxygen into the system — but the magnetospheric
particles also bombard the surfaces or interact with atmospheres, drastically
changing moons. Most importantly, the time is ripe to send orbiters to Uranus
and Neptune to explore what must be the weirdest magnetospheres in the solar
system. Magnetospheric plasmas play a vital role in the evolution of
planetary objects. Moreover, future exploration of planetary magnetospheres
provides opportunities to test the space plasma physics theories developed
from the extensive, detailed measurements at Earth by pushing parameter space
in new environments, such as changing the characteristic scales, strength and
orientation of the magnetic field, plasma pressure, etc. Thus, Heliophysics
plays an important role in understanding planetary systems both within our
solar system and likely other stellar systems.
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Bard C. M. Dorelli J. C. Kirk M. S. F. McGranaghan R. M. Narock A. A. Thompson B. J. Center for HelioAnalytics G. S. F. C.
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The Discipline of HelioAnalytics [#2076]
HelioAnalytics is the cross-disciplinary convergence between physicists,
statisticians, and computer scientists. This convergence will foster research
into advanced methodologies for heliophysical
research, and to amalgamate such methods into the broader helio
community. The data science techniques broadly termed machine learning (ML)
or artificial intelligence (AI) have been around for decades. The basic idea
is to figure out how to make computers perform tasks that humans can do well
in some respects, such as recognizing patterns, but in a way that is
applicable to vast quantities of data and that can glean subtle patterns in
data that is noisy, high dimensional, or in some other way thwarting to human
cognition. Scientific AI/ML has applications in many areas, including
Heliophysics, and has been slowly developing over the last decade. However,
we believe there is great potential beyond the simple application of AI/ML
techniques to existing data and we can attack many major heliophysical
problems with these modern methods that we cannot solve otherwise. We discuss
the current and future contributions of data science and AI/ML in five
pillars as they apply within Heliophysics:
Mission-Enabling Development, Science Data Discovery, Strategic
Partnerships and Resources, Advanced Capabilities and Method Enhancement,
Responsible Applications of AI. We also introduce the Center for HelioAnalyitcs at NASA Goddard to develop a community of
practice structured to respond to the evolving socio-technical landscape
of heliophysics.
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Barnes W. T. Rivera Y. J. Reep J. W. Del Zanna G. Higginson A. Landi E. Raymond J. C. Stansby D. S. Young P. R. Murphy N.
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The Ongoing Development and Support of Atomic
Physics in Solar and Heliospheric Science [#2131]
This
poster outlines the necessity for the availability, accessibility, and
expansion of atomic physics values and analysis tools for the meaningful
interpretation of spectroscopic observations, and their connection to the
heliosphere. Our models of the Sun, and all associated space weather
phenomena, rely on the accuracy and availability of these atomic physics
quantities. For instance, the calculation and interpretation of spectral
radiance or irradiance, including both spectral line and continuum
intensities and uncertainties, fully relies upon accurate atomic data.
Derived spectroscopic diagnostics and a full understanding of measurements
from EUV imagers (e.g. AIA on SDO) and spectrometers
(e.g. EIS on Hinode) require a detailed
understanding of the atomic physics of spectral line formation. In addition,
simulations of charge states within the radially expanding solar wind, that
connect remote to in situ ion observations, completely rely on the accuracy
of the ionization and recombination rates in the calculations. It is fair to
say that advances in almost every aspect of the physics of the solar
atmosphere, including coronal heating, solar wind, and solar activity, are
dependent on the atomic data and transition rates used to interpret solar
emission. Because of this, there are severe limitations on the scientific
return of solar and heliospheric missions which rely on the availability and
accuracy of atomic data and modeling codes for physical interpretation. Therefore,
it is critical for technological advances to be coupled with the improvement
and development of atomic physics repositories and analysis tools through
explicit funding to these projects and ongoing community level collaboration
in the upcoming decades.
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Brain D. Peterson W. Cohen O. Cravens T. France K. Glocer A. Holmstrom M. Kistler L. Ma Y. Peticolas L. Ramstad R. Seki K. Strangeway R. Vidotto A.
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Near and Long Term Prospects for Understanding
Whether Planetary Magnetic Fields are Required for Atmospheric Retention
and Habitability [#2152]
The
common assumption that planetary magnetic fields shield planetary atmospheres
from escaping to space has been increasingly questioned over the past decade,
based in part on a comparison of observations of ion escape from Earth,
Venus, and Mars. This question is timely and relevant to address in coming
years since the answer is relevant for the divergent climate evolution that occurred
at terrestrial planets in our own solar system, for the thousands of
exoplanets being discovered and characterized today, for Earth’s response to
the solar wind during geomagnetic reversals. Here we present several
approaches, via observations and modeling, to addressing this question, and
make the case that substantial progress can be made in the next decade,
leaving some long-term tasks for multiple decades.
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Burrell A. G. Halford A. Coxon J. Jones M. Jr. Zawdie K.
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Equitable Letters for Space Physics [#2075]
In our
ideal vision of the scientific community in 2050, Heliophyiscs
and the space physics communities are seen as leaders of inclusiveness,
merit-based hiring and recognition, and providing
safe spaces for people of all backgrounds and career levels in STEM
disciplines. An environment of trust and diversity enables scientific
creativity, supporting the scientific advancements discussed at this
conference. To hasten the creation of an inclusive and equitable community
within Heliophysics, we have created the Equitable Letters for Space Physics
effort, which is working to encourage merit-based recommendations and
nomination in the space physics community by providing resources and reviews.
We are currently looking for reviewers to help with the upcoming deadlines
for recommendation letters and nominations. To find out more about our vision
for 2050 and resources and how to become involved please see our poster and
visit https://equitableletterssp.github.io/ELSP/.
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Clark G. Li W. Paranicas C. Turner D. L. Kollmann P. Cohen I. J. Roussous E. Nenon Q. Mauk B. H. Jaynes A. N. Blum L. W. Smith H. T. Ukhorskiy A. Y. Hospodarsky G. B. Sorathia K. Dunn W. R. Marshall R. A. Li X.
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JUGGERNOT: A Mission to the
Solar System’s Greatest Particle Accelerator [#2124]
In this
presentation, we discuss a Heliophysics mission concept that will address the
mysteries of particle acceleration within the full range of Jupiter’s
radiation belts. The concept is called JUGGERNOT — or JUpiter’s
Global maGnetic Environment and RadiatioN
ObservaTory — and is a low inclination Jupiter
orbiter with a perijove inside 2 Jovian radii (RJ)
and an apojove >= 30 RJ outfitted with a novel scientific payload that is
specifically focused on characterizing the >> 1 MeV ion and electron
core radiation belt populations, the lower-energy seed populations, and their
interactions within Jupiter’s material-dominated space environment via global
imaging of X-rays. In addition, the concept carries instruments that will
make key measurements of the thermal plasma, fields, and waves to understand
the seeding and acceleration mechanisms. Why should Heliophysics send a
mission to Jupiter? Jupiter’s space environment is unlike any others in the
Solar System. It sets itself apart by having the fastest rotation, the
strongest magnetic field and the most powerful aurora and most intense
radiation belts. Jupiter is also the only planet within the Solar System that
emits synchrotron radiation, which puts it in league with astrophysical
systems. Embedded in Jupiter’s inner magnetosphere are a
number of moons that also have their unique qualities, e.g., from Io’s
extreme volcanic activity and Europa’s sub-surface ocean to the irregular
inner satellites such as Amalthea; those moons shape the radiation belts via
an intriguing combination of source and loss processes. Together, these
various aspects provide a unique natural laboratory that can be exploited
with the goal of unlocking the secrets of universal acceleration processes by
exploring what drives the most intense radiation belts in the Solar System.
This mission concept addresses a longer-term science strategy that the
community is advocating for Heliophysics to adopt in the next decade. Namely,
missions that broadly advance Heliophysics by addressing knowledge gaps
across NASA’s science divisions. Jupiter is the stepping
stone to understanding particle acceleration between Earth, the rest
of the Solar System and in more extreme astrophysical domains.
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Cohen C. M. S. Berger T. E. Desai M. I. Duncan N. Ho G. Maruyama N. Pulkkinen T. I. Szabo A. Vourlidas A. Zesta E. Zhang Y.
|
Living With a Star
Architecture Committee Seeks Input [#2167]
In
response to the recommendations of the 2013 National Academies of Sciences,
Engineering, and Medicine’s Decadal Survey for Solar and Space Physics and
the subsequent 2019 Midterm Decadal Survey Assessment, the NASA Heliophysics
Division (HPD) has begun to re-evaluate the Living With a Star (LWS) mission
line. As part of the evaluation, the HPD has solicited the broad heliophysics
community and formed a 10-member committee to 1) assess the current state of
the mission aspect of the LWS program; and 2) propose a future LWS program
architecture. Mirroring the successful LWS Focused Science Topics structure,
the committee is working on creating Focused Mission Topics (FMTs) that
address the strategic science areas which guide the LWS program. The
committee seeks comments and input from the science community and will enable
several avenues to do so; Heliophysics 2050 is an excellent example of one of
those channels for input. We encourage scientists to reach out to the
committee members present at the meeting, engage in discussion at the poster
presentation, and avail themselves of other opportunities to provide feedback
in the future. The committee’s final report will be completed by the end of
the year and published in time to be useful as input to the 2024
Decadal Survey.
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Cohen I. Rymer A. Turner D. Gkioulidou M. Clark G. Kollmann P. Vines S. Allen R. Westlake J. Nikoukar R. Regoli L. Brandt P. Mandt K. Azari A. Bagenal F. DiBraccio G. Garcia-Sage K. Gershman D. Ebert R. Liemohn M. Slavin J. Paty C. Roussos E. Lamy L. Halekas J. Jaynes A. Sulaiman A. Szalay J.
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The Case for Studying Other Planetary Magnetospheres
and Atmospheres [#2117]
One of
the best ways to learn about our world and where it resides on the planetary
spectrum, is by studying the diversity of magnetospheric and atmospheric
systems and processes that exist on our neighboring worlds. The diverse
planetary systems within our solar system and beyond provide crucial data
points that can provide deep insight into the fundamental physics that govern
our local Heliophysics environment. To maximize opportunities for discovery
and truly advance our understanding, we need to address programmatic
restrictions and community stove-piping that often limit Helio-funded
opportunities and aspirations to study key fundamental processes to
relatively few targets, i.e., Earth, the Sun, solar wind, and local
interstellar space. The solar system is ripe with compelling space physics
targets. Mercury’s Earth-like magnetosphere is possibly the most
solar-wind-driven and causes intense plasma interactions with the planet’s
surface. Venus hosts a thick atmosphere and substantial ionosphere, without
global-scale rotation, but no strong internal magnetic field. Mars presents
yet another distinct magnetospheric category in the inner planets, lacking a
global intrinsic field but with small, localized patches of surface
magnetization in its crust. At each of the terrestrial planets, the solar
wind coupling to the ionosphere and atmosphere is unique and requires
observations to characterize and ultimately quantify the key controlling
factors. In the outer solar system, the Giant planets present their own
unique heliophysics-relevant questions. Saturn and Jupiter both contain
volcanically active moons that provide significant sources of neutral gas and
plasma to their magnetospheres. These worlds and their moons raise important
questions about sources and losses of magnetospheric plasma, not to mention
to role of icy rings and dust particles. Fundamental questions remain about
how magnetospheric plasma is transported, sourced, and lost and how solar
wind-magnetosphere-atmosphere coupling is governed by the asymmetric
magnetospheres of Uranus and Neptune. Likewise, potential ocean world moons
like Triton and Titan host fairly thick atmospheres
and ionospheres that reside within complex magnetospheric systems.
There are multiple avenues for the Heliophysics community explore these
worlds, including enhancing cross-Divisional collaborations and broadening
programmatic scopes, and great examples of recent, past, and ongoing
successes in such endeavors.
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DeJong A. Gallardo-Lacourt B. Halford A. Robinson R.
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Best Practices for Supporting Soft
Money Scientists [#2027]
The
pathway to 2050 will undoubtedly involve a global community of scientists,
linked together virtually and able to exploit emerging technologies for
collaboration and resource sharing. This will overcome the boundaries
separating scientists with various physical workplaces, employment
affiliations, and home-life situations. This will expand the participation of
what is now referred to as ‘soft-money’ scientists. Even now, most
Heliophysics scientists will be a soft money scientist at some point in their
career. With university faculty and government civil servant positions being
limited, some may find themselves spending most, or all, of their careers as
soft money scientists. Our goal is to identify ways that can make this type
of career path more fulfilling and successful. We began our study by
investigating the NASA GSFC Heliophysics Science Division (HSD), as a large
portion of its work force are soft money contractors. We interviewed both
NASA contractors and soft money scientists from other institutions to
understand what practices has and has not worked for them. We have found that
there are many universal problems facing the soft money scientist that need
to be addressed as a community. The goal is to put together a living document
of the best practices for our community that can be applied at any type of
institution to better support soft money scientists. We will present some of
our findings and solutions that we hope to implement in the HSD at
NASA GSFC.
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Dorfman S. Carter T. A. Fu X. R. Chen C. H. K. Vincena S. T. Tripathi S. K. P. Pribyl P. Boldyrev S. Franci L. Lichko E.
|
Alfvén Wave Processes in Heliophysics:
The Role of Laboratory Experiments [#2135]
Today’s
most advanced multi-spacecraft missions (MMS, THEMIS, Cluster) come with
inherent limitations: they only allow
exploration of naturally occurring plasmas, lack control over the plasma
parameters, and cannot distinguish whether the observations are due to local
effects or variations in the initial and boundary conditions. Controlled
laboratory experiments, which do not have the same limitations, represent a
crucial tool for complementing space-based investigations. In the laboratory,
it is possible to focus on key Heliophysics-relevant physical processes under
well-controlled conditions in a real plasma. For example, on the Large Plasma
Device (LAPD) at UCLA, Alfvén waves with well-defined frequencies and wave
numbers may be launched in configurations tailored to various non-linear
processes. Experiments along this line include:
1) Alfvén wave parametric instabilities represent a possible cause of coronal
heating (acoustic modes may directly heat ions) and a potential intermediate
mechanism for the transfer of energy to small scales in the solar wind. LAPD
experiments show the first laboratory observation of an Alfvén wave
parametric instability, including features not yet predicted by theory
[Dorfman and Carter, PRL 2016].
2) The presence of cold ions in the magnetosphere makes a reliable
measurement of the ion mix difficult. An alternate method may involve
measurements of non-linearly interacting Alfvén waves launched from
spacecraft. Recent LAPD experiments launch two Alfvén waves in a
multi-species plasma to demonstrate the feasibility of this technique [Fu and
Dorfman, In Preparation].
3) In the solar wind, there is excess energy in the magnetic fluctuations
compared to the velocity fluctuations [Chen, et. al. 2013]. However, for
linear Alfvén waves this “residual energy” is zero. LAPD experiments starting
from two counter-propagating Alfvén waves aim to
probe the nonlinear source of this residual energy.
In all of these cases, which have applications from the magnetosphere to the
solar surface, the range of normalized plasma parameters accessible in LAPD
allow for the study of key physics in the relevant heliospheric regimes.
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Espley J. R. Gruesbeck J. R. DiBraccio G. A.
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The Martian Hybrid Magnetosphere: A Natural Plasma Laboratory [#2004]
The
interaction of the solar wind with the martian ionosphere creates what is
often called an induced magnetosphere. The presence of localized strong
magnetic field regions in the martian crust complicates this interaction,
creating localized mini-magnetospheres. This
combination of a global induced magnetosphere with crustal intrinsic
magnetism is called a hybrid magnetosphere. This combination of magnetospheric
and ionospheric regimes creates a rich natural plasma laboratory at Mars.
Specifically, Mars has an abundance of asymmetrical and time-variable plasma
boundaries, wave-particle interactions, reconnection regimes, and space
weather responses. Looking to the future, Mars can be a place where we test
observational strategies and theoretical understandings of plasma physics as
applicable across the heliosphere. Furthermore, a detailed understanding of
the space weather environment at Mars will become increasingly important as
humanity continues its robotic and potentially crewed exploration
of Mars.
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Fox W.
Schaeffer D. B.
|
Opportunities for Laboratory Experiments on Heliospheric
Plasma Physics [#2149]
Recent
experimental capabilities in laser-produced plasmas offer significant
opportunities to study plasma physics processes relevant to heliophysics,
including energy conversion processes including magnetic reconnection,
magnetized collisionless shocks, kinetic plasma
instabilities, and magnetized plasma turbulence. Experiments can probe
consequences of these processes including plasma heating and particle
energization and acceleration. The
high laser energy now available allows high-temperature, low collisionality plasmas to be produced which are much
larger than plasma kinetic scales (ion gyro-radius and ion inertial length),
with imaging diagnostics which span the global to the kinetic scale. We will highlight recent results and
propose possible topics of partnership for future experiments.
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Garcia-Sage K. Halford A. Domagal-Goldman S. Kopparapu R. Young K. Mandell A. DiBraccio G. A. Yue J. Cohen I. Farrish A. Gershman D. Glocer A.
|
Enabling Cross-Heliophysics and
Cross-Divisional Research [#2108]
Nature
often does not provide us with clear boundaries — the atmosphere extends into
the ionosphere, the ionosphere extends into the magnetosphere, and processes
that begin at the Sun reach every planet in our Solar System. Heliophysics is
tied to each of the other three science divisions at NASA and reaches across
divisions and directorates at NSF. The physical dynamics studied by the
heliophysics community are found throughout the universe. In contrast to this
connectedness throughout heliophysics and with other branches of science, our
funding typically acts as if clear physical boundaries exist.
While there are real needs and reasons for delineated funding between and
within science divisions, additional mechanisms must simultaneously exist to
help overcome the roadblocks that ensue. These mechanisms must be scaled to
the various ways that research is carried out, from small ROSES grants and
even internal institutional funding to mission-scale and large team efforts.
Past efforts to carry out cross-disciplinary research of this nature include
highly successful missions (e.g. Parker, MESSENGER,
Juno, MAVEN), NASA/GSFC collaborations (e.g. the SEEC Exoplanet and EIMM
Heliophysics/Planetary collaborations), and NASA Agency-level Astrobiology
programs. However, dedicated sustained funding to carry out such efforts is
still lacking. The NSF 10 Big Ideas initiatives and NASA’s DRIVE Center
efforts are a step in the right direction to providing funding dedicated
toward large-scale cross-disciplinary and cross-heliophysics efforts,
respectively.
Additional support is needed for researchers to pursue smaller-scale
interdisciplinary collaborations. These smaller collaborations would provide
the benefit of promoting equity by enabling institutions and individuals that
are not positioned to respond to large-scale efforts to carry out
interdisciplinary work. They also would serve as a way to
incubate ideas that may not be ready for large-scale efforts, ultimately
improving the quality and diversity of interdisciplinary efforts. When
dedicated funding streams enable cross-disciplinary science, it is likely
that individual institutions will follow suit, establishing their own ways to
promote connections and conversations between departments and labs. We
encourage successful interdisciplinary science teams to contribute lessons
learned and best practices, in order to assist
scientists in spanning these divides and advancing equity in science through
such efforts.
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Gibson S. E. DeForest C. Attie R. Gallardo Lacourt B. Gilly C. R. Provornikova E.
Viall-Krepko N. Cranmer S. Thompson B. J. Malanushenko A. Webb D. de Koning C. Desai M.
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The PUNCH Associate Investigator (AI) Program [#2082]
PUNCH
(Polarimeter to UNify the Corona and Heliosphere)
is an in-development NASA mission that will image the outer corona and solar
wind throughout the inner heliosphere. PUNCH has instituted a program to
recognize and encourage early-career scientists working with the Science Team
on problems that support and enhance mission science. PUNCH Associate
Investigators (AIs) pursue science projects with mentorship from PUNCH coI(s), attend team meetings, participate in PUNCH
working group activities, and present at PUNCH science meetings. They act as
liaisons, communicating PUNCH science to the broader community and community
needs back to the project. In this way, they help grow the PUNCH user base, and also benefit from the career-enriching experience of
being embedded in a NASA mission at an early stage of their careers. In this
poster, we introduce the 2021 PUNCH AIs and their science, and discuss the
broader context of this program with regard to
involving early career scientists in NASA missions in order to grow a diverse
cohort of potential future PIs.
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Gibson S. E. de Toma G. Qian L. Kolinski D. Hewins I. Allen R. Thompson B. Emery B. Gasperini F. Hudson M. Aryal S. Kozyra J.
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Whole Heliosphere and Planetary Interactions
(WHPI): A New Initiative on
Solar Minimum [#2040]
The
Whole Heliosphere and Planetary Interactions (or WHPI) is an international
initiative focused around the solar minimum period,
which aims to understand the interconnected Sun-heliospheric planetary
system. WHPI follows two similar initiatives during previous solar minima.
With each initiative we have expanded our scope, from sun/solar wind during
the Whole Sun Month of 1996, to sun/solar wind-geospace
science during the Whole Heliosphere Intervals of 2008-2009, and now with the
study of sun/solar wind/planetary interactions during the Whole Heliosphere
and Planetary Interactions initiative. The success of these efforts relies on
a broad participation of scientists worldwide and across disciplines.
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Glesener L. Allred J. Caspi A. Christe S. D. Guidoni S. Kerr G. Krucker S. Reeves K. Shih A. Y. Veronig A. Vievering J. T.
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Understanding Stellar Flares by Observing the High-Energy Sun [#2153]
Understanding
high-energy aspects of flaring activity on the Sun can help to understand the
capability of other stars to support life or to wipe it out (or both!). This
includes understanding the effects of solar and stellar flares on planetary
atmospheres, such as radiation level changes (particularly high-energy
photons and energetic particles) at the surfaces of planets in the habitable
zone. To better merge what is known about flares on the Sun and on other
stars, and their effects on other planets, multidisciplinary efforts will be
needed that span solar, heliospheric, magnetospheric, ionospheric, planetary,
and stellar physics. High-energy measurements will play a key role. Within
the area of solar flare investigation, efforts are needed to better
characterize the entire flare frequency distribution and place these within
the context of flare distributions measured on other stars. This includes
studying large flares that could cause abrupt damage all the way down to
nanoflares, which could be influential due to the power in numbers.
High-energy measurements of flares (especially those observed in hard and
soft X-rays, EUV, and radio) are among the measurements that can be compared
with stellar studies. It should be noted that stellar flares often do not
have the multiwavelength coverage than solar flares do, and non-thermal
stellar flare observations are extremely rare. A concerted effort should be
made to garner thorough, multiwavelength studies of individual high-energy
solar flares and of solar flare distributions, including up to nonthermal
energies, along with the development of models that can be applied to other
stars (with tuned parameters and with constraints from stellar observations).
The development of analysis methods that can be utilized for both solar and
stellar measurements is also required.
Lastly, an effort will need to be made to bridge heliophysics and
astrophysics communities in order to leverage the
full capability of this line of inquiry.
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Goodwin L. V. Bhatt A. Bossert K. Jones M. A. Jr Mcgranaghan R. M. Oberheide J.
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Long-Term Vision for Heliophysics: A Summary of Thoughts from the
CEDAR Community [#2100]
The
Coupling, Energetics and Dynamics of Atmospheric Regions (CEDAR) workshop is
an annual meeting sponsored by the National Science Foundation. Although it
only represents a portion of the broader heliophysics community, it is
instrumental in advancing science goals related to the Earth’s upper
atmosphere and understanding the role space weather plays in our modern
lives. At the 2020 CEDAR workshop, a “Long-Term Vision” session took place
that identified the directions in which the CEDAR community wishes to see
itself and the heliophysics community grow and change. During these
discussions, a desire for the following transformative changes were
vocalized: 1) in keeping with CEDAR’s
strategic vision (which mentions that what “has emerged from CEDAR research
is the recognition that many of these natural coupling processes are linked
through system processes that demonstrate complexity”), the creation of
stronger collaborations between different physics communities (e.g.
exoplanets, planetary atmospheres, troposphere, comparative atmospheres,
etc.) and STEM communities (e.g. mathematics, computer science, engineering,
etc.) to develop science goals with complementary observations and models, 2)
the consideration of how space science plays a role in tech and industry
communities and re-evaluating how we collaborate with those groups, 3)
improved inclusion of citizen science by identifying groups already engaged
in heliophysics research and the creation of well-designed citizen science
projects with ample funding for all pieces of the project (e.g., science,
software, people/volunteers, education, and data storage),4) broadening
participation in science and improving the diversity, equity, and inclusivity
of heliophysics,5) more adequately preparing students and heliophysics for
the future of science, such as through discussions of data science and
machine learning,6) raise awareness of the relevance of heliophysics to
society and more adequately address the goals of society by understanding its
needs, improving the bridge from fundamental research to applied research,
and improving the feedback between society and scientists. These themes, as
well as additional thoughts from the CEDAR community, will be discussed further
in this poster.
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Halford A. J. Garcia Sage K. Thompson B. Kellerman A. ISWAT 01-01 Team
|
Documenting the Pathway into the Future with Application
Usability Levels [#2054]
Nature
often does not provide us with clear boundaries — the Earth’s Atmosphere
extends into the ionosphere. The Ionosphere extends into the magnetosphere,
etc. And the physical dynamics observed across these regions are found on
other planets, other solar systems, and throughout the universe. In contrast,
our funding for research often does act as though clear boundaries exist.
While there are real needs and reasons for this delineated funding, it does
hamper interdisciplinary through transdisciplinary collaborations. Many have
recognized the issues and roadblocks which have arisen from this disconnect
and we hope that by 2050 solutions and mitigations will have been adapted.
Here we suggest one possible solution that establishing a ‘Center for Cross
Division Science’ that consists of area experts from different departments
from an academic institution would spur interconnectivity and conversations
that promote cross-division/cross-center science collaborations. We also
welcome to develop other possible avenues for promoting cross-division
interactions, identify best practices and lessons learned, for how to span
these institutional and divisional divides.
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Halford A. J. Garcia-Sage K. Samara M. Welling D. Walsh B. Kirk M. S. F. Thompson B. J. Rowland D. Bain H. M. Bard C. Gabrielse C. Liemohn M. W. Breneman A. W. Rivera Y. J. Lejosne S. McGranaghan R. M. MacDonald E. Turner D. Allen R. C. Jaynes A. N. Vines S. K. Nikoukar R. LLera K. Stawarz J. E. Gingell I. Genestreti K. J. Blum L. Filwett R. J. Saikin A. A. Sibeck D. Vievering J. Higginson A. K. Mostafavi P. Hartinger M. D. Atz E. A. Greeley A. D. Willson L. B. III Bortnik J. Masongsong E. V. Tu W. Kosar B. Brandt L. Clark G. Sorathia K. Gkioulidou M. Regoli L. Merkin S. Rymer A.
Cohen I. Claudepierre S.
Maute A.
Mitchell R.
Giles B. Knudsen D. Cattell C. Kistler L. Lyons L. Spann J. Li W. Chen L.-J. Woodroffe J. Argall M. R. Savage S. Dorelli J. C. Pfaff R. Zettergren M. Jahn J.-M. Arge C. N.
Zesta E. Glesener L. Turner N. E. Mirizio E. R. LeMay M. Bonnell J. Athiray P. S. Pulkkinen T. I. Lepri S. T. Ridley A. J. McHarg M. G. Malaspina D. Erlandson R. Sotirelis T. S. Gonzales E. V. Klenzing J. Thomas B. Young C. A. Collado-Vega Y. Sittler E. C. Mays M. L. Katus R. M. DeJong A. D. Habash Krause L. Kepko L. Klimchuk J. Whittlsey P. L. Shumko M. Lynch K. A. Mandt K. Domagal-Goldman S. D. Young K. Cash M. D. Marbel A. R. Raftery C. L. Keesee A. M. Kerr G. S. DeForest C. E. Seaton D. B. Milic I. Cheung M. C. M. Bowen T. A. Badman S. T. Gallardo-Lacourt B. Korreck K. E. Mason J. P. Zou S. Moldwin M. B. Viall N. Alterman B. L. Caspi A.
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Enabling and Advancing Scientific Innovation
Through Cultivating a Collaborative, Inclusive, Diverse, and Safe
Community Culture [#2130]
This
workshop asks us to dream big about what our field, our community, will be in
2050. Specifically, we have been encouraged to think innovatively about what
science questions we hope to address within 30 years. We believe a uniquely
fundamental question will drive those science innovations: What research environment and community
will we build in the next 30 years? The most innovative scientific ideas and
discoveries will come by cultivating a safe, inclusive, diverse, accessible,
and collaborative environment. This environment will also strengthen all
types of collaborations from intra- to trans-disciplinary - furthering the
potential innovations. If we ignore this critical aspect of science, we will
maintain the same issues our field is experiencing regarding diversity,
retention, and succession, all of which inhibit true innovation. Some
activities to cultivate an equitable environment have started through
organizations like NASA, AGU, NSF, and others. We will pose additional clear
steps that we can take now so that future scientists born today will enter into an inclusive field in 2050. The first step is
to embrace and employ the best practices laid out in the National Academy’s
Science of Team Science (STS) report and to continue studying their impact
and update them as our understanding improves. The next step is to ensure
equity and access across the field through adopting open science practices
whenever possible. We can integrate the lessons learned from the past year
during pandemic-imposed telework to better enable virtual participation in
workshops and encourage collaboration across geographically dispersed teams.
This past year has also highlighted many roadblocks that inhibit some of
these best practices, such as a lack of access to and affordability for some
collaborative tools/workshops. What is presented within this poster is just a
small step forward along the path needed to establish an inclusive,
equitable, and anti-racist scientific field by 2050. As we grow and learn as
a community, we will identify new paths forward, and we hope to encourage
humility, ongoing self-reflection, respect, and empathy. By establishing and
instituting actionable paths forward to foster these traits, our community
will ensure that our field keeps a steady eye on how we collaborate and work
with each other to ensure that the best ideas are elevated. Ultimately, we
can better learn from each other and innovate within this
collaborative environment.
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Harman A. S. Mastandrea J. Paul M. V.
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The Pragmatic Interstellar Probe Mission Concept Study
Online Library [#2038]
The
Pragmatic Interstellar Probe Mission Concept Study is compiling an online
library of articles, papers, presentations, study reports, and annotated
bibliographies for the scientific and engineering communities, and beyond.
This material is relevant to the development of the mission concept. At the
conclusion of the concept study, the website will be a storehouse of
information available to the public. In presenting this library, the study
team hopes to receive feedback on how to improve its utility.
The materials library is available to the public on the Pragmatic Interstellar
Probe Mission Concept Study’s website (http://interstellarprobe.jhuapl.edu/).
When possible, full presentations or papers are made available. If materials
are copyrighted, a citation is given or a link to where they can be accessed
is provided.
Several types of content are located on the website. First, the site pages
themselves are populated with content from reports and presentations for the general public. This ‘top level’ content is navigable and
organized to provide an overview of the science and engineering aspects of
the study. Another section is a library of material from events and meetings
presented by the study team. This includes content such whitepapers (e.g.,
decadal surveys, Helio 2050), and session materials
from various meetings. Specially developed collections include a webinar
series with 14 episodes and counting, covering a range of relevant topics.
A number of audiences for this material have been
identified, and the study team is soliciting feedback to ensure that this
resource is useful for all of them. The first is engineers and scientists who
can use this material to support their own work and research. Second, are
students, both at undergraduate and graduate levels. An effort is currently
underway to identify how best to present this information and make it useful
for those who are just starting their research careers. A related audience is
teaching professionals, who could use it to develop lesson plans about a
variety of space science and engineering topics. Another important group are
legislators. This website could be a tool they can use when considering the
priority that should be given to a potential Interstellar Probe Mission,
which would support vital science objectives for decades to come. This list
of potential uses for the website is by no means exhaustive,
but includes the key stakeholders who could most benefit from
this resource.
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Jaynes A. N. Cohen I. Ridley A. Erickson P. J. Alterman B. L. Wilson L. B. III Halford A. J. McGranaghan R. Filwett R. J. Regoli L. H. Gasperini F. Llera K. Nikoukar R. Hartinger M. D. Stawarz J. E. Ferdousi B. Argall M. R. Bortnik J. Goodwin L. V. Turner D. L. Claudepierre S. Keesee A.
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An Open-Access Community: Why We Need to Prioritize Our Scientific
Environment as a Welcoming Space [#2140]
Historically
marginalized groups are disproportionately represented in the US geosciences.
This is unacceptable. As Heliophysicists, we
publish open-access articles in our peer-reviewed journals
and we push for transparency in data and simulations used in these
manuscripts. We need to be equally emphatic about the access to our
communities from historically marginalized groups. It’s
not only the right thing to do: the
very future of our science depends on how well we can provide a supportive
and safe environment for every scientific mind.
The incoming generations of students and early career professionals are much
more interested in the diversity, equity and inclusion climate of their
workplace than previous generations. These issues are increasingly important
to the younger generations when deciding (1) where to go to school; (2) where
to work; and (3) what field to specialize in. Coupling this with data showing
a drop-off in college-age US residents (due to the population bust) and we
are competing for fewer students who hold clear opinions about what values
they want their workplace and career to uphold. Thus, if we want to retain
scientists and build our field we must work on upholding and implementing
these values. In the geosciences, there has been no advancement in
representation of racial and ethnic groups for 40 years. This means
Heliophysics is not recruiting the best talent. It also means that the
discipline itself is failing to represent the community that funds it and
benefits from its work. This is unacceptable and we, as Heliophysicists
and leaders, must implement open-access principles across our discipline. The
cultural transformation must come from changes on both sides: individually
and from leadership. We cannot be inactive any longer. We will outline some
examples of change that can be initiated to foster anti-racism, radical
inclusion, and respectful spaces for all gender identities and sexualities.
The idea of identity is naturally intersectional, and our community must be
welcoming and accessible for all people, including those who identify as
neurodiverse, experience disability, and struggle with mental health. New and
ongoing initiatives to combat bias and harassment in our community are just
the start – we need everyone to commit to these principles and agree to
support each other going forward. The future of Heliophysics depends
on it.
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Ji H.
Karpen J. 106 Co-Authors
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Major Scientific Challenges and Opportunities in Understanding Magnetic
Reconnection and Related Explosive Phenomena in Solar and
Heliospheric Plasmas [#2133]
Magnetic
reconnection underlies many explosive phenomena across a wide range of
natural and laboratory plasmas. It plays a pivotal role in electron and ion
heating, particle acceleration to high energies, energy transport, and
self-organization. In this presentation, we present a white paper
(https://arxiv.org/abs/2009.08779) submitted to Helio2050 workshop to
describe major scientific challenges and opportunities in coming decades. New
capabilities in theory, simulations, observations, and laboratory experiments
provide exciting opportunities to solve the grand scientific challenges in
understanding magnetic reconnection and predicting space weather events.
Success requires enhanced and sustained investments from funding agencies,
interagency partnerships, and close collaborations among solar, heliospheric,
and laboratory plasma communities.
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Johnson L. McKenzie D. Newmark J. Carr J. Turse D.
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Solar Sail Propulsion — Accessing New Vantage
Points for Heliophysics [#2026]
Many
high-priority Heliophysics science goals identified in the last two decadal
surveys remain unaddressed due to the difficulties in obtaining the required
observations. Solar sails provide extremely large ΔV (potentially many
10s of km/sec), enabling missions to new vantage points and allowing
compelling science questions to be addressed, including:
• What is the relationship between the dynamics and magnetism of the Sun’s
polar regions and the evolution of solar activity and the solar cycle?
• What are the physics of the propagation and evolution of the large-scale
structures in the heliosphere?
• What are the physical processes that control the transport of mass and
energy through the Earth’s magnetosphere in response to solar and terrestrial
inputs?
Destinations enabled by solar sails that are not practically implementable
using conventional rocket propulsion include sustained observations away from
the Sun-Earth line (SEL); sustained sub-L1 station keeping for improving
space-weather monitoring, prediction, and science, and supporting human
spaceflight crew safety and health needs; sustained in-situ Earth magnetotail
measurements; those that require a high inclination solar orbit; low perihelion
and out-of-the-ecliptic missions; multiple fast transit missions to study
heliosphere to interstellar medium transition; other novel orbits not easily
accessible using conventional propulsion, like near-continuous observations
over the poles of Earth or Mars.
Sails are relatively low-cost to implement and the continuous solar photon
pressure provides propellantless thrust to perform
a wide range of advanced maneuvers, such as to hover indefinitely at points
in space, or conduct high DV orbital plane changes. The NASA MSFC Solar
Cruiser mission will demonstrate solar sail technology for use in
implementing these future Heliophysics missions during its 2025 flight
utilizing a ~1653 m2 solar sail containing embedded reflectivity
control devices and photovoltaic cells. The mission timeline includes
deployment of largest sail ever flown, validation of all sail subsystems,
controlled station-keeping inside of the Sun-Earth L1 region, demonstration
of pointing performance for science imaging, and an increase in heliocentric
inclination (out of the ecliptic plane). Solar sail propulsion will provide
an enabling capability for future Heliophysics missions, allowing scientists
to address multiple outstanding science questions between now and 2050
and beyond.
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Johnson P. A. Johnson J. C. Mardon A. A.
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Corona Discharge-Mediated Ionic Wind Powered Propulsion [#2010]
Ionic
winds are an electrohydrodynamic phenomenon which is a form of air movement
resulting from the collision of neutral and charged molecules subjected to an
electric field. The possibility that they can be harnessed for the propulsion
of aircrafts has been widely explored, however the feasibility remained
untested and unclear. Recently, a proof-of-concept prototype for ionic wind
propulsion has overcome limitations which were believed to make ionic
wind-driven propulsion unviable. We propose ionic wind propulsion as an
achievable means of propulsion for aircraft in the lunar and extra-celestial
atmosphere. We assessed this proof-of-concept design and critically evaluated
it against current understandings of principles established to affect
propulsion systems in space. We also provide a summative analysis based on
existing knowledge about propulsion systems in space, particularly aircraft
transport.
A challenge for ionic wind propulsion to be maintained is generating
sufficient thrust while ensuring low aircraft drag and weight. This means
overcoming the thrust-to-power ratio and thrust density, which has been
deemed unrealistic until recently. However, the overall efficiency of such a
propulsion system is poor. There exists a threshold thrust-to-power ratio and
thrust density using corona discharge and the tradeoff between the two
variables result in inequality constraints and a lower efficiency. While an
ionic wind propulsion system appears to be a feasible alternative to
aircrafts fueled by combustion on the moon. This theory remains untested and is based on the assumption that the lunar or planetary
atmosphere is able to support such a system. There is no knowledge about the
range for flight or its feasibility on the surface of different celestial
bodies. The use of ionic wind propulsion for aircraft transport in space is
conceivable although it is presently theoretical. With the current advancements
in technology, such a propulsion system not only seems much more feasible
outside of Earth, it also offers a promising means
of transport in the future for humans habitation on the moon or
other planets.
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Kollmann P. Turner D. L. Roussos E. Nenon Q. Clark G. Cohen I. Li W. Sulaiman A.
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Jupiter’s Radiation Belts as a Target for NASA’s
Heliophysics Division [#2033]
NASA’s
heliospheric division studies “the Sun, the heliosphere, and Earth’s
magnetosphere and... universal plasma phenomena”. We will argue that
Jupiter’s magnetosphere, radiation belts, and near-space environment should
be considered as relevant targets for NASA’s Heliophysics missions. Jupiter’s
magnetosphere covers all universal processes called out in the 2013 Decadal.
Space plasma physics at planetary systems is much more relevant to the
defined focus of NASA’s Heliophysics division than for the core sciences of
the planetary division.
Jupiter’s giant magnetosphere hosts a wealth of particle species and charges
subject to processes that can be studied with less ambiguity relative to
Earth thanks to spatial unmixing. This makes Jupiter an ideal laboratory to
investigate a wide range of space plasma processes. Its magnetosphere
continuously accelerates particles to higher energies than what is even
reached during extreme space weather events. Jupiter covers such an immense
parameter range in particle energies, magnetic field, and waves that it can
bridge the in-situ study of magnetospheres and the remote observation of
extrasolar systems like supernova remnants.
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Lazio T. J. W. Arnold B. W. Dowen A. Z. Levesque M. E. Boyles C. A. Giovannoni B. J. Berner J. B. Smith A. E. Lichten S. M. Castano R.
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Enabling Richer Data Sets for Future Heliophysics Missions [#2025]
A
consequence of our improved understanding of the Sun and the heliosphere is
that future Heliophysics missions must envision richer data sets. NASA has
enabled an infrastructure that permits future Heliophysics missions to deliver
richer and more complex data sets. Importantly, this infrastructure has been
and is being implemented without requiring funding from NASA’s Heliophysics
Division, but it is available to future Heliophysics missions.
NASA’s Deep Space Network (DSN) is a series of large, sensitive antennas
distributed around the world and that are integral to Heliophysics missions,
such as STEREO, Parker Solar Probe, and the Sun Radio Interferometer Space
Experiment (SunRISE). Among the various
improvements planned for the DSN in the next decade are (i) Increased
capability at higher frequencies, which enables higher data rates by virtue
of larger bandwidths available (including 26 GHz for missions at Earth-Sun L1
point); and (ii) Additional antennas at each of the three Complexes.
NASA’s Advanced Multi-Mission Operating System (AMMOS) is a suite of software
tools and services designed to facilitate the rapid construction of low-cost
and reliable mission operations and data processing capabilities for robotic
missions. Various AMMOS capabilities are used by numerous Heliophysics
missions, and improvements planned for the AMMOS in the next decade include
(i) A Reference Mission System enabling the rapid deployment of a ground
system by providing a comprehensive and integrated set of AMMOS products;
(ii) An implementation for the “cloud,” allowing processing without requiring
dedicated on-site hardware; and (iii) Enhanced data visualization, allowing
both rapid assessment of spacecraft health and initial capabilities to examine
science data before higher level data products are produced.
Part of this research was carried out at the Jet Propulsion Laboratory,
California Institute of Technology, under a contract with the National
Aeronautics and Space Administration.
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Mandt K. E.
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Advancing Space Science Requires NASA Support
for Coordination Between the Science Mission Directorate Communities [#2061]
There
is growing awareness that advancing science requires greater coordination and
collaboration between the communities represented by the NASA Science Mission
Directorate (SMD) Divisions. We outline specific steps to address this
growing need but note that the only way that this effort can be successful is
if it is initiated within NASA and is supported through directed resources provided
by NASA to the community.
The Exoplanet Science Strategy describes exoplanet science as an “avalanche
of unexpected discoveries,” and outlines how detecting life on an exoplanet
“will happen only when researchers bring together the combined insights of
astrophysicists, planetary scientists, Earth scientists, and heliophysicists, and provide them the resources to
collaborate.” This finding demonstrates awareness that progress is limited by
the lack of pathways and resources for coordination between different
research communities. Historically, the SMD Divisions have had limited
freedom to coordinate resources (e.g. funding,
mission observations) to address science objectives that cross Divisions. The
need for broadened coordination between Divisions is most obvious and
immediate for exoplanet characterization. The exoplanet community is
predominantly made up of stellar astrophysicists because this expertise is
essential for enabling detections. However, characterization of exoplanets
requires understanding in situ planetary and heliophysics data in appropriate
context.
Recommendations for NASA: There are
several steps that NASA could take:
(1) Assign cross-division representatives to the NASA SMD Advisory
Committees; (2) Request cross-division representatives serve on decadal
survey committees; (3) Incorporate cross-division objectives into active and
future missions; (4) Establish additional formal coordination networks like NexSS; (5) Fund cross-division meetings between the
communities; (6) Actively work to eliminate discrimination and harassment,
which are barriers to a socially healthy community.
Recommendations for the community: There are several steps that the space
science communities can take: (1)
Inventory community needs; (2) Advocate for observations that benefit
multiple communities; (3) Actively work to eliminate discrimination and
harassment, which are barriers to a socially healthy community.
These recommendations are described in detail in a white paper available
here https://docs.google.com/document/d/1XTx9G7ym9wf8SWH0-pAPXtDKOeWQII3GBV8N2jagD40/edit#.
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McGranaghan R. M. Borovsky J. Chapman S. Donovan E. Semeter J. Valdivia J. Uritsky V. Wing S. Johnson J. Verkhoglyadova O. Consolini G. Materassi M. Thayer J. Dorelli J.
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Complexity Heliophysics: A New
Science that Transcends the Previous Boundaries of Our Field [#2125]
“The
[21st] century will be the century of complexity.” - Stephen Hawking
Heliophysics processes span at least 15 orders of magnitude in space and
another 15 in time. The reaches of our science go well beyond our own solar
system and Earth’s space environment to touch planetary, exoplanetary, and
astrophysical domains. The history of Heliophysics has, like many sciences,
been one of specialization — categorizing and separating domains and building
understanding within those ever smaller systems. The
approach has produced remarkable achievement, yet in a century in which our
sensing capabilities are revealing cross-scale behavior, data analysis and
computational tools are enabling cross-system research, and the demands on
our science are growing exponentially (e.g., dependence on space, risk of
space weather, dissolving of the boundary between Heliophysics and humanity),
our community faces the need to shift the paradigm [Kuhn, 1962] — the advent
of Complexity Heliophysics. Complexity is a term often confused to mean
complicated, but principally complexity is the study of phenomena which
emerge from a collection of interacting objects. In the context of
Heliophysics it is the study of the Sun, interplanetary environment,
magnetosphere, upper and terrestrial atmospheres, and planetary surface.
Heliophysics from the complexity perspective will be from systems-level
analyses and their methodologies. While the toolkit for an existing heliophysicist contains: correlational analysis, scale-dependent
understanding, and case studies; Complexity Heliophysics will embrace the
toolkit of the complexity scientist: information theory, network analysis,
multiscale/multifractal descriptions, system science, computation,
intelligent algorithms. This poster will shape a vision for a new science of
Complexity Heliophysics, presenting existing research that are selected
glimpses into that future. While a companion poster will focus on the
observations needed for understanding systems and across scales (c.f., Eric
Donovan), our focus will be on the organization, analysis, and communication
of data, those elements of improved information representation that underlies
complexity science.
The complexity paradigm will reach all aspects of Heliophysics research, how
we understand our data, science questions we ask, even missions we target.
The goal is to engender a Kuhnian atmosphere of paradigmatic shift in
Heliophysics science (and, correspondingly, culture).
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Mukherjee S.
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Impact of Solar Variability on
Planetary Systems [#2014]
Impact
of solar flare, coronal mass ejection during solar maximum, and galactic
cosmic ray influence during solar minimum is a matter of concern in the Earth
and its planets. Earth’s polar region shows variations of heliophysical
influence in comparison with the equatorial region. Martian and Lunar
equatorial and polar regions have been chosen for this study as selective
landform formation due to the solar radiation effect. Planet Earth has shown
variations of solar influence in space and time. The attempt was based on the
changes in the concentration of atmospheric gases like Sulpher
Dioxide, Nitrogen Dioxide, Aerosol and Cloud cover on the Earth during
changes within the Sun. A similar direct correlation of cosmic ray intensity,
heliophysical and atmospheric variation during the
solar eclipse has been recorded. Planet-directed coronal mass ejection and
solar flare prominence may influence the fluctuations in the upper part of
the surface. Effect of the Sun on Ice-water system was found out to be more
prominent in different planets under investigation. The magnetic field in
between Sun-Mars-Saturn and Sun-Moon is different. Using Mars Orbiter Probe (Mangalyan) and Indian Lunar Probe (Chandrayan-1)
different morphological features on the martian and lunar surface were
inferred. The sinuous ridges, or eskers, seen in the northern side of the
peak ring basin on Mars are an outcome of fluvial-glacial activity in the
area. These are branched and often interrupted in places. They seem to have
formed due to the melting of basal ice as a result of
heating and as the ice melted over time, sub-glacial tunnels filled with
deposits remained forming long winding ridges. The channels in show Mars some
ring and crater rim with dendritic patterns not typical of the lava flow. This
confirms fluvial activity in the later stages of the modification process.
While the findings on Moon are more exciting it shows that the tectonic
activities in the South Pole are more than the North Pole and
the Equator.
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Narock A. A. Thompson B. J. McLarney E. L. Kirk M. S. Bard C. M. Dorelli J. C. Mcgranaghan R. M.
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Ethical AI and Responsible Data Science for Heliophysics [#2157]
Ethical
AI is more than ensuring that decisions made by machines are in the best
interest of humanity. It includes interpretable results, no matter how
sophisticated or complicated the method. It includes ensuring scientific
robustness and integrity for both the science topic and the team members. It
includes an environment where diverse voices are heard and respected. Most of
the elements of Ethical AI consist of best practices for Heliophysics in
general. However, it is important to explore these principles under the lens
of data science, machine learning, and artificial intelligence. As our field
continues to embrace new and increasingly abstract methods, Ethical and
Responsible AI ensures that the practice of and results derived from machine
learning remain rooted to our core values of scientific integrity and
equitable team functionality. The upcoming NASA publication “NASA Framework
for the Ethical Use of Artificial Intelligence (AI)” presents guidelines for
six principles of Ethical AI: (1) Fair; (2) Explainable and
Transparent; (3) Accountable; (4) Secure and Safe; (5) Human-Centric and
Societally Beneficial; (6) Scientifically and Technically Robust. The Center
for HelioAnalytics at NASA GSFC is adopting these
guidelines and determining how they map into the field of HelioAnalytics.
This presentation will describe elements of Ethical and Responsible AI, and
report on efforts to produce community resources for responsible and
explainable data science.
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Olson J. Lichko E. Endrizzi D. Juno J. Dorfman S. Young R.
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Enhancing Collaboration Between Laboratory
Plasma Experiments and the Heliophysics Community [#2164]
With a
demonstrated ability to investigate both the 3D and multi-scale nature of
heliospheric phenomena, laboratory plasma experiments are an important
complement to the work of current and future spacecraft missions (MMS, HelioSwarm, etc.) and computational studies. Basic plasma
user facilities (WiPPL, LAPD, MPRL, etc.) provide a
platform for the heliophysics community to develop relevant experiments for
this purpose. However, there exists a significant knowledge barrier for
potential researchers without a background in experimental plasma physics to
effectively use these tools. This poster will focus on a call for increased
funding for human and physical infrastructure at laboratory plasma facilities
to more equitably serve users from a diverse range
of institutions and continually expand the explorable parameter space of
plasma systems. In addition, there should be continued education of
early-career scientists to create a workforce better prepared to integrate
laboratory experiments in their own work. This poster will illustrate the
importance and potential of laboratory experiments to address these open
questions by including recent results from the Wisconsin Plasma Physics
Laboratory relevant to magnetospheric magnetic reconnection. This work shows
that in a system a highly driven inflow, magnetic pileup is shown to enhance
the upstream Alfven speed, lowering the normalized reconnection rate to
values expected from theory. Given the small relative system size, the
reconnection rate approaches values up 0.8, consistent with a transition to
electron-only reconnection observed in the magnetopause.
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Panasenco O. Velli M. Tenerani A. Runov A. Artemyev A. Thripati S. Nishimura T. Downs C. Lynch B. J. Lin Y. Wang X. Innocenti M. E. Titov V. Egedal J. Abbett B. HERMES Team
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The HERMES NASA DRIVE Science Center as a Unifying Laboratory for
Fundamental Physics of the Sun, Heliosphere, Magnetosphere, and Applications
for Astrophysics [#2147]
Solar
magnetic activity provides the dynamic, pulsating heart of the Heliosphere.
The transformations of energy that accompany solar magnetic activity remain a
mysterious, complex phenomenon, with ramifications that extend beyond space
physics into astrophysics as a whole. Routine human
presence in near-Earth space and space travel depends on specification, with
predictive capability, of galactic and solar energetic particle fluxes and
other space weather phenomena. Understanding the dynamical chain — magnetic
activity to wind to interaction with planets — is fundamental to assess
habitability and the capacity for life elsewhere. The HERMES (HEliospheRic Magnetic Energy Storage and conversion)
DRIVE Center provides a unifying framework characterizing the basic
mechanisms of energy storage and release in the natural plasmas of the
heliosphere, incorporating the lessons learned within individual specialized
subfields and providing a unifying theme to further our understanding of
nonlinear plasma dynamics underlying the energy transformations that define
the Heliosphere. The full benefits of synergies between theory, modeling,
data analysis and machine learning requires the coherent structure the HERMES
Science Center, where experts from the different specialized areas, methods and environments, can work collaboratively to
broaden the useful datasets and investigation methods, move beyond simplistic
analogy in modeling different environments, find synergies and learn new
techniques to analyze the vast amounts of data collected from earth and from
space. Integration of theoretical modeling, multi-scale numerical
simulations, comprehensive remote sensing and
in-situ observations to solve the physics of Space Weather; provide state of
the art STEM education to diverse student populations; bring machine learning
and AI into data analysis and numerical modeling of the solar system space
environment and fundamental for astrophysics. This work was supported by the
NASA HERMES DRIVE Science Center grant No. 80NSSC20K0604.
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Paxton L. J.
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Reframing Heliophysics as Discovery and
Exploration Science [#2113]
The
aftermath of the Covid-19 pandemic is likely to bring all NASA budgets (and
other Federally funded activities) under scrutiny. The multi-trillion dollar relief programs will be paid from the
budget over the course of the next decades. Heliophysics can once again
inspire wonder, participation and innovation.
Heliophysics also enables the outward journey. The use of outer space as a
global resource for supporting our society is well-recognized. There are two
new relevance areas for Heliophysics:
space traffic management and cis-lunar operations. Space traffic
management will become more of an issue as tens of thousands of satellites
are placed in LEO where atmospheric drag can have a small but important
impact on the validity of orbit predictions. Note that an orbit prediction
must be accurate to within 1m or 0.0001 sec in order to
be useful for taking action and it must be available with sufficient warning
to be able to take action. As part of human and robotic exploration and, in particular, missions to the Moon and cis-lunar space,
predicting the magnitude and timing of energetic particle events will become
necessary.
In summary, the Vision for the Heliophysics Roadmap, can be tied to the
broadest and most compelling themes of NASA’s exploration activities and can
inspire the next generations of scientists and engineers. We can still do our
science while providing relevance to societal needs and creating a inclusive, enabling
environment with missions ranging from cubesats to
large observatory class missions.
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Rymer A. M. Korth H. Westlake J. H. Retherford K. D.
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Cross-Divisional Opportunities to Maximize the Science Return from
Solar System Missions [#2155]
Missions
to the outer solar system provide numerous opportunities for
cross-disciplinary science and collaboration. To be successful, missions must
clearly address Divisional goals as defined in the Decadal Surveys conducted
by the National Academies of Sciences. It is advantageous to be focused,
following clear hypothesis driven science questions. This approach has
produced excellent mission concepts with well-defined scientific goals and
priorities. In order to further maximize the science
return from future missions (e.g., Europa Clipper – launch 2024; a
long-anticipated voyage to Uranus and Neptune and an Interstellar Probe), it
is advantageous to identify and plan for science opportunities that can be
achieved by the spacecraft that would address additional Divisional and
cross-Divisional goals. Such joint efforts could be vastly improved upon,
and, in order to maximize opportunities and
cost-sharing, woven into projects from inception. As an example of one
strategy to foster collaboration and cost-sharing, the ‘directed good
fortune’ represented by NASA Missions of Opportunity, MoOs,
is an excellent model that could be more broadly applied. In this
presentation, we provide examples of achievements through both fortuitous and
directed collaboration and suggest strategies to identify and enable
cross-division collaboration and cost-sharing to improve cost and effort
effective science return over the upcoming decades.
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Schonfeld S. J. Higginson A. K. Alterman B. L. Kirk M. S. F.
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HelioWeb: A Resource for 21st
Century Science [#2078]
To meet
the ever-accelerating pace of heliophysics discovery driven by exciting new
missions, data products, analysis tools, and open-access science, the
community must leverage the promise of a digital future. We propose the
creation of a “HelioWeb” that connects researchers
and resources, a single portal through which all heliophysics knowledge is
cataloged, interlinked, and discoverable. HelioWeb
will: (1)
enable scientific discovery through improved data, tool, and knowledge
access; (2) strengthen the community by facilitating the development of
collaborations, the coordination of research efforts, and the recruitment and
training of new scientist; and (3) provide a unified hub of information and
resources for public education and outreach. HelioWeb
must also promote the decentralization and democratization of heliophysics
research and expand scientific networks to include and embrace traditionally
underserved and undervalued communities. We explore existing and developing
resources and technologies and envision how to combine and expand them to
realize a more inviting, interconnected, equitable, and efficient online
heliophysics community in 2050 and beyond.
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Snyder R. M. Halford A. J. Naasz B. J. Brown T. L. Easley J. W. Lupisella M. L. Roberts B. J.
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Enabling Long-Term Solar Cycle Science Through In-Space Servicing [#2105]
Solar
dynamics occur on a large timescale that is best observed by very long
lifespan missions. Cooperative servicing can extend satellite operations over
decades to observe multiple solar cycles in their entirety. Consistent in
situ and remote observations would help explain such phenomenon as the
drastic changes in the radiation belts between two solar cycles, Li et al
2017, where data from multiple satellites show that there was a depletion of
>2MeV electrons during the second solar cycle. If these
type of events were well understood, they could be used to make more
informed estimates of energy deposition at aviation altitudes, as well as the
source population and acceleration mechanisms that dominate the magnetosphere
between solar cycles. To address science questions on decade timescales with
consistent datasets, we need to consider orbiting platforms that are continuously
renewed. Industry, and government agencies are making the investments to
establish a robotic servicing infrastructure and refueling depot services
that will expand the frontier for long-term scientific measurements and
unprecedented data continuity. Robotic servicers are capable of autonomously
capturing satellites in order to refuel and extend
the lifespan of that measurement, as well as to reconfigure and repair
scientific observatories, so that new instruments can be installed adjacent
to heritage instruments to calibration between them. By 2050 we hope that it
is standard practice to maintain these observational platforms, but the work
to begin designing them begins now. NASA’s Exploration & In-space
Services (NExIS) project office at Goddard Space
Flight Center (GSFC) will present the cooperative servicing spectrum for the
heliophysics community to consider as they begin collaborating on the decadal
studies. Incorporating these design features will enable access to the
servicing infrastructure. The Earth science community saw a transformation in
their understanding of the terrestrial weather system with the expansion of long term datasets in the 20th century, which they used to
improve their forecast models. By 2050, we hope that the same will be true
for the heliophysics and space weather communities by providing consistent
datasets over long timescales. By incorporating cooperative servicing
features into our missions, we see the potential for the heliophysics
community to take this giant leap forward in our understanding by realizing
very long timescale missions.
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Summerlin E. J. Pulkkinen A. A. Vourlidas A. Korendyke C. N.
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Co-Axial Tomography of the Solar Corona and Near
Sun Environment (CATSCANS) [#2073]
The
STEREO mission gave us a tantalizing glimpse of the capabilities of
multi-spacecraft imaging to resolve coronal structures and extract
information vital to modeling and forecasting solar events. However, it also
demonstrated the limitations posed by a limited number of spacecraft.
While significant progress has been made over the past two decades in
detecting, analyzing, and understanding CMEs and associated energetic charged
particles, another breakthrough is needed in our observing capability of
solar transients and their heliospheric consequences to facilitate the next
generation science needed to uncover the complex three-dimensional (3D)
internal structure of CMEs. Advances in smallsat
communications and miniaturization of coronagraphs make feasible
multi-spacecraft missions to image solar transients from multiple viewpoints
at reasonable cost. As the number of spacecraft
increases from a half-dozen in 2030 to dozens in 2050, the 3D reconstruction
of these structures will improve commensurately allowing a full
self-consistent modeling of both the magnetic and plasma 3D structure of a
CME and thus leading to robust quantification of the space weather effects of
CMEs, for the first time. These advances can be used predictively to
safeguard space assets and the journey to Mars.
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Turner D. L. Cohen I. J. Gkioulidou M. Clark G. Brandt P. Rymer A. Vievering J. Chartier A. Merkin V. Provornikova E. Ukhorskiy A. Westlake J. Nikoukar R. Paxton L. Millan R. Slavin J. Bagenal F. Bornik J. Jaynes A. Wilson L. B. III DiBraccio G. A. Gershman D. Kepko E. L. Goldstein J. McGranaghan R. Claudepierre S. G. Gabrielse C.
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Re-Envisioning Heliophysics for 2050:
A Compelling Discipline with a Unified Identity, New Brand, and
Long-Term Vision [#2087]
As a
unified community, we should strive to develop a coherent and effective brand
for Heliophysics, a brand that we can use to better express the relevance of
our science to other grand scientific endeavors and more generally to society as a whole. The other divisions in NASA SMD have
clear, overarching brands: Earth
Sciences ultimately studies the nature and future of our home world and our
anthropogenic impacts upon it; Planetary Sciences is leading the charge to
find life on other worlds and understand how planets, including our own,
formed; Astrophysics is tackling the origins of the Universe itself and where
else life may exist. Heliophysics must rival these empowering brands to
justify our existence and make a strong case for why we deserve an SMD budget
on par with Earth Sciences, Planetary Sciences, and Astrophysics. Is
Heliophysics not the bridge that ties the other three divisions together?
Heliophysics explores and defines the space between Earth, the planets, and
the stars, and considering those intersections between Helio
and the other three NASA SMD divisions, Heliophysics is a truly
cross-divisional discipline. Heliophysics quite literally studies the physics
of our Sun as a star and our Heliosphere as an astrosphere, the space
environment that spans between Earth and the other planets and beyond into
interstellar space, and how stellar winds and energy input shape planetary
atmospheres and near-space environments and drive the space weather that
adversely impacts our technology and health. With a combination of remote
sensing and in situ observations, Heliophysicists
directly study the only planetary space environments and stellar and
interstellar systems that are currently within reach to do so, and also the only ones that we know of that do indeed
harbor life. Furthermore, it is into that space environment, those turbulent
and volatile leagues of particles and fields that fill the void between Earth
and the Moon and Mars and beyond, that humanity must venture as we pursue our
dreams of traveling to and establishing humanity on worlds beyond our home
planet. The future of our species depends on us at some point traversing that
space environment, the science of which is purely the territory of
Heliophysics. Thus, to address the concerns outlined above, we argue that we
as a unified Heliophysics community consider a new brand to advocate our
science, “Heliophysics: Understanding the space we live in and our home in
the galaxy.”
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