ST1.4 | Outstanding Questions in Heliophysics
EDI
Outstanding Questions in Heliophysics
Co-organized by NP8
Convener: Rumi Nakamura | Co-conveners: Jonathan Rae, Chris Arridge, Lina HadidECSECS, Louise Harra
Orals
| Thu, 27 Apr, 16:15–17:50 (CEST)
 
Room M2, Fri, 28 Apr, 10:45–12:30 (CEST)
 
Room 1.61/62
Posters on site
| Attendance Thu, 27 Apr, 14:00–15:45 (CEST)
 
Hall X4
Posters virtual
| Attendance Thu, 27 Apr, 14:00–15:45 (CEST)
 
vHall ST/PS
Orals |
Thu, 16:15
Thu, 14:00
Thu, 14:00
Activities including the recent ESA Voyage 2050 exercise and the ongoing Heliophysics Decadal Survey in the US have triggered various new ideas on fundamental science themes in the area of solar, solar wind, magnetosphere, ionosphere-thermosphere physics at Earth and different planets, plasma physics around the moon and small body, as well as in the heliospheric boundary region. While the idea of implementation scheme (mission) may differ, there are commonality in the underlying physical processes of interest. Discussing the outstanding problems throughout the heliosphere by bringing the different discipline should bring us new perspective of the broad science area. In this session we invite papers which highlight the outstanding science questions in the different area of space plasma physics throughout the solar system and beyond. Ideas on new observations in space and from ground, new modeling, suggestions on new data analysis schemes are also welcome. We welcome active participation of Early Career Scientists and experts from the broad international heliophysics community

Orals: Thu, 27 Apr | Room M2

Chairpersons: Rumi Nakamura, Jonathan Rae, Louise Harra
16:15–16:20
Sun and Heliosphere and beyond
16:20–16:30
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EGU23-6626
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ST1.4
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ECS
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solicited
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On-site presentation
Samuel Badman, Yeimy Rivera, Stuart Bale, and Michael Stevens

 The global structure of the Sun’s extended corona is governed by the physical processes which represent some of the biggest outstanding questions in heliophysics. These include the nature of coronal heating and solar wind acceleration. NASA’s Parker Solar Probe (PSP) offers unique new opportunities to probe this structure directly through its unprecedented orbit which takes it closer to the Sun than any prior spacecraft. As of Spring 2023, PSP has achieved perihelia of 13.3 Rs, but will continue to dive deeper to an eventual closest approach of 9.8Rs at the end of 2024. Already PSP is starting to offer tantalizing glimpses into the sub-alfvenic corona. The most recent orbits exhibit hints of an imminent global plasma regime change on multiple fronts: As well as unambiguous crossings of the Alfven critical surface, PSP sees significant solar wind deceleration, possible global magnetic field reorganization, and proton core temperatures hot enough to be comparable to isothermal solar wind models. In this talk, we will discuss how these exciting initial measurements may become decisive constraints in the latter orbits of the PSP mission. We trace the implications of making such direct measurements of the corona-solar wind transition to the science questions of coronal heating and solar wind acceleration.

How to cite: Badman, S., Rivera, Y., Bale, S., and Stevens, M.: Global coronal structure and possible new insights in the upcoming perihelia of Parker Solar Probe, EGU General Assembly 2023, Vienna, Austria, 23–28 Apr 2023, EGU23-6626, https://doi.org/10.5194/egusphere-egu23-6626, 2023.

16:30–16:35
16:35–16:45
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EGU23-17230
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ST1.4
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On-site presentation
Nour E. Raouafi and the The Firefly Constellation Team

Firefly is an innovative mission concept study for the Decadal Survey for Solar and Space Physics (Heliophysics) 2024-2033 to fill long-standing knowledge gaps in Heliophysics. A constellation of spacecraft will provide both remote sensing and in situ observations of the Sun and heliosphere from a whole 4π-steradian field of view. The concept implements a holistic observational philosophy that extends from the Sun’s interior, to the photosphere, through the corona, and into the solar wind simultaneously with multiple spacecraft at multiple vantage points optimized for continual global coverage over much of a solar cycle. The mission constellation includes two spacecraft in the ecliptic and two flying as high as ~70º solar latitude. The ecliptic spacecraft will orbit the Sun at fixed angular distances of ±120º from the Earth. Firefly will provide new insights into the fundamental processes that shape the whole heliosphere. The overarching goals of the Firefly concept are to understand the global structure and dynamics of the Sun’s interior, the generation of solar magnetic fields, the origin of the solar cycle, the causes of solar activity, and the structure and dynamics of the corona as it creates the heliosphere. We will provide an overview of the Firefly mission science and architecture and how it will revolutionize our understanding of long-standing heliospheric phenomena such as the solar dynamo, solar cycle, magnetic fields, solar activity, space weather, the solar wind, and energetic particles

How to cite: Raouafi, N. E. and the The Firefly Constellation Team: The Firefly Constellation: The Need for a Wholistic View of the Sun and its Environment, EGU General Assembly 2023, Vienna, Austria, 23–28 Apr 2023, EGU23-17230, https://doi.org/10.5194/egusphere-egu23-17230, 2023.

16:45–16:55
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EGU23-9872
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ST1.4
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On-site presentation
Pontus Brandt, Alan Stern, Linda Spilker, Heather Elliott, Matt Hill, Peter Kollmann, Ralph McNutt, Parisa Mostafavi, Dave McComas, Randy Gladstone, Mihaly Horanyi, Andrew Poppe, Elena Provornikova, Jeff Linsky, Seth Redfield, Tod Lauer, Kelsi Singer, John Spencer, Anne Verbiscer, and Merav Opher

Our solar system has evolved through accretion of dust and gas as the Sun and its protective magnetic bubble – “the heliosphere” - have plowed through interstellar space on its journey through the galaxy. Over the course of its evolution, the solar system has encountered dramatically different interstellar properties resulting in a severely compressed heliosphere with periods of full exposures of interstellar gas, plasma, dust and galactic cosmic rays (GCRs) that all have helped shaped the system we live in today. Our current knowledge lacks the direct measurements necessary to understand how our star upholds its vast heliosphere and its potentially game-changing role in the evolution of our galactic home.

Voyager 1 and 2 are now in the Very Local Interstellar Medium (VLISM), where they are expected to operate until the mid-2030’s having uncovered many unexpected discoveries and mysteries. After its paradigm-shifting discoveries at Pluto and Arrokoth, New Horizons is currently the only spacecraft in the outer heliosphere and is following the same heliospheric longitude as Voyager 2, but in the ecliptic plane – a trajectory that intersects the IBEX ribbon. It is projected to operate across the heliospheric termination shock and possible the heliopause with new measurements that will shed light on many of the mysteries of our heliosphere. Now passing 55 au, New Horizons is uniquely positioned to investigate the evolution of the solar wind, energetic particles, GCRs, and, in particular interstellar Pick-Up Ions (PUIs) that Voyager was not equipped to measure, to help constrain the structure and dynamics of the heliosphere. Observations of GCRs offers an opportunity to understand how these scatter strongly in the wavy structure of the “ballerina skirt” of the solar magnetic field leading to the strong modulation as part of the overall heliospheric shielding.

As New Horizons continues to travel outward, dust measurements may reveal an interstellar component that will provide the strongest constraint to date on how interstellar dust grains interact with the heliosphere. Now beyond the infrared and UV haze of the circumsolar dust and hydrogen gas, the Alice UV camera holds promise to search for signatures of the hydrogen wall and perhaps even signatures of our neighboring interstellar clouds.

New Horizons continues to break new ground in understanding the formation of our solar system by revealing the properties of multiple distant Kuiper Belt Objects and provide critical constraints on the structure of the Sun’s enormous dust disk. Because of its distant position, New Horizons is also providing the unprecedented estimates of the cosmic background.

In this presentation we provide an overview of New Horizons’ heliophysics observations in the context of the exploration by Voyager, IBEX, and IMAP. We conclude by providing a status of the future Interstellar Probe mission concept that is now under consideration in the Solar and Space Physics Decadal Survey.

How to cite: Brandt, P., Stern, A., Spilker, L., Elliott, H., Hill, M., Kollmann, P., McNutt, R., Mostafavi, P., McComas, D., Gladstone, R., Horanyi, M., Poppe, A., Provornikova, E., Linsky, J., Redfield, S., Lauer, T., Singer, K., Spencer, J., Verbiscer, A., and Opher, M.: Our Heliosphere in the Very Local Interstellar Medium: Exploration by New Horizons, Voyager, IBEX, IMAP and a Future Interstellar Probe, EGU General Assembly 2023, Vienna, Austria, 23–28 Apr 2023, EGU23-9872, https://doi.org/10.5194/egusphere-egu23-9872, 2023.

16:55–17:05
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EGU23-4065
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ST1.4
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On-site presentation
Robert F. Wimmer-Schweingruber, Nicolas André, Stas Barabash, Pontus C. Brandt, Timothy S. Horbury, Luciano Iess, Benoit Lavraud, Ralph L. McNutt, Jr., Elena A. Provornikova, Eric Quémerais, Robert Wicks, Martin Wieser, and Peter Wurz

Stella is a proposed European contribution to NASA’s Interstellar Probe (ISP), a large-strategic mission candidate. ESA’s call for M-class mission proposals was the best and only currently available option for the European science community to contribute to the astronomically constrained ISP launch window in 2036 – 2037. Traveling with a speed of ~ 7.0 au/year ISP would reach 350 au during its nominal 50-year life-time. The proposed Stella contribution to ISP includes two core and two optional elements for the full complement:

• Core: Provision of European scientific instruments;

• Core: Provision of the European ISP communication system including the spacecraft’s 5-m high gain antenna;

• Full complement: ESA deep space communication facility: an extension of ESA’s DSA with a new antenna array;

• Full complement: Contribution to ISP operations to increase drastically the ISP and European payloads science return.

How to cite: Wimmer-Schweingruber, R. F., André, N., Barabash, S., Brandt, P. C., Horbury, T. S., Iess, L., Lavraud, B., McNutt, Jr., R. L., Provornikova, E. A., Quémerais, E., Wicks, R., Wieser, M., and Wurz, P.: STELLA—Potential European  contributions to a NASA-led interstellar probe, EGU General Assembly 2023, Vienna, Austria, 23–28 Apr 2023, EGU23-4065, https://doi.org/10.5194/egusphere-egu23-4065, 2023.

Plasma neutral interaction
17:05–17:15
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EGU23-5939
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ST1.4
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solicited
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On-site presentation
Theodoros Sarris and the co-authors of the white paper for the decadal survey for solar and space physics 2024-2033

The lower thermosphere-ionosphere (LTI) is a key transition region between the Earth’s neutral atmosphere and plasma-dominated space. Interactions between ions and neutrals maximize within the LTI and in particular at altitudes from 100 to 200 km, which is the least visited region of the near-Earth environment due to enhanced atmospheric drag. The lack of in situ co-temporal and co-spatial measurements of all relevant parameters and their elusiveness to most remote-sensing methods means that the complex interactions between neutral and charged constituents in the LTI remain poorly characterized to this date. This lack of measurements, together with the ambiguity in the quantification of key processes in the 100 to 200 km altitude range, affect current modeling efforts to expand atmospheric models upward to include the LTI and limit current space weather prediction capabilities. In this talk, fundamental science themes in ionosphere-thermosphere physics and related societal and operational needs are outlined; past proposed implementation schemes to sample this transition region are reviewed; and recent efforts by ESA and NASA to highlight outstanding science questions in the LTI and the need for in situ measurements to address them are presented.

How to cite: Sarris, T. and the co-authors of the white paper for the decadal survey for solar and space physics 2024-2033: Plasma-Neutral Interactions in the Lower Thermosphere-Ionosphere: The need for in situ measurements to address outstanding questions, EGU General Assembly 2023, Vienna, Austria, 23–28 Apr 2023, EGU23-5939, https://doi.org/10.5194/egusphere-egu23-5939, 2023.

17:15–17:20
17:20–17:30
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EGU23-6791
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ST1.4
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On-site presentation
Yoshifumi Futaana and the ESA Topical Team : Physics Of Plasma-Surface-Exosphere-Dust Coupling At The Lunar Surface For Future Exploration Programmes

Exploration of the Moon provides opportunities to investigate the deep space environment upstream of the geospace and the terrestrial magnetosphere and associated space weather phenomena. Moreover, the Moon interaction with the solar wind adds novel, interdisciplinary aspects to fundamental space research: a complex coupling between the solar wind/magnetospheric plasma – energetic particles – exosphere – dust – solid-surface – mini-magnetosphere. As the Moon is the next step in space exploration, characterizing the environment provides vital support to this endeavor. We note that investigations in this area of science are invaluable in providing a characterization of the environment for the needs of human exploration. On the other hand,  the lunar environment is fragile against human activities. For example, the total mass of the lunar atmosphere is of the order of 10 tons. Therefore, the environment will change drastically once human activity starts on the lunar surface. It is significantly essential to characterize the environment before the fragile lunar atmosphere is “contaminated” by human activities at the surface.
With these aspects as a background, we formed an ESA topical team to formulate scientific questions in space plasma physics that can be uniquely investigated on or near the lunar surface. We also derived the required measurements, which can be addressed by lunar missions in the short and long term, including the EL3 (European Logistic Lunar Lander) mission. This presentation introduces the background scientific context and describes the derived scientific concepts. 

How to cite: Futaana, Y. and the ESA Topical Team : Physics Of Plasma-Surface-Exosphere-Dust Coupling At The Lunar Surface For Future Exploration Programmes: Physics of plasma–surface–exosphere–dust coupling at the lunar surface for future exploration programmes, EGU General Assembly 2023, Vienna, Austria, 23–28 Apr 2023, EGU23-6791, https://doi.org/10.5194/egusphere-egu23-6791, 2023.

17:30–17:40
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EGU23-3517
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ST1.4
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ECS
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On-site presentation
Charlotte Goetz and the Cometary Plasma Science White Paper Team

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. We will review the present-day knowledge of cometary plasmas, discuss the many questions that remain unanswered, and outline a multi-spacecraft European Space Agency 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.

How to cite: Goetz, C. and the Cometary Plasma Science White Paper Team: Cometary Plasma Science - Open questions and implications for heliophysics, EGU General Assembly 2023, Vienna, Austria, 23–28 Apr 2023, EGU23-3517, https://doi.org/10.5194/egusphere-egu23-3517, 2023.

17:40–17:50
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EGU23-5715
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ST1.4
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On-site presentation
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Masatoshi Yamauchi, Johan De Keyser, George Parks, Shin-ichiro Oyama, Peter Wurz, Takumi Abe, Arnaud Beth, Malcolm Dunlop, Pierre Henri, Harald Kucharek, Octav Marghitu, Georgios Nicolaou, Manabu Shimoyama, Joachim Saur, Satoshi Taguchi, Takuo Tsuda, and Bruce Tsurutani

The majority of the atmospheres of solar system bodies are composed of neutral gas, and hence their upper atmosphere are always partially ionized by the solar UV and collisions, allowing a complex nonlinear interaction with interplanetary plasma.  Thus, ion-neutral and electron-neutral interaction plays a key role in this transition regions (ionosphere for planets and moons). However, our current understanding of plasma-neutral gas interactions is very limited due to lack of observations with proper instrumentation and to the difficulty in making laboratory experiments (almost impossible to reproduce the ionosphere with low energy plasma).  Particularly the effect of small amount of neutral species in space above the exobase and the effects of electric charges on neutrals have been underestimated.  

To advance our knowledge of these basic but still poorly understood interactions between plasma and neutral gas at key regions of energy, momentum, and mass exchange between the space and the atmosphere, we evaluate what kind of measurement package is needed for different solar system objects in a cost-effective manner.  We particularly focus on understanding the re-distribution of externally provided energy to the composing species through this interaction.  

The presentation is based on a white paper submitted to ESA's Voyage 2050 (Experimental Astronomy, 2022), and related mission proposals to space agencies.  Here we skip the chemical aspect that is also mentioned in the white paper.

Reference: https://doi.org/10.1007/s10686-022-09846-9

How to cite: Yamauchi, M., De Keyser, J., Parks, G., Oyama, S., Wurz, P., Abe, T., Beth, A., Dunlop, M., Henri, P., Kucharek, H., Marghitu, O., Nicolaou, G., Shimoyama, M., Saur, J., Taguchi, S., Tsuda, T., and Tsurutani, B.: Plasma-neutral gas interactions in various space environments beyond simplified approximations, EGU General Assembly 2023, Vienna, Austria, 23–28 Apr 2023, EGU23-5715, https://doi.org/10.5194/egusphere-egu23-5715, 2023.

Orals: Fri, 28 Apr | Room 1.61/62

Chairpersons: Rumi Nakamura, Lina Hadid, Chris Arridge
Solar wind and magnetospheres
10:45–10:55
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EGU23-13772
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ST1.4
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On-site presentation
Robert Wicks and Daniel Verscharen

ESA F-Class missions offer a new opportunity to do space science with smaller, cheaper spacecraft. The mission format presents a tough challenge for plasma physics missions, can we make simple, small and cost-effective spacecraft for a topic that will make breakthrough discoveries? This presentation will discuss the past two proposals of the Debye mission, the lessons learned and the challenges ahead to make a similar mission feasible. Debye addresses a grand-challenge problem at the forefront of physics: to understand how energy is transported and transformed in plasmas. The smallest characteristic scales, at which electron dynamics determines the behaviour of energy, are the next frontier in space and astrophysical plasma research. Debye will be the first electron-astrophysics mission. Electron-kinetic processes operate at very small scales (< 10 km) but define the behaviour of the plasma at system-size scales. Debye will use the solar wind as a natural plasma laboratory to measure these electron-scale processes. Understanding the heating, acceleration, thermalisation, and heat flux of electrons is fundamental to our understanding of the dynamics and thermodynamics of plasmas throughout the Universe and thus to the entire field of astrophysics. Debye will answer the fundamental science question "How are electrons heated in astrophysical plasmas?" The mission will make the highest-resolution measurements of electrons ever made in space in terms of energy, angle, time, and space, coupled with two-point high-cadence field measurements to identify the plasma fluctuations responsible for electron energisation. This mission concept will provide ground-breaking and transformative physics results since the combination of rapid particle and field measurements over distances of less than 10 km is completely unprecedented. We believe Debye is a fast, feasible, and focussed mission, tailored to achieve these science objectives, but there are some technical challenges that are assessed to be problematic, how can we address data transmission, formation flying, the cost of multi-item payloads and multi-spacecraft missions?

How to cite: Wicks, R. and Verscharen, D.: Electron-astrophysics in the solar wind: plasma physics at F-Class, lessons learned and things to do., EGU General Assembly 2023, Vienna, Austria, 23–28 Apr 2023, EGU23-13772, https://doi.org/10.5194/egusphere-egu23-13772, 2023.

10:55–11:05
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EGU23-2179
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ST1.4
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solicited
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On-site presentation
Elena Kronberg

The heliosphere is a part of the Universe in which we can do in situ measurements of plasma dynamics under diverse conditions. The terrestrial magnetosphere is especially well accessible for studying universal plasma processes, in particular those associated with the conversion and flow of electromagnetic and plasma energy. To fully understand phenomena such as shocks, instabilities at plasma boundaries, and magnetic reconnection it is crucial to consider the coupling between physical processes at small and large scales. Planetary magnetospheric systems are not completely understood, because kinetic and global scales are rarely measured simultaneously. In most observations, the energy range and composition are not resolved for all important contributors.  The mentioned aspects are essential for an assessment of the magnetosphere-ionosphere-atmosphere-subsurface coupling and for the prediction of space weather. The influence of ionospheric charged particles on the magnetospheric dynamics will be used as an illustrative example. 

How to cite: Kronberg, E.: Open questions in heliophysics: terrestrial laboratory, EGU General Assembly 2023, Vienna, Austria, 23–28 Apr 2023, EGU23-2179, https://doi.org/10.5194/egusphere-egu23-2179, 2023.

11:05–11:10
11:10–11:20
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EGU23-13687
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ST1.4
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Virtual presentation
Beatriz Sanchez-Cano and the the M-MATISSE team

The “Mars Magnetosphere ATmosphere Ionosphere and Space-weather SciencE (M-MATISSE)” mission is an ESA Medium class (M7) candidate currently in Phase 0 study by ESA. M-MATISSE’s main scientific goal is to unravel the complex and dynamic couplings of the Martian magnetosphere, ionosphere and thermosphere (MIT coupling) with relation to the Solar Wind (i.e. space weather) and the lower atmosphere. It will provide the first global characterisation of the dynamics of the Martian system at all altitudes, to understand how the atmosphere dissipates the incoming energy from the solar wind, including radiation, as well as how different surface processes are affected by Space Weather activity.

M-MATISSE consists of two orbiters with focused, tailored, high-heritage payloads to observe the plasma environment from the surface to space through coordinated simultaneous observations. It will utilize a unique 3-vantage point observational perspective, with the combination of in-situ measurements by both orbiters and remote observations of the lower atmosphere and ionosphere by radio crosstalk between them.

M-MATISSE is the product of a large organized and experienced international consortium. It has the unique capability to track solar perturbations from the Solar Wind down to the surface, being the first mission fully dedicated to understand planetary space weather at Mars. It will revolutionize our understanding and ability to forecast potential global hazard situations at Mars, an essential precursor to any future robotic & human exploration.

How to cite: Sanchez-Cano, B. and the the M-MATISSE team: The M-MATISSE mission: Mars Magnetosphere ATmosphere Ionosphere and Space weather SciencEAn ESA Medium class (M7) candidate, EGU General Assembly 2023, Vienna, Austria, 23–28 Apr 2023, EGU23-13687, https://doi.org/10.5194/egusphere-egu23-13687, 2023.

11:20–11:30
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EGU23-1094
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ST1.4
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solicited
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On-site presentation
Minna Palmroth and the Team

Rapid plasma eruptions explosively release energy in the Earth’s magnetosphere, at the Sun, and solar system planets. At Earth, these eruptions, termed plasmoids, occur in the magnetospheric nightside, and are associated with the sudden brightening of the aurora. The chain of events leading to the plasmoid is one of the longest-standing unresolved questions in space physics. Two competing paradigms, based on magnetic reconnection or kinetic instabilities, are proposed to explain the course of events. We report results of a major technological achievement modelling the Earth’s magnetosphere at realistic scales, with sufficient spatiotemporal resolution, and resolving ion-kinetic physics, and thereby capturing physics essential to both paradigms. We show that both magnetic reconnection and kinetic instabilities are required to induce a global topological reconfiguration of the magnetotail, thereby combining the seemingly contradictory paradigms. Our results show that magnetic reconnection creates local plasmoids that are combined into a tail-wide structure by a current sheet disruption in the center tail. Large-scale current sheet flapping, caused by a drift kink instability and driven by reconnection-generated ions, leads to the current disruption. Our results help to understand plasma eruptions ubiquitous in space plasmas, guide spacecraft constellation mission design, and lead to improved understanding of space weather. We also contemplate the future direction of models within the solar system plasma physics and heliophysics discipline.

How to cite: Palmroth, M. and the Team: Magnetotail plasmoid eruption: Interplay of instabilities and reconnection, EGU General Assembly 2023, Vienna, Austria, 23–28 Apr 2023, EGU23-1094, https://doi.org/10.5194/egusphere-egu23-1094, 2023.

11:30–11:35
11:35–11:45
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EGU23-3258
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ST1.4
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ECS
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On-site presentation
Sarah Bentley, Jen Stout, Daniel Ratliff, Rhys Thomspon, and Clare Watt

Earth’s radiation belts are a hazardous environment containing trapped charged particles. Radial diffusion is one of the major processes driving radiation belt physics, accounting for energisation, transport and loss of electrons in the outer belt. The outer radiation belt is highly variable in energy and location, resulting in behaviour which is difficult to model accurately.

 

Ensemble modelling is needed to characterise this variability. Ensembles can be constructed by varying physical parameters (capturing the uncertainty in our knowledge across many scales) and considering the spread of the final model outputs. However, it is unclear what proportion of the subsequent variability comes from physics versus the numerical methods used. We investigate the effect of varying initial conditions for typical radial diffusion coefficients.

 

We present two methods of establishing the timescale over which initial conditions affect the subsequent radial diffusion; time to monotonicity (the time taken for the particle distribution to reach a state where radial diffusion effects become uninteresting) and dimensional analysis. Both are needed to capture the processes we are interested in as well as the inherent timescales from diffusion. Our measures are often domain dependent, indicating that the choice of where we perform our radial diffusion simulations is significant.

 

How to cite: Bentley, S., Stout, J., Ratliff, D., Thomspon, R., and Watt, C.: Radial Diffusion Benchmarking: Initial Conditions, EGU General Assembly 2023, Vienna, Austria, 23–28 Apr 2023, EGU23-3258, https://doi.org/10.5194/egusphere-egu23-3258, 2023.

Coordination
11:45–11:55
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EGU23-9239
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ST1.4
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On-site presentation
Emil Kepko and the COSPAR Task Group on Establishing an International Geospace Systems Program

Heliophysics is the study of the Sun and its effects throughout the solar system. It covers an incredible range of scales, from plasma physics at the electron scale to the boundary that separates our solar system from interstellar space. It also includes a diverse array of sub disciplines and expertise, with measurements spanning in situ particles and fields from the ionosphere out to the Sun’s corona, to remote sensing of the Sun, heliosphere, and near-Earth environment at multiple wavelengths and in energetic neutral atom observations. Many of the biggest unanswered science questions that remain across Heliophysics center around the interconnectivity of the different physical systems that comprise the Heliosphere, and the role of mesoscale dynamics in modulating, regulating, and controlling that interconnected behavior. These are complex, yet ultimately fundamental questions of how the Sun-Heliosphere and Geospace interact, and answers are needed to more accurately predict and model space weather impacts on and around Earth, the moon, and Mars. To answer these long-standing questions on the Sun-Heliosphere and Geospace as system-of-systems, we believe that Heliophysics requires a coordinated, deliberate, worldwide scientific effort. We suggest that the worldwide Heliophysics discipline should embark on a grand program to study these system-of-systems holistically, with coordinated, multipoint measurements, with particular emphasis on resolving mesoscale dynamics, and a whole-of-science approach that includes ground-based measurements and advanced numerical modeling. Without such a unified, next generation ISTP-type program, these questions will remain largely unanswered. In this paper we lay out the case for such an approach, and discuss how the ITM community is using the upcoming NASA GDC mission as a cornerstone to develop the ITM Great Observatory, a grass-roots, holistic approach modeled after ISTP to study the ITM system.

How to cite: Kepko, E. and the COSPAR Task Group on Establishing an International Geospace Systems Program: ISTPNext and the ITM Great Observatory: The need for international coordination in Heliophysics, EGU General Assembly 2023, Vienna, Austria, 23–28 Apr 2023, EGU23-9239, https://doi.org/10.5194/egusphere-egu23-9239, 2023.

11:55–12:05
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EGU23-12289
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ST1.4
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ECS
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On-site presentation
Sophie Musset, Lindsay Glesener, Ramana Sankar, Lucy Fortson, Paloma Jol, Kekoa Lasko, Yixian Zhang, Navdeep Panesar, Gregory Fleishman, Mariana Jeunon, Neal Hurlburt, and Yuping Zheng

Citizen science provides a way to analyze large and complex data sets, complementary to contemporary tools such as machine learning. Indeed, while trained algorithms excel in the task they are trained for, humans can spot outliers and make serendipitous discoveries. With recent and new instruments, we are able to observe the Sun and the heliosphere at high cadence and high resolution, providing large amounts of data, revealing complexity in the observed features, and leading to the discovery of new features on small scales. We will present how citizen science, while still under-utilized in solar and heliospheric physics, is particularly adapted to explore, and analyze solar data sets. The “Solar Jet Hunter”, a citizen science project launched one year ago to build a catalog of coronal jets, will be presented as an example, and other science cases for which citizen science is the most adequate tool will be highlighted. Finally, the opportunities raised by citizen science to create strong relationships between academia and society will be discussed.

How to cite: Musset, S., Glesener, L., Sankar, R., Fortson, L., Jol, P., Lasko, K., Zhang, Y., Panesar, N., Fleishman, G., Jeunon, M., Hurlburt, N., and Zheng, Y.: Citizen science and the exploration of solar data, EGU General Assembly 2023, Vienna, Austria, 23–28 Apr 2023, EGU23-12289, https://doi.org/10.5194/egusphere-egu23-12289, 2023.

12:05–12:15
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EGU23-11768
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ST1.4
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On-site presentation
Go Murakami and Johannes Benkhoff

In the 2020s we are entering a golden age of inner heliosphere science. International Mercury exploration mission BepiColombo was launched in 2018 and will arrive at Mercury in 2025. During the interplanetary cruise phase, BepiColombo will range from 1.2 AU to 0.3 AU, and will stay in the inner heliosphere for long time. BepiColombo started its science observations during the interplanetary cruise phase in 2020. The initial results showed its enough performance to observe solar wind electrons, IMF, and solar energetic particles (SEPs) even in the composite spacecraft configuration. Especially in 2021 two spacecraft of BepiColombo, Mercury Planetary Orbiter (MPO) and Mercury Magnetosphere Orbiter (Mio), successfully detected many SEP events. BepiColombo can contribute to leading and expanding the heliospheric system science. In addition to BepiColombo, NASA’s Parker Solar Probe and ESA’s Solar Orbiter are also exploring the inner heliosphere. Coordinated observations between these multi spacecraft have been planned and performed. In March 2021, we also coordinated a joint observation campaign of the solar corona and solar wind with BepiColombo, Akatsuki, and Hinode. These coordinated observations/analysis with multi spacecraft, ground-based observations, and numerical simulations can give us great opportunities to address outstanding questions in heliophysics. Here we Here we present the overview and updated status of BepiColombo and the coordinated science observations.

How to cite: Murakami, G. and Benkhoff, J.: Coordinated observations for inner heliospheric science: contribution by the BepiColombo mission, EGU General Assembly 2023, Vienna, Austria, 23–28 Apr 2023, EGU23-11768, https://doi.org/10.5194/egusphere-egu23-11768, 2023.

12:15–12:25
|
EGU23-9223
|
ST1.4
|
On-site presentation
Matthew Taylor, Piers Jiggins, Juha-Pekka Luntama, Astrid Orr, and Anja Strømme

Heliophysics, the science of understanding the Sun and its interaction with the Earth and the solar system, has a large and active international community, with significant expertise and heritage in the European Space Agency and Europe. Several ESA directorates have activities directly connected with this topic, including ongoing and/ or planned missions and instrumentation, comprising a ESA Heliophysics observatory or more musically, a Heliophysics Orchestra. More specifically in ESA: The Directorate of Science with mission such as Ulysses, SOHO, Cluster, Solar Orbiter, SMILE etc, as well as hosting the Heliophysics archive; The Directorate of Earth Observation with Swarm and other Earth Explorer missions, as well as the ongoing ESA-NASA Lower Thermosphere-Ionosphere Science Working Group (EN-LoTIS-WG); The Directorate of Operations with the Vigil mission, the Distributed Space Weather Sensor System (D3S) and the Space Weather Service Network; The Directorate of Human and Robotic Exploration with many ISS and LOP-Gateway payloads and the Directorate of Technology, Engineering Quality with expertise in developing instrumentation and models for measuring and simulating environments throughout the heliosphere.

An ESA Heliophysics Working group has been appointed by several ESA Directors, under the direction of the ESA Director General, to work on optimizing synergies across directorates, and to act as a focus for discussion, inside ESA, of the scientific interests of the Heliophysics community, including the European ground-based community and data archiving activities. 

How to cite: Taylor, M., Jiggins, P., Luntama, J.-P., Orr, A., and Strømme, A.: The ESA Heliophysics Working Group: building cross-discipline bridges to better serve the European Heliophysics  community, EGU General Assembly 2023, Vienna, Austria, 23–28 Apr 2023, EGU23-9223, https://doi.org/10.5194/egusphere-egu23-9223, 2023.

12:25–12:30

Posters on site: Thu, 27 Apr, 14:00–15:45 | Hall X4

Chairpersons: Lina Hadid, Louise Harra, Jonathan Rae
X4.201
|
EGU23-8879
|
ST1.4
Reka Winslow, Camilla Scolini, Noé Lugaz, Nathan Schwadron, and Antoinette Galvin

Coronal mass ejections (CMEs) contribute closed magnetic flux to the heliosphere while they are connected at both ends to the Sun and play a key role in adding magnetic flux to the heliosphere. Here, we discuss an outstanding question in heliophysics: how the type of magnetic reconnection that opens CME field lines in the inner heliosphere, i.e. interchange (IC) reconnection (below the Alfvén surface) and/or interplanetary (IP) reconnection (above the Alfvén surface), determines the length of time CMEs contribute to the heliospheric flux budget. Although IP reconnection does not alter the total amount of magnetic flux in the heliosphere, it matters in this context because it prevents the efficient opening of CME closed magnetic flux through IC reconnection, thereby prolonging the length of time that CMEs contribute closed magnetic flux to the heliosphere. We suggest that there is a varying timescale of contribution of individual CMEs to the heliospheric flux budget, with some CMEs contributing for considerably longer than others, depending on their interactions in IP space (i.e., depending on the fraction of the CME magnetic field lines opened up through IP reconnection vs. IC reconnection, or both). Such a distinction has not been taken into account in past studies that estimate the CME flux opening timescale. We outline key criteria to aid in distinguishing IC reconnection from IP reconnection based on in situ spacecraft data and highlight these through two example events. Studying the manner in which CMEs reconnect and open in the inner heliosphere has implications for a broad range of solar and heliospheric physics research areas and yields important insights not only into CMEs' role in the heliospheric flux budget but also the evolution of CME complexity, connectivity, and topology.

How to cite: Winslow, R., Scolini, C., Lugaz, N., Schwadron, N., and Galvin, A.: On the Contribution of Coronal Mass Ejections to the Heliospheric Magnetic Flux Budget on Different Time Scales, EGU General Assembly 2023, Vienna, Austria, 23–28 Apr 2023, EGU23-8879, https://doi.org/10.5194/egusphere-egu23-8879, 2023.

X4.202
|
EGU23-16967
|
ST1.4
Vladimir Florinski, Juan Alonso Guzman, Merav Opher, and Keyvan Ghanbari

The Voyager space probes provided us with a global perspective on galactic cosmic ray transport through the heliosphere at low to moderate heliographic latitudes, as well as their behavior at the boundary with the very local interstellar medium (VLISM). There remain, however, multiple interesting region the Voyagers have not visited, including high latitudes and the distant flanks of the heliopause where long-term trapping of charged particles is though to take place. We attempt to fill the gaps in our understanding of the distant heliosphere using computer simulations. The Space Plasma and Energetic Charged particle TRansport on Unstructured Meshes (SPECTRUM) code is a versatile software platform to perform tracing of particle trajectories using multiple physics models and internal or externally provided MHD background data. We apply the model to the problem of galactic cosmic ray transport in the outer heliosphere and the surrounding very local interstellar medium (VLISM) using the MHD background provided on a adaptive block mesh from the Space Weather Modeling Framework (SWMF). We compare the guiding center and nearly isotropic (Parker) physics models and elucidate the role of perpendicular diffusion in cosmic-ray penetration through the heliospheric boundary.

How to cite: Florinski, V., Alonso Guzman, J., Opher, M., and Ghanbari, K.: A new approach to modeling galactic cosmic rays in the heliosphere using arbitrary data driven MHD backgrounds, EGU General Assembly 2023, Vienna, Austria, 23–28 Apr 2023, EGU23-16967, https://doi.org/10.5194/egusphere-egu23-16967, 2023.

X4.203
|
EGU23-14278
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ST1.4
|
ECS
Rong Lin, Jiansen He, and Chuanpeng Hou

The PSP observation of a long-lived sub-Alfvénic solar wind, along with its magnetic-dominant character, marks a milestone that a human spacecraft has entered the solar corona for the first time (Kasper et al. 2021 PRL). In fact, sub-Alfvénic solar wind streams have also been observed multiple times near the earth by WIND spacecraft. What are the difference and possible connections between the sub-Alfvénic streams very close to the sun and the sub-Alfvénic streams 1 au from the sun? What process generates and sustains the near-earth sub-Alfvénic streams as they propagate outwards? Why the yearly occurrence frequency of them strongly correlates with solar activity? We study several sub-Alfvénic streams, which can be categorized into two groups: sub-Alfvénic background solar wind and sub-Alfvénic ICMEs. In-situ observations, remote observations, and connecting tools are used in our study. We find the sub-Alfvénic background streams are magnetic enhancements embedded in rarefactions. Their origin can be the boundary of the expanding coronal holes and shrinking active regions. A sub-Alfvénic ICME is generally a low-density part of the whole ICME, whose solar origin tends to be elusive in the coronagraph but still geomagnetically effective because of the ICME magnetic field.

How to cite: Lin, R., He, J., and Hou, C.: Sub-Alfvénic solar wind streams near the earth: characteristics and their origin, EGU General Assembly 2023, Vienna, Austria, 23–28 Apr 2023, EGU23-14278, https://doi.org/10.5194/egusphere-egu23-14278, 2023.

X4.204
|
EGU23-10279
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ST1.4
|
ECS
Parisa Mostafavi, Matthew Hill, Peter Kollmann, Pontus Brandt, Ralph McNutt, Alan Stern, Bishwas Shrestha, Fran Bagenal, Kelsi Singer, Anne Verbiscer, and John Spencer

Nonthermal energetic pickup ions (PUIs), created in the heliosphere by charge exchange between solar wind ions and interstellar neutral atoms, play an essential role in understanding solar wind evolution in the outer heliosphere and the structure and dynamics of the global heliosphere. New Horizons spacecraft, launched in 2006, is now located at about 55 au from the Sun, exploring the outer heliosphere, and is the only spacecraft equipped with proper instruments to measure nonthermal energetic pickup ions (PUIs) in the outer heliosphere for the first time. Its observations showed that energetic PUIs dominate the internal pressure of the outer heliosphere, with PUI pressures larger than the thermal solar wind and magnetic pressures outside ~ 20 au. At these distances, PUIs contribute substantially to heating and slowing down the solar wind. Moreover, New Horizons observations showed that PUIs mediate shock waves in the outer heliosphere. Here, we give an overview of the energetic particles in the outer heliosphere and their effect on shocks. We present the in situ observations of the hydrogen and Helium PUIs made by New Horizons' SWAP and PEPSSI instruments. Finally, we present some of the most important open questions related to the outer heliosphere that future studies and space missions should address.

How to cite: Mostafavi, P., Hill, M., Kollmann, P., Brandt, P., McNutt, R., Stern, A., Shrestha, B., Bagenal, F., Singer, K., Verbiscer, A., and Spencer, J.: Energetic Particles in the Outer Heliosphere, EGU General Assembly 2023, Vienna, Austria, 23–28 Apr 2023, EGU23-10279, https://doi.org/10.5194/egusphere-egu23-10279, 2023.

X4.205
|
EGU23-12578
|
ST1.4
Heavy Metal, an ESA M7 mission proposal
(withdrawn)
Jan-Erik Wahlund and the the Heavy Metal consortium
X4.206
|
EGU23-2060
|
ST1.4
Rongsheng Wang, Xinmin Li, Shimou Wang, Quanming Lu, San Lu, and Walter Gonzalez

Turbulent magnetic reconnection was observed in the magnetotail and the magnetopause. In turbulent magnetic reconnection, the diffusion region is filled with a number of filamentary currents primarily carried by the electrons and some flux ropes. These dynamic filamentary currents constitute a kind of three-dimensional network in the diffusion region and lead the reconnection into turbulence. The electrons are trapped and sufficiently accelerated inside such a complicated current network.

According to the previous observations, magnetic reconnection generally displays a quasi-steady state in the solar wind, where the energy is dissipated via slow-mode shocks. It is elusive why the reconnection in the solar wind is quasi-steady. Here we present a direct observation of bursty and turbulent magnetic reconnection in the solar wind, with its associated exhausts bounded by a pair of slow-mode shocks. We infer that the plasma is more efficiently heated in the magnetic reconnection diffusion region than across the shocks and that the flow enhancement is much higher in the exhausts than in the area around the diffusion region. We detected 75 other, similar diffusion-region events in solar wind data between October 2017 and May 2019, suggesting that bursty reconnection in the solar wind is more common than previously thought and actively contributes to solar wind acceleration and heating.

How to cite: Wang, R., Li, X., Wang, S., Lu, Q., Lu, S., and Gonzalez, W.: Turbulent magnetic reconnection in the solar wind, EGU General Assembly 2023, Vienna, Austria, 23–28 Apr 2023, EGU23-2060, https://doi.org/10.5194/egusphere-egu23-2060, 2023.

X4.207
|
EGU23-9043
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ST1.4
Maria Federica Marcucci, Alessandro Retinò, Malcolm Dunlop, Colin Forsyth, Yuri Khotyaintsev, Olivier Le Contel, Ian Mann, Rumi Nakamura, Minna Palmroth, Ferdinand Plaschke, Jan Soucek, Masatoshi Yamauchi, Andris Vaivads, and Francesco Valentini and the Plasma Observatory Team

The Earth's Magnetospheric System is the complex and highly dynamic environment in near-Earth space where plasma gets actively energized and transport of large amounts of energy occurs, due to the interaction of the solar wind with the Earth's magnetic field. Understanding plasma energization and energy transport is an open challenge of space plasma physics, with important implications for space weather science as well as for the understanding of distant astrophysical plasmas. Plasma energization and energy transport are related to fundamental processes such as shocks, magnetic reconnection, turbulence and waves, plasma jets and instabilities, which are at the core of the current space plasma physics research. ESA/Cluster and NASA/MMS four-point constellations, as well as the large-scale multipoint mission NASA/THEMIS, have greatly improved over the last two decades our understanding of plasma processes at individual scales compared to earlier single-point measurements. Despite the large amount of available observations, we still do not fully understand the physical mechanisms which give rise to plasma energization and energy transport. The reason is that the fundamental physical processes governing plasma energization and energy transport operate across multiple scales ranging from the large fluid to the smaller kinetic scales. Here we present the Plasma Observatory (PO) multiscale mission concept which is tailored to study plasma energization and energy transport within the Earth's Magnetospheric System. PO baseline is comprised of one mothercraft (MSC) and six identical smallsat daughtercraft (DSC) in an HEO 8 RE X 18 RE orbit, covering all the key regions of the Magnetospheric System where strong energization and transport occur: the foreshock, bow shock, magnetosheath, magnetopause, magnetotail current sheet, and the transition region. MSC payload provides a complete characterization of electromagnetic fields and plasma particles in a single point with time resolution sufficient to resolve kinetic physics at sub-ion scales. The DSCs have identical payload which is much simpler than on the MSC, yet giving a full characterization of the plasma at the ion and fluid scales. Going beyond Cluster, THEMIS and MMS, PO will permit us to resolve for the first time the coupling between ion and fluid scales as well as the non-planarity and non-stationarity of plasma structures at those scales.  PO is one of the five ESA M7 candidates to be launched around 2037 and is currently undergoing a competitive Phase 0 at ESA for further downselection to Phase A at the end of 2023.

How to cite: Marcucci, M. F., Retinò, A., Dunlop, M., Forsyth, C., Khotyaintsev, Y., Le Contel, O., Mann, I., Nakamura, R., Palmroth, M., Plaschke, F., Soucek, J., Yamauchi, M., Vaivads, A., and Valentini, F. and the Plasma Observatory Team: Plasma Observatory ESA M7 candidate mission: unveiling plasma energization and energy transport through multiscale observations, EGU General Assembly 2023, Vienna, Austria, 23–28 Apr 2023, EGU23-9043, https://doi.org/10.5194/egusphere-egu23-9043, 2023.

X4.208
|
EGU23-11849
|
ST1.4
Rumi Nakamura, Yoshizumi Miyoshi, and Evgeny Panov

A major part of the transport of the magnetic flux and energy in the midtail and the near-Earth tail region is accomplished by local fast plasma jets, called bursty bulk flows (BBF) or flow bursts.  The interaction between BBF and ambient field plays an important role in the complex chain of solar wind-magnetosphere-ionosphere coupling processes. Furthermore, near-Earth flow braking/bouncing processes and associated magnetic and pressure disturbances in the transition region of the magnetic field configuration from tail-like to dipolar field  lead to complex localized current sheet restructuring. Associated energetic particle injection further effects the inner magnetosphere bringing in the source population of the plasma waves that cause electron accelerations as well as seed populations of the radiation belts.

 

In this presentation we stress the importance of observations of BBF and dipolarization by covering extensive region, both near the equator and off-equator simultaneously, for understanding the energy transport processes by including both the field-aligned and perpendicular evolution of the flux tube.  By showing several examples of observations with fortuitous multi-spacecraft configuration, 3D nature of the interaction between BBF and ambient plasma will be discussed. 

 

 

How to cite: Nakamura, R., Miyoshi, Y., and Panov, E.: 3D evolution of localized plasma flow and its interaction with ambient field, EGU General Assembly 2023, Vienna, Austria, 23–28 Apr 2023, EGU23-11849, https://doi.org/10.5194/egusphere-egu23-11849, 2023.

X4.209
|
EGU23-5242
|
ST1.4
Adnane Osmane

Radial diffusion in planetary radiation belts is a dominant transport mechanism resulting in the energisation and loss processes of charged particles by ultra-low frequency (ULF) fluctuations in the Pc4-Pc5 range. The theoretical framework upon which radial diffusion coefficients have been analytically derived in the past 60 years belongs to various types of quasi-linear theories. In quasi-linear theories, the evolution equation for the distribution function experiencing radial diffusion is only valid on slow timescales longer than the characteristic period of the ULF waves and the azimuthal drift period of the particles, ranging from tens of minutes to a few hours for electrons with energies between tens of keV to several hundreds of keV. Therefore, radiation belts’ dynamical processes occurring on fast timescales comparable to ULF wave periods or azimuthal drift periods, such as fast magnetopause losses localised in magnetic local time (MLT), cannot self-consistently be quantified in terms of radial diffusion models. In this communication, we present a new theoretical framework based on drift kinetic (Hazeltine, 1973) to distinguish between the fast and slow response of energetic electrons to ULF waves. We conclude our talk with two examples to demonstrate the benefits of the drift kinetics approach: 1) fast electron losses due to MLT localised compression of the magnetopause, and 2) non-diffusive acceleration associated with symmetric ULF fluctuation.  

How to cite: Osmane, A.: A new theoretical framework to model radial transport of energetic particles by ULF waves in the Earth's magnetosphere., EGU General Assembly 2023, Vienna, Austria, 23–28 Apr 2023, EGU23-5242, https://doi.org/10.5194/egusphere-egu23-5242, 2023.

Posters virtual: Thu, 27 Apr, 14:00–15:45 | vHall ST/PS

Chairpersons: Rumi Nakamura, Jonathan Rae, Chris Arridge
vSP.1
|
EGU23-15055
|
ST1.4
Patrick Antolin and Clara Froment

Cool plasmas (≈ 104 K) embedded in a larger, much hotter (>106 K) medium are ubiquitous in different astrophysical systems such as solar & stellar coronae, the circumgalactic (CGM), interstellar (ISM) and intra-cluster (ICM) media. The role of these multiphase plasmas has been highlighted in mass-energy cycles at all such scales, from thermal non-equilibrium (TNE) cycles in the solar atmosphere to precipitation-regulated feedback cycles that drive star and galaxy formation. The properties of the cool plasmas across these multiple scales is strikingly similar, intimately linked to the yet unclear but fundamental mechanisms of coronal and ICM heating and instabilities of thermal or other nature. The solar corona constitutes a formidable and unique astrophysics laboratory where we can spatially and temporally resolve the physics of such multiphase plasma. The multi-faceted and measured response of the solar atmosphere to the heating is exemplified by TNE cycles that manifest through EUV intensity pulsations and through the generation of cool coronal rain and prominences whose mysterious properties are like that of multiphase filamentary structure in the ISM and ICM or to molecular loops in the Galactic centre. Coronal rain also occurs across a wide energetic scale extending to flares, whose features seem recurrent in active stars but remains poorly investigated due to lack of multi-temperature coverage at appropriate resolution. The formation and stability-loss of prominences is of major importance to space weather and their ‘slingshot’ counterparts provide unique diagnostic capabilities to the wind mass-loss rate. These exciting new cross-disciplinary possibilities are part of a Heliophysics Decadal Survey white paper and call for a high-resolution multi-wavelength imaging and spectroscopic solar instrument able to capture the multithermal, dynamic and pervasive nature of the multiphase plasma in the hot solar corona.

How to cite: Antolin, P. and Froment, C.: Cool Multiphase Plasma in Hot Environments, EGU General Assembly 2023, Vienna, Austria, 23–28 Apr 2023, EGU23-15055, https://doi.org/10.5194/egusphere-egu23-15055, 2023.

vSP.2
|
EGU23-15289
|
ST1.4
Mark Cheung, Ron Ekers, John Morgan, Rajan Chhetri, Angelica Waszewski, George Hobbs, Dilpreet Kaur, Andrew Zic, Ramesh Bhat, and Meng Jin

CSIRO, Australia's national science agency, operates a number of world-class radio astronomy observatories that are collectively known as the Australia Telescope National Facility (ATNF). The facility offers a powerful view of the southern hemisphere radio spectrum and supports world-leading research by Australian and international astronomers. Decades after the Culgoora Radioheliograph made fundamental discoveries about solar radio bursts, a new generation of radio telescopes in Australia are providing unique measurement capabilities to address outstanding questions in Heliophysics. Inyarrimanha Ilgari Bundara (“Sharing the Sky and Stars”), the CSIRO Murchison Radio-astronomy Observatory in Western Australia, is home to the Murchison Widefield Array (operated by a consortium led by Curtin University), the Australian Square Kilometre Array Pathfinder (ASKAP), and the future home of the Square Kilometre Array (SKA)-Low Telescope. Interplanetary scintillation (IPS) measurements by these radio telescope arrays will provide important observational constraints of the solar wind and interplanetary coronal mass ejections (ICMEs). This is enabled by simultaneous detections of a high density of scintillating sources over a wide field of view. Complementarily, Parkes Radio Telescope observations towards pulsars may provide density and magnetic field diagnostics of the corona and solar wind. In addition, radio observations toward exoplanet host stars give important constraints on the habitability of exoplanets. In this presentation, we will introduce the facilities, relevant radio astronomical diagnostics, early results, and plans for using the observations for data assimilation. 

How to cite: Cheung, M., Ekers, R., Morgan, J., Chhetri, R., Waszewski, A., Hobbs, G., Kaur, D., Zic, A., Bhat, R., and Jin, M.: Space Weather with Radio Telescopes in Australia, EGU General Assembly 2023, Vienna, Austria, 23–28 Apr 2023, EGU23-15289, https://doi.org/10.5194/egusphere-egu23-15289, 2023.

vSP.3
|
EGU23-7030
|
ST1.4
|
Chao Shen

Space plasmas are composed of charged particles that play a key role in electromagnetic dynamics. However, to date, there has been no direct measurement of the distribution of such charges in space. In this study, three schemes for measuring charge densities in space are presented. The first scheme is based on electric field measurements by multiple spacecraft. This method is applied to deduce the charge density distribution within Earth’s magnetopause boundary layer using Magnetospheric MultiScale constellation (MMS) 4-point measurements, and indicates the existence of a charge separation there. The second and third schemes proposed are both based on electric potential measurements from multiple electric probes. The second scheme, which requires 10 or more electric potential probes, can yield the net charge density to first-order accuracy, while the third scheme, which makes use of seven to eight specifically distributed probes, can give the net charge density with second-order accuracy. The feasibility, reliability, and accuracy of these three schemes are successfully verified for a charged-ball model. These charge density measurement schemes could potentially be applied in both space exploration and ground-based laboratory experiments.

 

How to cite: Shen, C.: Measuring the Net Charge Density of Space Plasmas, EGU General Assembly 2023, Vienna, Austria, 23–28 Apr 2023, EGU23-7030, https://doi.org/10.5194/egusphere-egu23-7030, 2023.

vSP.4
|
EGU23-7436
|
ST1.4
|
Graziella Branduardi-Raymont

How does solar wind energy flow through the Earths magnetosphere, how is it converted and distributed? This are the questions we want to address. We need to understand how geomagnetic storms and substorms start and grow, not just as a matter of scientific curiosity, but to address a clear and pressing practical problem: space weather, which can influence the performance and reliability of our technological systems, in space and on the ground, and can endanger human life and health.

Much knowledge has already been acquired over the past decades, particularly by making use of multiple spacecraft measuring conditions in situ, but the infant stage of space weather forecasting demonstrates that we still have a vast amount of learning to do. A novel global approach is now being taken by a number of space imaging missions which are under development and the first tantalising results of their exploration will be available in the next decade. In a White Paper, submitted to ESA in response to the Voyage 2050 Call, we propose the next step in the quest for a complete understanding of how the Sun controls the Earth’s plasma environment: a tomographic imaging approach comprising two spacecraft in highly inclined polar orbits, enabling global imaging of magnetopause and cusps in soft X-rays, of auroral regions in FUV, of plasmasphere and ring current in EUV and ENA (Energetic Neutral Atoms), alongside in situ measurements. Such a mission, encompassing the variety of physical processes determining the conditions of geospace, will be crucial on the way to achieving scientific closure on the question of solar-terrestrial interactions.

The White Paper was published on 16 August 2021 (G. Branduardi-Raymont et al., Experimental Astronomy, https://doi.org/10.1007/s10686-021-09784-y) and full co-author details are at the end of the article.

How to cite: Branduardi-Raymont, G.: Exploring solar-terrestrial interactions via multiple imaging observers, EGU General Assembly 2023, Vienna, Austria, 23–28 Apr 2023, EGU23-7436, https://doi.org/10.5194/egusphere-egu23-7436, 2023.

vSP.5
|
EGU23-16422
|
ST1.4
|
Gabriella Stenberg Wieser, Masatoshi Yamauchi, and Moa Persson

Recent Venus missions (Venus Express and Akatsuki) provided a large-scale view of Venus atmosphere and discovered new phenomena, such as high-altitude extension of the mountain wave to the cloud layer and a dawn-dusk asymmetry in the ionospheric motion.  The superrotation of the cloud layer is assumed to be driven by the thermal tide but its relation to any meridional convection or waves is still unknown.  The key to understand all these phenomena is to determine the multi-step re-distribution of the absorbed solar radiation to other forms of energy: (1) internal energy; including temperature, latent heat, and chemical energy (2) kinetic energy both in large scale flows/waves and in minor deviations of convection motions, (3) electric energy including ionization.

To understand how the motion of Venus atmosphere is driven by the energy originating from the absorption of solar radiation, we proposed Venus Dynamics Tracer (VdT), a mission for in-situ measurements, as a response to the ESA call for new M-class missions.  Specific targets were two major energy absorption regions: the cloud layer and the ionized upper atmosphere. The scientific goals were to investigate (a) the roles of the vertical and meridional circulation in maintaining major atmospheric dynamics near the cloud layer where visible light is absorbed and drives the vertical motions of the air, and to understand the (b) global dynamics of ions and neutrals in the upper atmosphere where EUV is absorbed both by neutrals and ions and where energy and momentum are transferred between them. 

For the first target, multiple-balloons are deployed for in situ observations with supporting camera/s on an orbiter giving global context. For the second target, the motions of ions and neutrals are directly measured.  This presentation discusses required measurements to answer the scientific goals.  

How to cite: Stenberg Wieser, G., Yamauchi, M., and Persson, M.: Venus Dynamics Tracer (VdT) - a mission dedicated for in-situ measurements of the Venus atmosphere., EGU General Assembly 2023, Vienna, Austria, 23–28 Apr 2023, EGU23-16422, https://doi.org/10.5194/egusphere-egu23-16422, 2023.

vSP.6
|
EGU23-8410
|
ST1.4
|
Yoshifumi Saito, Yoshizumi Miyoshi, Kanako Seki, and Shinsuke Imada

Toward the inner Heliospheric system science exploration in the late 2020s, ISAS/JAXA is currently operating the Arase, BepiColombo/Mio, Hinode, and Akatsuki satellites, and Solar-C EUVST is scheduled for launch in the near future. These missions will be linked together with other satellite missions such as Solar-Orbiter, Solar Parker Probe, Cluster, THEMIS, MMS etc. to realize exploration of the inner Heliosphere with unprecedented scale.

In the early 2030s, Japanese Solar Terrestrial Physics group is considering the FACTORS formation-flight satellite mission in order to reveal the energy coupling mechanisms and mass transport between the space and Earth’s atmosphere. In the late 2030s, another formation-flight magnetospheric satellite mission the science target of which includes understanding the cross-scale / cross-region coupling is also under consideration hopefully on orbit at the same time with European future mission Plasma Observatory. These future missions will closely collaborate with NASA’s future GDC and Magnetospheric Constellation missions.

The future Heliospheric system science exploration will be conducted by multiple satellite missions further expanding their observation area while improving the quality of each individual satellite mission. Japanese Solar Terrestrial Physics group will conduct in-situ observation of space plasmas with MMX (Martian Moons Exploration) and MIM(Mars Ice Mapper) in the Martian system and with JUICE (Jupiter Icy Moons Explorer) in the Jovian system. Collaboration between Japanese Solar Physics and Solar Terrestrial Physics groups for considering the future out-of-ecliptic-plane mission is also about to start.

In order to realize the future Heliospheric system science exploration, significant technological development is mandatory. Current status of the technological development in Japan for enabling the future Heliospheric system science exploration will also be presented.

How to cite: Saito, Y., Miyoshi, Y., Seki, K., and Imada, S.: Future Heliospheric System Science Exploration in Japan, EGU General Assembly 2023, Vienna, Austria, 23–28 Apr 2023, EGU23-8410, https://doi.org/10.5194/egusphere-egu23-8410, 2023.