Stellar eruptions in the form of coronal mass ejections (CME) often result in major impact on planets. In this talk, we will visualize stellar-planet connections based on simulations and observations of the April 2023 and May 2024 CMEs. Both CME events resulted in extreme geomagnetic responses. In-situ measurements such as those from the Magnetospheric Multiscale mission enabled a new view of Sun-Earth magnetic connection and the CME space weather impact. We will explore the CME multi-messenger impact on multiple planets. Highlight will include the transformation of Earth's magnetosphere from a usual windsock-like configuration with a long magnetotail to one with wings and no tail. We will see first-hand how solar-magnetosphere research carries the power to advance planetary and star-exoplanet science.
How to cite: Chen, L.-J.: Star-planet connection visualized through the April 2023 and May 2024 coronal-mass-ejection driven storms, EGU General Assembly 2025, Vienna, Austria, 27 Apr–2 May 2025, EGU25-20047, https://doi.org/10.5194/egusphere-egu25-20047, 2025.
Space weather significantly impacts the Earth’s magnetic field and can severely disrupt power systems. As modern society increasingly relies on power systems, space weather effects cascade into other sectors, with severe events posing catastrophic economic risks. Research on the economic losses caused by space weather remains in its early stages, leading to potential inadequacies in risk assessment and mitigation measures and heightening the vulnerability of economic and social systems. This study employs the Dynamic Inoperability Input-Output Model to assess the GDP impact of geomagnetic storms in the United Kingdom with an occurrence rate of 1-in-11 to 1-in-1,000,000 years. We also use the Vector Autoregression model to analyze the impact of geomagnetic disturbances on the operability of the power grid of Switzerland. Results indicate that a geomagnetic "superstorm" with an occurrence rate of 1-in-10,000 to 1-in-1,000,000 years could lead to GDP losses of 7.22%-52.3%, while the total GDP loss of a Québec-scale storm would fall in the range of 3.9%-5.6%. In Switzerland, GICs negatively affect power generation, transmission, and prices, with disruptions lasting days. These findings provide a foundation for policymakers to devise strategies to mitigate the risks of extreme space weather events.
How to cite: Yin, T., Yuan, D., Chen, W., and Xue, F.: The impact of space weather on the national-scale power grid and the associated economic losses, EGU General Assembly 2025, Vienna, Austria, 27 Apr–2 May 2025, EGU25-3137, https://doi.org/10.5194/egusphere-egu25-3137, 2025.
The Prediction of Adverse effects of Geomagnetic storms and Energetic Radiation (PAGER) project provides space weather predictions initiated from observations of the Sun, offering forecasts of radiation in space and its effects on satellite infrastructure. Real-time predictions enable the evaluation of surface charging and deep dielectric charging, critical for satellite operations. PAGER provides 1–4-day probabilistic forecasts of the ring current and radiation belt environments, allowing satellite operators to respond to significant threats effectively.
We present models of solar superstorms. We provide and rigorously evaluate probabilistic predictions, demonstrating how data assimilation can significantly improve forecasting accuracy. Leveraging the most advanced codes from the US and Europe, the project performs ensemble simulations and uncertainty quantifications. These innovations, including data assimilation and machine learning, not only enhance current predictive capabilities but also lay the groundwork for realistic modeling of extreme space weather events from the Sun to the Earth’s ionosphere allowing for the data to correct for missing physical processes.
How to cite: Kendall, E. and Shprits, Y. Y. and the PAGER team: Prediction of Adverse effects of Geomagnetic storms and Energetic Radiation (PAGER) , EGU General Assembly 2025, Vienna, Austria, 27 Apr–2 May 2025, EGU25-18619, https://doi.org/10.5194/egusphere-egu25-18619, 2025.
The complex and variable interaction between the conducting Martian ionosphere and the incoming solar wind causes the draping of interplanetary magnetic field (IMF) lines around Mars, giving rise to a weak induced magnetosphere (IM) despite the planet’s lack of a global intrinsic magnetic field. The weak magnetic field is a result of induced ionospheric currents and a nearly perpetual dynamic feature of the Martian magnetic topology. This draping of IMF lines can be observed at the crossing of the magnetic pile-up plasma boundary (MPB), defined by a characteristic increase in magnetic field magnitude and attenuation in fluctuations, along with a significant decrease in the density of 1 keV protons. Alternatively known as the induced magnetosphere boundary (IMB), the MPB marks the separation between the magnetosheath and the Martian induced magnetosphere. We visually inspected the magnetic field and plasma data collected by the MAG, SWEA, and SWIA instruments on the Mars Atmosphere and Volatile EvolutioN (MAVEN) spacecraft in 2018, and found unusual isolated occurrences of unchanged or dropping magnetic field intensity during high solar zenith angle MPB crossings. These observations are interpreted as “disappearing” MPR phenomena as the magnetic pile-up signature is not observed, suggesting a reduced pile-up of IMF around Mars. Previous observations on Venus have attributed absences in the dayside IM to radial IMF orientation during extreme solar wind conditions, hampering magnetic draping as the flow of solar wind is close to aligned with the IMF (Zhang et al., 2009). Preliminary analysis of hourly cadence solar wind predictions reveals that this may also be true at Mars, potentially explaining some of the events. However, the Martian magnetosphere is shown to respond to solar wind fluctuations in a matter of minutes, making it important to explore higher resolution data and examine fluctuations on that scale to establish correlations and determine if this is an externally driven phenomenon or driven within the system itself instead. We will also discuss the concurrent development of a recurrent neural network (RNN) with long short-term memory (LSTM) architecture, which will aid in expanding the non-pile-up dataset to the 10 years of MAVEN data for a more robust investigation into the origin of MPR “disappearance”.
How to cite: Abreu, M., Poh, G., Koh, Z.-W., Ma, Y., Gruesbeck, J., DiBraccio, G., and Espley, J.: The Vanishing Martian Magnetic Pile-up Region: Probing Radial IMF Causality using MAVEN Measurements, EGU General Assembly 2025, Vienna, Austria, 27 Apr–2 May 2025, EGU25-13797, https://doi.org/10.5194/egusphere-egu25-13797, 2025.
Near perihelion, when comet 67P was most active, the Rosetta spacecraft resided inside the comet induced magnetosphere. The solar wind magnetic field was still present, but the solar wind ions were mostly gone, Rosetta was in the solar wind ion cavity. The solar wind was not completely gone though, there were sporadic occurrences of solar wind ions. Observations from this period shed light on the solar wind - comet interaction for a medium activity comet. Such a medium activity comet is the likely target of the Comet Interceptor mission so a better understanding of the environment will help planning plasma observations for that mission. Solar wind ions flowing consistently anti-sunward were seen, indicating a fully developed cometosheath pushed closer to the nucleus. The speed of the solar wind in the cometosheath was typically around 200 km/s with a broad angular distribution. One-dimensional temperature estimates from direction integrated energy spectra indicate mostly little if any heating of the solar wind protons in the cometosheath. There are sporadic exceptions and we discuss whether these high proton temperature observations could be due to the interaction of the solar wind with the comet environment or is due to a coronal mass ejection or coronating interaction region. We compare the observations with hybrid model results.
How to cite: Nilsson, H., Stenberg Wieser, G., Williamson, H., Möslinger, A., Gunell, H., and Fatemi, S.: Solar wind interaction with comet 67P around perihelion - the formation of a cometosheath, EGU General Assembly 2025, Vienna, Austria, 27 Apr–2 May 2025, EGU25-8733, https://doi.org/10.5194/egusphere-egu25-8733, 2025.
The Radiation Assessment Detector (RAD) onboard the Mars Science Laboratory’s Curiosity rover has continuously monitored energetic particles on the Martian surface since its landing on August 6, 2012. The resulting dataset provides a unique opportunity to study the Martian radiation
environment across a complete solar cycle.
Understanding this environment is crucial for evaluating the risks associated with future manned space missions and for advancing research into planetary conditions, solar activity, and galactic cosmic rays (GCRs).
Radiation on the Martian surface comprises primary GCRs and secondary particles produced through interactions of GCRs with the atmosphere or soil. These radiation levels exhibit temporal variations influenced by factors such as atmospheric changes, thermal tides, seasonal cycles, shielding effects, heliospheric modulation of GCRs, and the physical properties of Martian soil. Capturing these variations requires a holistic approach that integrates long-term trends and localized phenomena.
In this study, we utilize the extensive dataset collected by the RAD over the past 12 years to investigate the intricate variations in particle flux on Mars. Our analysis spans a diverse array of particle species, enabling a comprehensive understanding of how particle flux evolves throughout
an entire solar cycle. This extended temporal coverage allows us to identify and analyze long-term trends, shedding light on the dynamic nature of particle interactions within the Martian environment.
We explore the effects of solar activity, atmospheric dynamics, and surface shielding on the radiation environment, while also examining the role of subsurface materials in generating upward moving secondary particles. These findings provide valuable insights into the potential water con
tent and geological features beneath the Martian surface. By delving into the temporal patterns of particle flux across di erent species, this work aims to advance our understanding of the complex radiation dynamics on Mars and their implications for future human exploration and potential
habitation.
How to cite: Khaksarighiri, S., Löwe, J. L., Wimmer-Schweingruber, R. F., Guo, J., Hassler, D. M., Ehresmann, B., Zeitlin, C., Matthiä, D., Berger, T., Reitz, G., and Löffler, S.: Radiation Environment on Mars: Insights from 12 Years of Curiosity’s RAD Observations, EGU General Assembly 2025, Vienna, Austria, 27 Apr–2 May 2025, EGU25-11041, https://doi.org/10.5194/egusphere-egu25-11041, 2025.
Venus lacks an intrinsic magnetic field, and its interaction with the solar wind and interplanetary magnetic field (IMF) creates an induced magnetosphere [1]. The IMF drapes around the planet, forming the magnetotail on Venus’ nightside, the main channel through which the ionospheric plasma escapes [2]. However, the ion escape in the magnetotail is reduced by unexplained flows that come back to Venus, i.e., return flows [3]. The process responsible for reversing the velocity of magnetotail ions remains unsolved.
A possible mechanism causing the return flows is magnetic reconnection, a plasma process triggered by antiparallel magnetic field lines in the Venusian magnetotail. A plasmoid flowing toward Venus can be produced by reconnection. Such magnetic reconnection events have been identified by magnetic and plasma data collected by the Venus Express (VEX) spacecraft [4].
Here, we reassessed the VEX’s magnetometer (MAG) [5] and electron data using ASPERA-4/ELS [6] throughout the mission to identify typical Hall magnetic field signatures when the spacecraft crosses the plasma sheet, as well as electron energization, as evidence of the magnetic reconnection events [7]. We also systematically reassessed ion data (ASPERA-4/IMA) to identify return flow events when the ions are traveling in the direction toward Venus.
In this presentation, we show several cases where we simultaneously detected the magnetic Hall field signature and ion return flows. These events are strong candidates for ion return flow associated with magnetic reconnection in the Venusian magnetotail. The ion speeds during these events are consistent with those predicted by reconnection theory. We will discuss the magnetic reconnection events and their possible role in triggering return flows in Venus’ magnetotail.
[1] Futaana, Y., Stenberg Wieser, G., Barabash, S., & Luhmann, G. J. 2017, SSR, 212, 1453, doi: 10.1007/s11214-017-0362-8
[2] Dubinin, E., Fränz, M., Zhang, T. L., et al. 2013, JGR, 118, 7624, doi: 10.1002/2013JA019164
[3] Persson, M., Futaana, Y., Fedorov, A., et al. 2018, GRL, 45, 10805, doi: 10.1029/2018GL079454
[4] Zhang, T.-L., Baumjohann, W., Lu, Q. M., et al. 2012, Science, 336, 567, doi: 10.1126/science.
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[5] Zhang, T.-L., Berghofer, G., Magnes, W., et al. 2007, ESA Special Publication SP 1295 (Paris: ESA)
[6] Barabash, S., Sauvaud, J., Gunell, H., et al. 2007, PSS, 55, 1772, doi: 10.1016/j.pss.2007.01.014
[7] Yamada, M., Kulsrud, R., & Ji, H. 2010, RvMP, 82, 603, doi: 10.1103/RevModPhys.82.603
How to cite: Rollero, U., Futaana, Y., and Wang, X.-D.: Magnetic reconnection and return flows in Venus’ magnetotail: case studies for Venus Express data, EGU General Assembly 2025, Vienna, Austria, 27 Apr–2 May 2025, EGU25-8131, https://doi.org/10.5194/egusphere-egu25-8131, 2025.
The Martian ionosphere is primarily influenced by solar radiation on the dayside, while on the nightside, it is controlled by impact ionization from precipitating particles and the transport of ions from the dayside. Occasionally, the ionosphere exhibits abrupt plasma density reductions—characterized by an order-of-magnitude decrease relative to the background—referred to as Plasma Depletion Events (PDEs). These events, often accompanied by elevated electron temperatures and electrostatic fluctuations, are poorly understood yet potentially critical to understanding ion escape and ionospheric variability. Characterizing their dimensions, recurrence, and temporal behavior provides valuable insight into the plasma environment of Mars. This study investigates over 1,000 PDEs detected by the Mars Atmosphere and Volatile Evolution (MAVEN) spacecraft between October 2014 and May 2021. By analyzing recurring MAVEN orbits, we identify 80 PDEs reappearing at the same locations within 18 to 30 hours, suggesting that these events may recur periodically. Additionally, conjugate observations by MAVEN and Mars Express reveal that PDEs can span up to 750 km and persist for several hours. These findings suggest PDEs to be large-scale, recurring phenomena with implications for plasma instabilities, ion escape, and Martian ionospheric dynamics.
How to cite: Basuvaraj, P., Nemec, F., Fowler, C. M., Regoli, L. H., Nemecek, Z., Safrankova, J., Witasse, O., and Wilson, C. F.: Characterizing Plasma Depletion Events on Mars: Spatial and Temporal Dynamics from MAVEN and Mars Express, EGU General Assembly 2025, Vienna, Austria, 27 Apr–2 May 2025, EGU25-5148, https://doi.org/10.5194/egusphere-egu25-5148, 2025.
The Martian magnetotail current sheet shares characteristics with its terrestrial counterpart and serves as a critical pathway for the escape of ionospheric ions. Understanding this process is vital for reconstructing the historical evolution of Mars' atmosphere. In this study, we report on an unique Martian current sheet where the thermal pressure of electrons, rather than ions, counterbalances the ambient magnetic pressure. Our numerical analysis indicates that electron heating within the current sheet is predominantly driven by magnetosonic waves via Landau resonance. These waves are likely generated in the upstream magnetosheath region. Our results highlight the crucial role of wave-particle interactions in shaping the plasma environment around Mars.
How to cite: Yu, L. and Su, Z.: Landau heating of Martian tail current sheet electrons by magnetosonic waves, EGU General Assembly 2025, Vienna, Austria, 27 Apr–2 May 2025, EGU25-9661, https://doi.org/10.5194/egusphere-egu25-9661, 2025.
The nightside ionosphere of Mars is formed by plasma transport from the dayside and electron precipitation. Significant progress has been made in our understanding of its composition and structure at low altitudes, however, what happens at higher altitudes remains unclear. Plasma structures escaping from the nightside of Mars could reveal the plasma transport paths from the dayside and from the nightside to space. Furthermore, the response of escaping plasma structures to changing solar wind conditions will shed light on the dynamic evolution of the system. Mapping the paths of escaping plasma structures will result in a better understanding of the evolution of atmospheric escape at Mars and the contribution of escaping plasma structures to the total atmospheric loss. In this study we probe escaping plasma structures utilising two special campaigns of ESA's Mars Express mission as well as observations from NASA's MAVEN mission, in the high-altitude nightside ionosphere of Mars. Mars Advanced Radar for Subsurface and Ionosphere Sounding (MARSIS) is the radar on board Mars Express and it typically samples the ionosphere at altitudes no higher than ~1500 km. In our study we look at observations from consecutive orbits during two special MARSIS campaigns, each consisting of 5 orbits, that took place in September 2023 and April 2024, for which MARSIS was operated at altitudes up to 4000 km.
We see a variable nightside ionosphere at high altitudes that changes between consecutive Mars Express orbits. MARSIS detects plasma structures, appearing at different altitudes or disappearing between orbits, although a consistent plasma presence in the terminator region is observed. We compare the observations from the special MARSIS campaigns with MAVEN measurements to better evaluate both the escaping plasma structures and the solar wind conditions. MAVEN too sees plasma structures at high altitudes on the nightside, changing between orbits, confirming the variability in the nightside ionosphere. Combining Mars Express and MAVEN data we further investigate the effect of changing solar wind conditions to the plasma structures.
How to cite: Stergiopoulou, K., Lester, M., Joyce, S., and Andrews, D.: Escaping plasma structures in the Martian magnetotail as observed during two special MARSIS high-altitude campaigns, EGU General Assembly 2025, Vienna, Austria, 27 Apr–2 May 2025, EGU25-1027, https://doi.org/10.5194/egusphere-egu25-1027, 2025.
This study comparatively investigates two sets of eruptive solar events in late 2023 which occurred in two episodes with similar eruption characteristics, separated by a full solar rotation. The solar activity periods cover October 31–November 3 and November 27–28. Both episodes were linked to intense geomagnetic storms, on November 4–5 and December 1–2, respectively, with strongest effects on November 5. In detail we find that the first episode produced visible Stable Auroral Red (SAR) arcs and a three-step decline in the Dst index to −163 nT. This event involved two CME-related shocks, a sector boundary crossing (SBC), and a short-duration flux rope. The second episode led to auroral lights and a two-step Dst index drop to −108 nT, featuring a shock within another CME's magnetic structure, combined with a SBC and a clear flux rope structure. Both events displayed short-term magnetic field variations and fluctuations in density and temperature post-SBC.
Our comparative analysis highlights the role of interacting CME structures, and the modulation effects of magnetic structures related to SBCs, contributing to the stronger geomagnetic impact observed in the November 4–5 event. Additionally, the highly tilted orientation of the heliospheric current sheet likely intensified the interactions with the CMEs, enhancing their geomagnetic influence.
How to cite: Temmer, M., Dumbovic, M., Martinic, K., Cappello, G., Remeshan, A., Matkovic, F., Milosic, D., Koller, F., and Calogovic, J.: Analyzing the Geomagnetic Impact of Interacting CMEs and Sector Boundary Crossings During Autumn 2023 Eruptive Events, EGU General Assembly 2025, Vienna, Austria, 27 Apr–2 May 2025, EGU25-4178, https://doi.org/10.5194/egusphere-egu25-4178, 2025.
The Martian magnetosphere is unique in our Solar system because it contains components of an induced and an intrinsic magnetosphere. Since we can not get a global snapshot of the magnetosphere at a given time we use a statistical picture based on a large number of plasma measurements. Depending on the choice of coordinate system used and the selection of the data we can observe different features of the Martian magnetosphere. If, for example, we map data in the Martian Solar Electric (MSE) coordinate system with a fixed direction of the cross-flow component of the interplanetary magnetic field (IMF), then we can separate the induced features of the magnetosphere of Mars which appears similar to the magnetosphere of Venus. If we map data in the geographic coordinate system, then effects caused by the local crustal magnetic field are emphasized and we can observe a mini crustal magnetosphere. If we use the Martian Solar Orbital (MSO) coordinate system and select together the spacecraft orbits with positive and negative By-component of the IMF, then the effects related to draped magnetic field and the high order harmonics of the crustal magnetic field are significantly weakened because of averaging over many spacecraft orbits. In this case, a dipole-like magnetosphere of Mars becomes visible indicating the existence of a weak planetary dipole field. If we select separately the orbits with positive and negative By-component of the IMF we observe a twist of the magnetotail in the direction determined by the sign of By that is typical for a hybrid magnetosphere with the induced and intrinsic components. The intrinsic and induced components are also well separated when we select the orbits with northward IMF. Then we observe the features that are somewhat similar to those at the Earth magnetosphere. When we use the MSO coordinates and separate by the phase of Mars rotation, the tail topology occurs more complex. This indicates that the effects of the local crustal magnetic field turn out as being also important.
How to cite: Dubinin, E., Fraenz, M., Modolo, R., Paetzold, M., Tellmann, S., and DiBraccio, G.: A dipole-like magnetosphere of Mars, EGU General Assembly 2025, Vienna, Austria, 27 Apr–2 May 2025, EGU25-5940, https://doi.org/10.5194/egusphere-egu25-5940, 2025.
Using data from the Mars Atmosphere and Volatile Evolution (MAVEN) mission we investigate the flapping dynamics of the Martian bow shock (BS). While awaiting future dedicated two-spacecraft missions, we make use of the large number of single-spacecraft crossings from MAVEN to conduct a statistical study on observed multiple BS crossings.
The Martian bow shock has been studied extensively in the past, with a focus primarily on its formation, location, shape, and controlling factors. However, its dynamic motion, particularly flapping behavior, has received less attention - understandable given the constraints of single-spacecraft observations. From time series of magnetic field data, BS flapping, i.e. multiple crossings in a row, is observed in roughly 20% of all MAVEN orbits the first two years of the mission, which are investigated here. The multiple crossings are interpreted as a spatial change of the BS, moving in and out past the spacecraft. Preliminary analysis shows that the occurrence rate of the flapping is higher in the flank region compared to the ram side, but is otherwise evenly distributed around Mars. We find no preference for south or north hemisphere, and no dependence on the convective electric field direction. The median duration between two successive crossings is approximately 2 minutes. Estimates of the shock velocity from mass flux conservation laws during flapping events indicate that the BS moves faster on the dayside than on the flank. Flapping is more prevalent when the BS is quasi-perpendicular (75% of the cases) than when it is quasi-parallel (25% of cases). The closer to the planet the more quasi-parallel cases are found. The flapping does not seem to depend on the orbit-averaged solar wind dynamic pressure or magnetosonic Mach number values, as those parameters influence the BS on shorter time scales, as shown by Cheng et al., (2023).
These findings underscore the dynamic and complex nature of the Martian bow shock and enhance our understanding of its interaction with the solar wind. The results might have implications for energy transfer processes in weakly magnetized planetary systems and provide valuable context for comparative studies of bow shock dynamics across other planetary environments.
How to cite: Edberg, N. J. T., Andrews, D. J., Cheng, L., Kim, K., Stergiopoulou, K., Lester, M., Simon Wedlund, C., Halekas, J., and Curry, S. M.: Statistical analysis of the movement of the Martian bow shock, EGU General Assembly 2025, Vienna, Austria, 27 Apr–2 May 2025, EGU25-6575, https://doi.org/10.5194/egusphere-egu25-6575, 2025.
Accurate space weather forecasting is essential for mitigating the risks posed by geomagnetic storms to technological systems, particularly satellites. The PAGER project provides an advanced probabilistic framework for space weather prediction, employing state-of-the-art ensemble simulations to forecast solar wind parameters, ring current dynamics, and the radiation belt environment. By leveraging cutting-edge models, data assimilation techniques, and uncertainty quantification, PAGER produces forecasts of Kp and Hpo indeces, cold plasma density, and relativistic electron fluxes, addressing both surface charging and deep dielectric charging risks to satellite infrastructure.
In this study, we utilize the PAGER framework to simulate the 2024 Mother's Day Solar Storm. The simulation is initialized with GONG magnetogram data, which provides the boundary conditions for ensemble solar wind predictions at L1. These predictions include solar wind velocity, proton density, and magnetic field components. By comparing simulation outputs to in-situ observations from the OMNIWeb database, we assess the predictive accuracy of PAGER's ensemble forecasting capabilities. Additionally, we demonstrate the integration of these solar wind predictions with radiation belt and satellite charging models, illustrating PAGER's capacity to link solar wind dynamics with downstream effects in the Earth's magnetosphere and their impact on satellite operations.
PAGER's ensemble approach incorporates sophisticated models of magnetospheric dynamics and ring current evolution, offering critical insight into the radiation environment surrounding Earth during extreme space weather events. This study will highlight the ensemble predictions for the Mother's Day Solar Storm and demonstrate PAGER's broader capability to address uncertainty in space weather forecasting, thus enhancing our ability to protect satellite infrastructure from adverse space weather effects.
How to cite: Shirke, A., Shprits, Y., Wang, D., Haas, B., and Bianco, S.: PAGER : Space Weather Prediction and Ensemble Forecasting for the 2024 Mother's Day Solar Storm, EGU General Assembly 2025, Vienna, Austria, 27 Apr–2 May 2025, EGU25-9759, https://doi.org/10.5194/egusphere-egu25-9759, 2025.
The interaction between solar wind and unmagnetized planets, exemplified by Venus and Mars, is a significant issue in planetary sciences. The absence of global intrinsic magnetic fields on these planets results in the formation of complex and unique induced magnetospheric environments due to their interactions with the solar wind. Our study aims to systematically analyze scientific data obtained from planetary space missions to investigate the dynamic magnetic field environments within these induced magnetospheres, with particular emphasis on magnetic fluctuations and multiscale turbulence phenomena. We focus on characterizing the properties, propagation mechanisms, and evolutionary processes of these phenomena. To deepen our understanding of induced magnetospheric environments, we employ a comparative planetology approach, analyzing the differences and similarities between the induced magnetospheres of Venus and Mars. This comparative analysis reveals distinct features and commonalities while exploring the underlying formation mechanisms. In addition, by integrating three-dimensional magnetohydrodynamic simulations, we aim to further uncover the dynamic evolution of these turbulent magnetic environments, thereby providing a theoretical foundation for interpreting the unique space environments of unmagnetized planets. This research not only enhances our understanding of the space environments of unmagnetized planets but also offers critical scientific insights for the design and execution of future deep-space exploration missions.
How to cite: Xiao, S., Zhang, T., and Vörös, Z.: Magnetic Fluctuations and Turbulence in the Space Environments of Unmagnetized Planets: Insights from Venus and Mars, EGU General Assembly 2025, Vienna, Austria, 27 Apr–2 May 2025, EGU25-10276, https://doi.org/10.5194/egusphere-egu25-10276, 2025.
Space weather is a multi-disciplinary research area connecting scientists from across all Heliophysics domains requiring the whole global community to work together. The COSPAR International Space Weather Action Teams (ISWAT, https://iswat-cospar.org) is a global hub for open collaborations addressing challenges across the field of space weather. Groups or individuals working on a specific topic can register a new action team and open it for others to join. Action Teams are organised into ISWAT Clusters by Heliophysics domains: Sun, Heliosphere, and Coupled Geospace system. ISWAT is an effort multiplier maximising return on investments by national/regional programs. A new Sun2Geospace (S2G) Cluster is a home to action teams focused on flows of space weather processes from origins at the Sun to impacts on Geospace and connecting the various aspects of global space weather phenomena, such as Solar/Geospace storms.
In support of the multi-team-cross-domain-interdisciplinary S2G Cluster and the entire Heliophysics community the Community Coordinated Modeling Center (CCMC, https://ccmc.gsfc.nasa.gov) is building an online Portal to facilitate community-wide comparative studies of Great Solar/Geospace Storms. The Portal aims to serve as a hub for all information connecting the various aspects of the Great Storms from solar surface to impact at Earth. The Portal includes a living database continuously populated by the community. The database incorporates interactive listings of publications, presentations, links to simulation outputs and observation data. In support of the project the CCMC generated run series tailored for storm studies and collected simulation outputs, observational data and interpretations (heliostories) from a broad range of sources. CCMC tools for space weather analysis (including Integrated Space Weather Analysis – ISWA system and Database of Notifications, Knowledge Information – DONKI) have been upgraded to enable tailored layouts and listings for specific time periods. The presentation will highlight recent advances and present examples of comparative analysis focusing on Great Storms that occurred over the Heliophysics Big Year (October 2023-December 2024).
How to cite: Kuznetsova, M., Temmer, M., Kozyra, J., Bisi, M., Zheng, Y., Mays, L., Rastaetter, L., Taktakishvili, A., Wiegand, C., and Reiss, M.: Building Heliophysics Community Portal for Great Storms, EGU General Assembly 2025, Vienna, Austria, 27 Apr–2 May 2025, EGU25-19611, https://doi.org/10.5194/egusphere-egu25-19611, 2025.
How to cite: Muro, G.: Solar energetic particle ion composition of AR 13664 during the May 2024 great solar storm, EGU General Assembly 2025, Vienna, Austria, 27 Apr–2 May 2025, EGU25-17583, https://doi.org/10.5194/egusphere-egu25-17583, 2025.
In the magnetosheath of planets, mirror modes triggered by the mirror mode instability form as large magnetic structures imprisoning dense and hot plasma in their midst. The free energy created from a large pressure anisotropy at their origin can come from several sources. At Earth and other planets, the quasi-perpendicular shock provides the plasma with the necessary heating along the perpendicular direction to the local magnetic field. At Mars, the extended exosphere theoretically provides another source of temperature anisotropy, with exospheric neutrals locally ionised and subsequently picked up by local electric fields creating unstable ring-beam velocity distribution functions. Using the Mars Atmosphere and Volatile EvolutioN (MAVEN) mission plasma instrumentation, we show for the first time at Mars the unmistakable signature of near locally-generated mirror mode structures due to pickup protons. The pickup ion mechanism is reminiscent of temperature anisotropy-generating mechanisms found at comets, the outgassing moons of Jupiter, and in other heliospheric scenarios.
How to cite: Simon Wedlund, C., Mazelle, C., Meziane, K., Bertucci, C., Volwerk, M., Preisser, L., Schmid, D., Halekas, J., McFadden, J., Mitchell, D., Espley, J., and Henri, P.: On the role of pickup protons in the generation of mirror modes at Mars, EGU General Assembly 2025, Vienna, Austria, 27 Apr–2 May 2025, EGU25-8900, https://doi.org/10.5194/egusphere-egu25-8900, 2025.
Several typical asymmetries in the Venusian bow shock (BS) location, including the magnetic north-south asymmetry, the pole-equator asymmetry, and the perpendicular-parallel asymmetry, have been proven to be controlled or affected by the interplanetary magnetic field (IMF) orientation. The physical reasons behind the perpendicular-parallel shock asymmetry remain inadequately explained. Effects of ion-scale dynamics have not been adequately addressed in both previous observational data and numerical simulations. Our newly developed multi-fluid Hall-MHD model, which incorporates the convection, Hall, and ambipolar electric fields in the ion transport and magnetic induction equations, effectively captures the ion-scale dynamic effects, providing a more comprehensive understanding of the underlying processes. The model self-consistently reproduce the plasma boundaries and regions of Venus at Parker spiral angle of 15°, 36°, and 90° . The simulation results show that the subsolar standoff distance and the asymmetry of bow shock are mainly dominated by the ambipolar and Hall electric fields. As the increase of Parker spiral angle, the ambipolar electric field weakens due to that the magnetic barrier becomes wider. And intensity of the Hall electric field is significantly enhanced to affect the structure of BS and eliminate the perpendicular-parallel asymmetry. There is also an obvious perpendicular-parallel asymmetry in energy transfer rate when the Parker spiral angle is less than 90°. Our findings highlight the necessity of incorporating ion-scale dynamics into the analysis of BS asymmetry changes, offering valuable insights into the complex interactions within space plasma environments.
How to cite: Lu, H., Chen, N., Li, S., and Cao, J.: Perpendicular-Parallel Asymmetry of Venus Bow Shock Under Different Parker Spiral Angles, EGU General Assembly 2025, Vienna, Austria, 27 Apr–2 May 2025, EGU25-7980, https://doi.org/10.5194/egusphere-egu25-7980, 2025.
As the interplanetary magnetic field (IMF) carried by the solar wind encounters the martian atmosphere, it tends to pile up and drape around the planet, forming looping magnetic fields and inducing marsward ion flows on the nightside. Previous statistical observations revealed asymmetrical distribution features within this morphology; however, the underlying physical mechanism remains unclear. In this study, utilising a three-dimensional multi-fluid magnetohydrodynamic simulation model, we successfully reproduce the asymmetrical distributions of the looping magnetic fields and corresponding marsward flows on the martian nightside. Analysing the magnetic forces resulting from the bending of the IMF over the polar area, we find that the asymmetry is guided by the orientation of the solar wind motional electric field (ESW). A higher solar wind velocity leads to enhanced magnetic forces, resulting in more tightly wrapped magnetic fields with an increased efficiency in accelerating flows as they approach closer to Mars.
How to cite: Wild, J., Li, S., Lu, H., Cao, J., Cui, J., Ip, W., Zhang, X., Chen, N., Song, Y., and Wang, J.: Asymmetrical Looping Magnetic Fields and Marsward Flows on the Nightside of Mars, EGU General Assembly 2025, Vienna, Austria, 27 Apr–2 May 2025, EGU25-4871, https://doi.org/10.5194/egusphere-egu25-4871, 2025.
Posters virtual: Thu, 1 May, 14:00–15:45 | vPoster spot 3
EGU25-6228 | Posters virtual | VPS27
Finding the optimal flyby distance for the Comet Interceptor comet missionThu, 01 May, 14:00–15:45 (CEST) | vP3.12
The Comet Interceptor mission will attempt to fly by a yet undetermined target comet. The conditions of this flyby will remain largely unknown up to the selection of target and possibly even the moment of encounter. A detailed trajectory design phase, which includes verification of the technical limitations implied by the flyby geometry, precedes target comet selection, so the flyby velocity and the details of the geometry are known in advance. Solar irradiance and the neutral gas expansion speed can be estimated reasonably well. However, the comet outgassing rate, the dust production rate, and the solar wind conditions are only known within broader uncertainty margins. The present contribution aims to optimally choose the distance of closest approach based on a simplified formalism that expresses, on one hand, the science return to be expected as a function of the closest approach distance, and, on the other hand, the risks implied by a close approach. This is done by performing Monte Carlo simulations over a large sample of possible flyby configurations, based on the expected probability distributions of the gas and dust production rates and the solar wind conditions, and for different closest approach distances. For small flyby distances, a spacecraft can study the nucleus, the neutral gas coma, and the induced magnetosphere from up close, benefiting the science return. There is a trade-off to be made against the cometary dust collision risk, which becomes larger close to the nucleus. The change of the optimal flyby distance with gas and dust production rate, solar EUV flux, and flyby speed is discussed. The conclusion is that the Comet Interceptor main spacecraft and its two daughter probes – within the limitations of the approximations made – would benefit from a target comet with a gas production rate of 1028-1029 molecules·s-1, a low dust-to-gas ratio, a high solar EUV flux, and a slow flyby speed (De Keyser et al., 2024, https://doi.org/10.1016/j.pss.2024.106032), for which the optimal closest approach distance (somewhere between 300 to 2000 km for the mother spacecraft) would yield a good science return at a limited risk.
How to cite: De Keyser, J., Edberg, N. J. T., Henri, P., Rothkaehl, H., Della Corte, V., Rubin, M., Funase, R., Kasahara, S., and Snodgrass, C.: Finding the optimal flyby distance for the Comet Interceptor comet mission, EGU General Assembly 2025, Vienna, Austria, 27 Apr–2 May 2025, EGU25-6228, https://doi.org/10.5194/egusphere-egu25-6228, 2025.
EGU25-1031 | ECS | Posters virtual | VPS27
Effects of the August , 2018 CME on Mars IonosphereThu, 01 May, 14:00–15:45 (CEST) | vP3.4
The ionosphere, a natural plasma, plays a significant role in planetary satellite and communication systems and is affected by space weather events. Strong solar activities have sudden and long-term effects on the ionosphere. Ionospheric disturbances caused by these activities are considered to be one of the biggest sources of errors in satellite navigation systems and satellite communications. Both the ionosphere and magnetosphere of Mars and Earth are easily influenced by space weather conditions. Solar winds and Coronal Mass Ejections (CMEs) are among the major events influencing space weather. The ionosphere, which is highly sensitive to the effects of space weather, is much thinner and patchier on Mars compared to Earth. The rapid and intense increase in Mars missions in recent years has made today’s research more critical for future missions. In our study, we selected an August 2018 CME and examined its effects on Mars's ionosphere using the instruments on the MAVEN satellite. In addition to the SWEA, SWIA, STATIC values from the MAVEN satellite data, the height change of the relevant solar wind in the Martian ionosphere will be investigated. Investigating ionospheric disturbances with satellites like MAVEN is essential for analyzing the much thinner Martian ionosphere compared to Earth's and contributing to future Mars missions. Understanding space weather is crucial for tracking the evolution of both Earth's and the Red Planet's ionospheric structures and the long-term impact of solar flares on planetary magnetospheres.
How to cite: Dokur, A. and Can, Z.: Effects of the August , 2018 CME on Mars Ionosphere, EGU General Assembly 2025, Vienna, Austria, 27 Apr–2 May 2025, EGU25-1031, https://doi.org/10.5194/egusphere-egu25-1031, 2025.
