This session traditionally provides a forum for the discussion of all aspects of solar and heliospheric physics. Popular topics have included solar cycle dependencies of the Sun, solar wind and heliosphere, Coronal Mass Ejection research, studies of energetic particles throughout the heliosphere, and the outer boundaries of the heliosphere. We encourage contributions related to all ongoing and planned space missions, to ground-based experiments and to theoretical research. Papers presenting ideas for future space missions and experiments are very welcome in this session. The session will consist of both oral and poster presentations.

The heliosphere represents a cornerstone astrophysical laboratory where fundamental plasma processes can be investigated in situ. Understanding the origins of heliospheric variability, the mechanisms responsible for particle acceleration and particle transport, and the coupling between the solar wind and the local interstellar medium remains central to both heliophysics and astrophysics.
With its recent deployment to the Earth-Sun L1 point, NASA’s Interstellar Mapping and Acceleration Probe (IMAP) has begun delivering a new generation of observations aimed at understanding energetic particle acceleration, heliospheric structure, and the interaction between the heliosphere and the local interstellar medium. IMAP’s suite of a interstellar neutral atom detectors, for the first time, bridges the neutral atom intensity spectrum over nearly five orders of magnitude in energy, enabling unprecedented analysis of the heliospheric interaction with the local interstellar medium. Through its dedicated dust instrumentation, IMAP offers new insight into the composition, origin, and transport of interplanetary and interstellar dust grains. When combined with other spacecraft at L1, IMAP’s in situ measurements provide unique opportunities for coordinated studies of the mesoscale structure of the ambient solar wind, shocks, energetic particle events, and solar transients.
This session welcomes contributions spanning heliophysics and astrophysics, including theory, numerical modelling, and analyses of observations from current and past missions. Topics of interest include particle acceleration and particle transport from 1 au to the heliopause, the sampling and characterization of interstellar material, heliospheric boundary dynamics, and the coupling between the Sun, heliosphere, and local interstellar medium. We particularly encourage presentations featuring the first scientific results from IMAP, synergistic investigations leveraging the L1 constellation and broader heliophysics fleet, and new insights into the structure and evolution of the heliosphere across multiple spatial and temporal scales.

The Solar Orbiter mission, an international cooperation between ESA and NASA, is currently orbiting the Sun with an orbital inclination of 17° (24° from December 2026 onwards) at heliocentric distances between 0.95 to 0.29 au, providing a new perspective of the Sun’s polar regions. As the mission continues towards its max. inclination of ~33° in June 2029, it is an exciting time to study dynamics within the solar atmosphere and the inner-heliosphere from this unique perspective.

The overall goal of Solar Orbiter is to understand how the Sun creates and controls its atmosphere and the heliosphere. The mission provides unprecedented imaging of the Sun’s photosphere, chromosphere, and corona, enabling studies of the origin and evolution of the Sun’s atmosphere, the solar wind, flares, solar eruptions, and energetic particle events. The combination of high-resolution imaging and simultaneous in-situ measurements from Solar Orbiter’s inner-heliospheric vantage point offers a unique opportunity to link solar sources directly to their heliospheric impacts.

This session invites contributions that address the Solar Orbiter science objectives, exploit multi-mission data sets, and studies involving the dynamic solar atmosphere to the inner-heliosphere. We also welcome Solar Orbiter-related contributions in the fields of theory and numerical simulations that contribute to a better understanding of the solar origins of heliospheric variability and space weather.

The solar corona is the birthplace of the magnetic activity that drives the heliosphere, from flares, coronal mass ejections, and jets to waves, turbulence, and radio emissions. These processes govern coronal heating, solar wind acceleration, and the acceleration and transport of energetic particles, ultimately shaping the space weather environment throughout the heliosphere. Yet understanding their underlying physical mechanisms remains one of the fundamental challenges in heliophysics.

Over the past decade, observations from Parker Solar Probe, Solar Orbiter, PROBA-3, PUNCH, Aditya-L1, DKIST, BBSO, and complementary space- and ground-based observations have transformed our view of the near-Sun environment. Combined with advances in theory and numerical modeling, these observations have revealed the interplay of magnetic reconnection, waves, turbulence, shocks, and fine-scale plasma structuring, substantially narrowing the range of viable physical mechanisms.

This session will assess how far these advances have brought us toward resolving the long-standing problems of coronal heating, solar wind acceleration, and energetic particle acceleration and transport, while identifying the key observational, theoretical, and modeling challenges that remain. We particularly welcome contributions addressing:
• Which physical processes now appear to dominate coronal heating, and what evidence is still needed to distinguish among competing mechanisms?
• How have recent observations reshaped our understanding of solar wind acceleration, and what key questions remain?
• What progress has been made in understanding the acceleration and transport of energetic particles, and what is required to achieve predictive capability?
• How can coordinated observations and advanced modeling bridge scales from the solar atmosphere to the heliosphere?

We welcome contributions spanning observations, theory, and modeling, particularly those leveraging recent results from Parker Solar Probe, Solar Orbiter, PROBA-3, PUNCH, Aditya-L1, DKIST, and coordinated multi-mission investigations.

The heliosphere is permeated by several species of suprathermal and energetic particles (protons, electrons, heavy ions), exhibiting a diverse range of energy spectra and originating at different heliospheric and interstellar locations. Such energetic particles are of paramount importance to address many unconstrained aspects of energy conversion in astrophysical systems, as well as being impactful to society as they can pose a hazard to both human activities and technological systems in space. Suprathermal particles, in particular, are a key population that bridges the low-energy (1 keV in the heliosphere) plasma and high-energy (> 1 MeV) population, often treated independently.

The dynamics of suprathermal and energetic particles in the heliosphere encompass various processes, from the acceleration of solar wind electrons/ions to solar energetic particle events related to solar eruptive phenomena. Despite decades of research, several aspects of suprathermal and energetic particle production remain unknown, with the main candidate production mechanisms being magnetic reconnection, collisionless shocks and several categories of wave-particle interactions. How suprathermal and energetic particles are transported through the heliosphere is also object of active debate, and largely unconstrained. Recent missions, such as Solar Orbiter and Parker Solar Probe, have delivered excellent observations from the inner heliosphere, both remotely and in situ. When combined with data from missions like ACE, SOHO, Wind, and STEREO at 1 AU, these observations across varying radial distances offer an unprecedented opportunity to characterize the sources and transport mechanisms of suprathermal and energetic particles in the heliosphere.

This session invites contributions that explore space-borne and ground-based observations, as well as theoretical and modelling approaches, to deepen our understanding of the acceleration and transport of suprathermal and energetic particles in the heliosphere. We encourage submissions that provide new insights, propose innovative methodologies, or synthesize data across multiple missions to address these critical scientific challenges.

Coronal mass ejections (CMEs) can be listed amongst the most extreme manifestations of the Sun’s dynamic activity and are prominent drivers of space weather disturbances at Earth as well as other solar system bodies. Over the past few decades, remarkable advances through remote-sensing and in-situ measurements combined with analytical and MHD modeling have been made, but many fundamental questions remain regarding CME formation and eruption mechanisms, early coronal evolution, 3D interplanetary configuration, and interactions with the structured solar wind and other transients. As Solar Cycle 25 progresses beyond its maximum phase and towards the minimum, it is time to reassess our current understanding and identify promising directions for advancing CME observations, analysis, modeling, and forecasting capabilities.

This session encourages contributions that advance CME science across a wide range of approaches, taking advantage of the wealth of currently available observational data and models. We welcome presentations employing remote-sensing and/or in-situ observations, multi-spacecraft studies, modeling efforts focusing on CME eruption and/or propagation, and mission concepts that can significantly advance fundamental research while addressing remaining observational and knowledge gaps. Particular emphasis will be given to contributions employing novel theories, measurements, and techniques.

In 2017 the international multi-agency Next Generation Solar Physics Mission (NGSPM) Science Objectives Team published its final report, setting out the highest-priority science questions for solar physics in the coming decade and the measurements and instrumentation needed to answer them:

- How is the hot, dynamic outer solar atmosphere formed and sustained?
- What drives large-scale solar eruptions, and how can we predict them?
- What mechanisms govern the solar cycle and irradiance variability?

JAXA's multi-agency SOLAR-C and NASA’s Multi-slit Solar Explorer (MUSE) will soon launch to address these recommendations. SOLAR-C combines the EUV High-throughput Spectroscopic Telescope (EUVST), which will observe the solar atmosphere with unprecedented plasma diagnostic capability, with the Solar Spectral Irradiance Monitor (SoSpIM), which provides complementary full-Sun EUV spectral irradiance measurements. MUSE is a multi-slit spectrograph that will provide imaging spectroscopy of the corona at multiple wavelengths, up to 100 times faster than current instruments. The collective power of SOLAR-C and MUSE will transform our ability to probe the multi-scale physics of the corona, from small-scale energy release to its large-scale impacts.

Europe is central to delivering SOLAR-C. France is fabricating the EUV grating, Germany is contributing to calibration, testing and components, Italy is providing the slit, and Switzerland is building SoSpIM. The European Space Agency is providing the short-wavelength camera (which is being built in the UK).

This session invites observers, modellers and theoreticians to present current work and discuss future directions across solar physics to promote strong European science return from these missions. It also welcomes work highlighting the strong European contribution to SOLAR-C.

Space and astrophysical plasmas are typically in a turbulent state, exhibiting strong fluctuations of various quantities over a broad range of scales. These fluctuations are non-linearly coupled, and this coupling leads to the transfer of energy (and other quantities, such as cross helicity and magnetic helicity) from large to small scales and to dissipation. Turbulent processes are relevant for the heating of the solar wind and the corona, and the acceleration of energetic particles. In these environments, many aspects of turbulence are not well understood, in particular, the injection and onset of the cascade, the cascade itself, the dissipation mechanisms, as well as the role of coherent structures and waves. Specific phenomena such as magnetic reconnection, shock waves, solar wind expansion, plasma instabilities, wave activity and their relationship with the turbulent cascade and kinetic dissipation processes are under debate. The session will explore these open questions through observational, theoretical, numerical, and laboratory studies, aiming to advance our understanding of these processes.

For observational studies, we welcome contributions utilizing data from a wide range of relevant space missions, including single-spacecraft WIND, STEREO, Van Allen Probes, and DSCOVR, with particular emphasis on recent findings from Solar Orbiter and Parker Solar Probe, and multi-spacecraft Cluster, MMS, THEMIS. We also particularly welcome studies preparing for the science and analysis of the upcoming HelioSwarm and Plasma Observatory missions.

The "Theory and Simulation of Solar System Plasmas" session is a forum for presenting recent results related to theoretical and numerical investigation of heliospheric plasmas. Our regions of interest are the Sun and its corona, the solar wind and planetary magnetospheres. Processes of interest are magnetic reconnection, turbulence, shock waves, plasma instabilities, plasma heating and particle acceleration.

We welcome particularly studies integrating numerical modeling, theoretical investigations and in-situ measurements/ remote observations from current and future space missions (MMS, Parker Solar Probe, Solar Orbiter, Bepi Colombo, ASO-S, Aditya-L1, SMILE, HelioSwarm, SPO, Plasma Observatory...). This year we intend to focus in particular on demonstrating how spacecraft observations, numerical models and theory can be integrated for deeper understanding of the heliospheric environment. Example of this integration are data-driven simulations, validation of theory and simulations against observations, the several ways methods rooted in Machine Learning to the system can be applied to the heliospheric system, data assimilation.

Understanding how the solar wind is formed, accelerated, and transported through the heliosphere remains central to advancing both heliophysics and space weather forecasting. Measurements from recent missions such as Parker Solar Probe, Solar Orbiter, Proba-3, PUNCH and BepiColombo have been opening up new paths to unexplored regions of near-Sun space and provided unprecedented perspectives on solar wind variability. Looking ahead, upcoming observatories like ESA’s Vigil will further expand our capability to connect coronal drivers with in-situ measurements across the heliosphere, and to better predict their space weather impacts.
This session invites contributions that make use of theoretical advances, innovative modelling approaches, and multi-platform observations to probe the solar wind and to determine its properties from its source regions to its interactions with planetary environments. Topics of interest include the origins of the fast and slow solar wind, mechanisms of heating and acceleration, evolution of large-scale structures, fine-scale dynamics, and the role of magnetic connectivity. We particularly welcome studies that integrate data and models to bridge scales and regions, as well as perspectives that outline future priorities for solar wind research.

Cosmic rays provide an important probe of particle acceleration and transport processes throughout the heliosphere. They include solar energetic particles (SEPs), accelerated during solar eruptive events, and galactic cosmic rays (GCRs), which originate outside the heliosphere and are modulated by heliospheric conditions. Their variability reflects the complex interplay between energetic particles and solar and heliospheric activity across a wide range of spatial and temporal scales. This session will focus on the acceleration, transport, modulation, and variability of cosmic rays in the heliosphere, including, but not limited to, SEPs, Forbush decreases, anisotropic cosmic ray enhancements (ACREs), and longer-term variations in GCR fluxes. We invite contributions addressing observations, modelling, data analysis, and the phenomenology of cosmic rays in the heliosphere, as well as their connections to solar and heliospheric dynamics. We particularly encourage contributions that employ or combine multi-spacecraft and ground-based observations, numerical and theoretical models, novel data-analysis techniques, and forecasting approaches, as well as studies that connect measurements across different spatial and temporal scales and regions of the heliosphere.

Collisionless shocks are ubiquitous in the universe, occurring in diverse astrophysical environments, from planets to galaxy clusters. Significant efforts have been made to understand their rich dynamics and their effects on the surrounding environment, including particle thermalization and acceleration, turbulence generation, and the evolution of various transient phenomena.

Heliospheric shocks offer the unique advantage of being directly accessible by in situ measurements. Missions, such as Solar Orbiter, STEREO, and Parker Solar Probe, have deepened our knowledge of interplanetary shocks and the associated regions, while MMS, Cluster, THEMIS, Cassini, Maven, and others have similarly enhanced our knowledge of planetary bow shocks.

High-performance computing has also played a critical role in filling key knowledge gaps, enabling global and local simulations to provide insights into the nature of collisionless shocks.

Despite these efforts, many questions remain open. In particular, we still do not fully understand the mechanisms associated with certain aspects of particle heating and acceleration, wave generation, wave-particle interaction, and energy redistribution at shocks. The interplay of collisionless shocks and pre-existing plasma turbulence also remains poorly understood. Additionally, details about the formation and impact of transient structures, such as hot flow anomalies, foreshock bubbles, cavitons, spontaneous hot flow anomalies, magnetosheath jets, etc., are still unknown.

We thus welcome observational, numerical, and theoretical works that explore plasma processes at collisionless shocks and surrounding regions.

The total solar eclipses of 12 August 2026 and 2 August 2027 offer exceptional opportunities for heliophysics and planetary science. This session invites contributions presenting results from the 2026 eclipse, including coordinated ground-based and space-borne observations, modelling, and public outreach and engagement. In particular, results from a multi-site observing campaign coordinated by EGU, COSPAR and LUNEX will be presented.

The session will also address preparations for the 2 August 2027 eclipse, whose path of totality crosses southern Spain, North Africa and the Middle East, with a maximum duration of totality of more than six minutes. We welcome contributions on instrumentation, space-based observations, modelling and predictions, as well as citizen science and public engagement.

The solar wind is a highly structured and continuously evolving plasma environment spanning a broad range of spatial and temporal scales. Large-scale features originating at the Sun evolve during heliospheric propagation, interact with the ambient plasma and with one another, and coexist with smaller-scale magneto-plasma formations generated locally. Together they create a complex hierarchy extending from streams, transients, shocks, and interaction regions to flux ropes, current sheets, discontinuities, turbulent fluctuations, waves, and kinetic-scale phenomena.
This session addresses the cross-scale evolution of this hierarchy and its role in energy transfer and dissipation throughout the heliosphere. We welcome studies of Interplanetary Coronal Mass Ejections (ICMEs) and ICME sheaths, interplanetary shocks, stream and corotating interaction regions (SIRs/CIRs), magnetic flux ropes, current sheets of different origins and scales (including the heliospheric current sheet), discontinuities, and other coherent magneto-plasma structure. Particular emphasis will be placed on how these environments generate, enhance, or modify turbulence, magnetic reconnection, plasma instabilities, and particle acceleration, and on how the resulting processes influence subsequent plasma evolution. This session is organized within the activities of the SCOSTEP Working Group under the same title.

Radio waves are ubiquitous in the heliosphere. Sources range from thermal emission due to the quiet Sun, radio bursts emitted by accelerated electrons from transient solar eruptions, planetary magnetospheres, and spacecraft and extra-solar sources whose signals propagate through the heliosphere. Together, these radio emissions provide powerful diagnostics of the Sun and the heliospheric environment. This session is devoted to the fundamental processes underlying radio-wave generation and propagation, and the broad range of heliospheric diagnostics enabled by radio emissions from GHz to kHz, whether of solar or extra-solar origin. We welcome contributions on a range of radio-focused topics, including gyrosynchrotron emission from the solar atmosphere, excitation of Langmuir waves and the resulting radio-wave production, as well as radio-wave generation in laboratory plasmas. We also encourage contributions that exploit radio observations to diagnose solar and heliospheric conditions, including investigations of density turbulence, magnetic fields, particle acceleration regions, and radio-wave propagation effects. Contributions related to space-weather applications, studies that combine observations and simulations, advances in radio instrumentation, and multi-wavelength, multi-instrument, multi-vantage point investigations are particularly welcome.

The session solicits contributions that report on nonthermal solar and planetary radio emissions. Coordinated multi-point observations from ground radio telescopes (e.g., LOFAR, LOIS, LWA1, URAN-2, UTR-2) and spacecraft plasma/wave experiments (e.g., BepiColombo, Solar Orbiter, Parker Solar Probe, UVSQ-Sat, Inspire-Sat 7, Cassini, Cluster, Demeter, Galileo, Juno, Stereo, Ulysses and Wind) are especially encouraged. Presentations should focus on radiophysics techniques used and developed to investigate the remote magnetic field and the electron density in solar system regions, like the solar corona, the interplanetary medium and the magnetized auroral regions. Interest also extends to laboratory and experimental studies devoted to the comprehension of the generation mechanisms (e.g., cyclotron maser instability) and the acceleration processes (e.g., Alfven waves). Further preparations, evaluations, investigations, analyses of forthcoming space missions or nanosatellites (like Juice, SunRISE, UVSQ-Sat NG…) are also welcome.

This session focuses on the non-linear processes taking place in space, laboratory, and astrophysical plasmas. In many cases, these processes appear deeply linked. For instance, magnetic reconnection is an established ingredient of the turbulence cascade, and it is also responsible for the production of turbulence in reconnection outflows and for the onset of a number of instabilities especially at the depolarization fronts. Turbulent dynamos are expected to play a role in the generation and growth of magnetic fields in a number of astrophysical and heliospheric settings. Shocks can result in turbulence formation, for example, in the turbulent magnetosheath, and can be efficient particle accelerators.

The study of these processes has seen significant progress in recent years thanks to a synergistic approach based on simulations and observations. On the one hand, simulations can deliver output on a range of temporal and spatial range of scales, going from fluid to electron kinetic scales. This is partly also due to the advent of GPU facilities, which have significantly increased the capability of numerical simulations in plasma physics. On the other hand, high cadence spacecraft measurements of particles and fields and high-resolution 3D measurements of particle distribution functions are currently provided by missions such as MMS, Parker Solar Probe, and Solar Orbiter. These missions are opening new research scenarios in heliophysics and providing a consistent amount of new data to be analysed. Furthermore, other present and future missions that will give unique plasma measurements around solar system magnetospheres, such as Bepi Colombo, Juice, Comet Interceptor, Plasma Observatory and HelioSwarm, are demanding the development of new numerical tools for successful interpretation of the observations.

This session welcomes simulation, observational, and theoretical contributions relevant to studying the above-mentioned processes. We also encourage papers proposing new methods in simulation techniques and data analysis, for example, those rooted in Artificial Intelligence or those based on multi-point satellite observations.

Energetic solar eruptions encompass a range of interconnected phenomena, including fast coronal mass ejections (CMEs), strong X-ray flares, large solar energetic particle (SEP) events, and the coronal waves and shocks associated with them. Understanding how these phenomena are related, how energy is partitioned between them, and how they contribute to the acceleration and release of energetic particles remains an open question in solar and heliospheric physics. The respective roles of flares, CMEs and CME-driven shocks in particle acceleration and release, as well as the role of magnetic connectivity, are still being investigated. The propagation of CMEs, shocks and magnetic structures through the heliosphere can also affect galactic cosmic rays (GCRs), producing Forbush decreases (FDs) that provide information on the evolution and large-scale structure of interplanetary disturbances.
The expanding fleet of heliospheric spacecraft, together with remote-sensing and ground-based observations, allows these processes to be studied over a wide range of heliocentric distances. Observations from Solar Orbiter, Parker Solar Probe, STEREO-A, BepiColombo and near-Earth spacecraft can be combined with observations of the solar corona, radio measurements and ground-based cosmic-ray data. This makes it possible to study the evolution of solar eruptions, their magnetic connections, particle acceleration and transport, and the modulation of GCRs from the Sun to interplanetary space. Projects such as SPEARHEAD and SOLER have contributed to this effort through coordinated datasets, catalogues, analysis tools and modelling approaches for energetic solar eruptions and energetic particles.
This session invites observational, theoretical and modelling studies of energetic solar eruptions and their interrelations, from the solar corona to interplanetary space. Contributions on flares, CMEs, coronal waves and shocks, SEP acceleration and release, magnetic connectivity and particle transport are welcome, as are studies of Forbush decreases and the modulation of GCRs by CMEs, ICMEs and magnetic structures. We also welcome presentations on new data products, analysis methods and tools for studying energetic solar eruptions and their heliospheric consequences.

Cosmic rays carry information about space and solar activity, and, once near the Earth, they produce isotopes, influence genetic information, and are extraordinarily sensitive to water. Given the vast spectrum of interactions of cosmic rays with matter in different parts of the Earth and other planets, cosmic-ray research ranges from studies of the solar system to the history of the Earth, and from health and security issues to hydrology, agriculture, and climate change. Although research on cosmic-ray particles is connected to a variety of disciplines and applications, they all share similar questions and challenges regarding the physics of detection, modelling, and the influence of environmental factors.
The session brings together scientists from all fields related to monitoring and modelling cosmogenic radiation. It will allow the sharing of expertise amongst international researchers as well as showcase recent advancements in their field. The session aims to stimulate discussions about how individual disciplines can share their knowledge and benefit from each other.
We solicit contributions related but not limited to:
- Health, security, and radiation protection: cosmic-ray dosimetry on Earth and its dependence on environmental and atmospheric factors
- Planetary space science: satellite and ground-based neutron and gamma-ray sensors to detect water and soil constituents
- Neutron and Muon monitors: detection of high-energy cosmic-ray variations and its dependence on local, atmospheric, and magnetospheric factors
- Hydrology and climate change: low-energy neutron sensing to measure water in reservoirs at and near the land surface, such as soil, snowpack, and vegetation
- Cosmogenic nuclides: as tracers of atmospheric circulation and mixing; as a tool in archaeology or glaciology for dating of ice and measuring ablation rates; and as a tool for surface exposure dating and measuring rates of surficial geological processes
- Detector design: technological advancements in the detection of cosmic rays and cosmogenic particles
- Cosmic-ray modelling: advances in modelling of the cosmic-ray propagation through the magnetosphere and atmosphere, and their response to the Earth's surface
- Impact modelling: How can cosmic-ray monitoring support environmental models, weather and climate forecasting, agricultural and irrigation management, and the assessment of natural hazards

This open session traditionally invites presentations on all aspects of the Earth’s magnetospheric physics, including the magnetosphere and its boundary layers, magnetosheath, bow shock and foreshock as well as solar wind-magnetosphere-ionosphere coupling. We welcome contributions on various aspects of magnetospheric observations, remote sensing of the magnetosphere’s processes, modelling and theoretical research. Presentations related to current and planned space missions, as well as value-added data services, are also encouraged. Additionally, we welcome comparative studies of processes in the magnetospheres of Earth and other planets. This session is particularly suitable for any contribution which does not fit more naturally into one of the specialised sessions and for contributions of wide scientific interest.

The joint European Space Agency/Chinese Academy of Sciences (ESA/CAS) Solar Wind Magnetosphere Ionosphere Link Explorer (SMILE) mission was successfully launched from Kourou, French Guiana, on 19 May 2026. SMILE is a novel mission, directly imaging the Sun-Earth interaction. In particular, SMILE images the magnetosheath/magnetopause and cusp regions using a novel soft X-ray instrument, complemented by a UV instrument that is imaging the Northern auroral oval for more than 40 hours continuously. In addition, the solar wind and magnetospheric plasma in the vicinity of the spacecraft is simultaneously measured by a magnetometer and an ion instrument. After reaching its science orbit of 1.7 x 19 RE (geocentric distance) inclined at 70 deg and completing commissioning activities, the nominal mission began in September 2026.  In this session, the first results from the mission will be presented along with information for the community on how to access the SMILE data systems. We encourage presentations on complementary measurements from other missions and ground-based facilities and modelling results in support of the SMILE mission goals.

Understanding plasma energisation and energy transport is a grand challenge of space plasma physics. Due to its proximity, the Earth’s Magnetospheric System provides an excellent natural laboratory for the investigation of these phenomena. Fundamental processes such as collisionless shocks, magnetic reconnection, turbulence, wave-particle interactions, plasma jet braking, and their combination initiate and govern particle energisation and energy transport. These processes occur in key magnetospheric regions including the foreshock, the bow shock, the magnetosheath, the magnetopause, the magnetotail current sheet, and the transition region.
ESA/Cluster and NASA/MMS four-point constellations, as well as the large-scale multipoint mission NASA/THEMIS, have greatly improved our understanding of these plasma processes at individual scales compared to earlier single-point measurements. However, these missions have also revealed that such processes inherently operate across multiple scales, ranging from large fluid scales to smaller kinetic scales, demonstrating the need for multi-scale in situ observations. In particular, simultaneous measurements at fluid and kinetic scales are required to resolve how energy is transferred between scales and ultimately converted into particle energisation and transported throughout the plasma system.
Building on previous single-scale missions, the Plasma Observatory (PO) mission represents the next generation of space plasma physics investigations. PO is a seven-spacecraft multi-scale mission, tailored to study plasma energisation and energy transport in the Earth’s Magnetospheric System simultaneously at both fluid and ion scales. Plasma Observatory has been recommended by the ESA science advisory committees for selection as the M7 mission in the ESA Science Programme.
This session invites submissions on multi-scale and cross-scale coupling, including simulations, multi-point techniques, instrumentation, and theory. Submissions addressing connections between in situ measurements, remote sensing, and ground-based observations are also strongly encouraged.

Magnetic reconnection is a key process in space, astrophysical, and laboratory plasmas that explosively converts magnetic energy into kinetic energy of charged particles. Thanks to recent spacecraft missions (e.g., MMS, Cluster, THEMIS, Parker Solar Probe, etc.) and the development of numerical simulations, many new findings have been achieved in the last several years. Also, many important issues remain: the triggering mechanisms, quantitative aspects of the energy conversions, identification of the electron diffusion/dissipation region, coupling across multiple scales, and so on. This session invites presentations on all of the aspects associated with magnetic reconnection from the spacecraft measurements, theoretical analysis, numerical simulations, and laboratory experiments.

Kelvin-Helmholtz Instability (KHI) is a fundamental plasma process driven by velocity shears, being ubiquitous in both fluids and plasmas. It has been observed in the magnetospheres of planets with (e.g. Earth, Mercury, Jupiter, Saturn) and without a magnetic field (e.g. Mars, Venus), as well as in the solar corona and solar wind at the boundary of coronal mass ejections. Contrary to neutral fluids, which are always unstable to KHI, in a magnetized environment, the magnetic field plays a crucial role acting as a stabilizer. As a driver of large-scale vortices along the boundary, KHI contributes to mass and momentum transport, enabling plasma mixing that would otherwise be limited in a highly magnetized environment. Moreover, as the instability grows, vortices become increasingly steepened and rolled-up. The nonlinear interaction of modes produces an energy cascade from the large-scale vortices to kinetic scales, where dissipation mechanisms such as wave-particle interactions and reconnection heat the plasma. The nonlinear evolution of KHI-generated vortices can trigger secondary processes or waves, such as Rayleigh-Taylor instability, lower hybrid waves, and generate thin current sheets where magnetic reconnection can occur, as well as develop a turbulent environment.

Solar wind and the interplanetary magnetic field (IMF) power and drive the dynamics in the geospace and planetary magnetospheres and ionospheres in the solar system. Characteristics of the processes involved in the solar wind-magnetosphere-ionosphere coupling are essential to be studied to better understand how mass, momentum and energy are transferred between these regions. The consequences of the coupling are also vital to be investigated to fully understand all phenomena that are controlled by the solar wind conditions, such as the magnetosphere configuration, plasma convection, electric currents, ULF waves and ring current/radiation belt dynamics. This session welcomes presentations on recent advances in the solar wind-magnetosphere and/or ionosphere coupling within Earth and planetary space environments. Also, presentations connecting various ionospheric and auroral phenomena with their magnetospheric counterparts/solar wind drivers and exploring coupling mechanisms are invited. Studies discussing space-based and/or ground-based observations as well as theoretical and/or modelling perspectives are highly encouraged.

Collisionless space plasmas present a unique physical environment where charged particles interact not through direct collisions but through electromagnetic waves, making wave-particle interactions a cornerstone of space plasma physics. These interactions shape the spectral properties of plasma waves, regulate particle energisation and loss across a wide range of energies, and drive the evolution of particle distribution functions far from thermal equilibrium. Alongside these processes, a rich variety of kinetic phenomena add further complexity, including current sheet dynamics, nonlinear wave structures such as phase space holes and solitary waves, wave-mode conversion, and non-resonant wave-particle interaction. Together, these processes operate across electron and ion scales, connecting microscale plasma physics to the macroscale evolution of space plasma systems, and challenging traditional frameworks such as quasilinear diffusion theory.

A growing fleet of spacecraft, including historical missions like Van Allen Probes, Cluster, Cassini and ongoing missions like MMS, Arase, THEMIS, MAVEN, Juno, Parker Solar Probe, Solar Orbiter, along with CubeSat platforms like ELFIN, FY, CIRBE, REAL, LLITED provide multi-point, high-resolution observations that reveal both common physical mechanisms and intriguing differences across the solar wind, radiation belts, and planetary magnetospheres. These datasets, combined with increasingly sophisticated simulation and modelling tools, are opening new avenues for advancing our understanding of kinetic plasma processes across diverse space environments.

This session welcomes contributions from theorists, observationalists, and modellers working across all aspects of wave-particle interactions and kinetic physics in collisionless space plasmas.

Earth's inner magnetosphere contains diverse charged-particle populations, including the Van Allen radiation belts, ring current, and plasmasphere, spanning energies from eV to several MeV. These populations are dynamically coupled through various processes that produce feedback across different plasma regimes. Ring current particles can generate waves, including EMIC and chorus waves, which in turn influence radiation belt dynamics through wave-particle interactions. Ring current electrons can be accelerated to relativistic energies and contribute to the radiation belts, while the plasmaspheric environment can regulate wave generation, propagation, and particle scattering. Coupling also extends beyond the inner magnetosphere. Precipitation of ring current and radiation belt particles modifies the ionosphere and upper atmosphere, while ionospheric outflows can influence magnetospheric plasma populations and dynamics. Understanding such interactions is essential both for advancing fundamental knowledge of magnetospheric dynamics and for improving space weather specification and forecasting. Beyond Earth, the magnetospheres of the outer planets are driven by different combinations of internal and external processes, yet they exhibit many analogous forms of plasma transport, acceleration, loss, and coupling. Comparative studies therefore provide valuable opportunities to identify common physical mechanisms as well as processes unique to individual planetary environments.
We invite theoretical, modelling, and observational studies addressing the dynamics and coupling of Earth's and other planetary inner magnetospheres. Relevant topics include interactions among radiation belt, ring current, and plasmaspheric populations; wave particle interactions; magnetosphere-ionosphere coupling; particle precipitation and ionospheric outflow; responses to solar wind disturbances; and comparative magnetospheric physics. Contributions using numerical simulations, satellite and ground-based observations, data assimilation approaches, and new mission concepts are welcome. We particularly encourage studies using observations from missions and facilities such as MMS, THEMIS, Van Allen Probes, Arase (ERG), Cluster, CubeSats, Juno, SuperDARN, magnetometers, optical imagers, incoherent-scatter radars, and ground-based VLF measurements.

Planetary magnetospheres across the Solar System offer an exceptional opportunity to study universal plasma processes operating under fundamentally different magnetic, atmospheric, rotational and solar-wind conditions. Comparative investigations allow us to distinguish physical mechanisms that are common across planetary environments from those that are unique to individual systems, thereby advancing both fundamental plasma physics and planetary space weather.

Recent and ongoing missions, including BepiColombo, JUICE, Juno, Cassini, Arase, Cluster, MMS, THEMIS, Van Allen Probes, SMILE and complementary ground-based observations, together with advances in first-principles modelling, global simulations, data assimilation, machine learning and artificial intelligence are enabling a new era of comparative magnetospheric science.

We welcome observational, theoretical and modelling studies of planetary magnetospheres, including but not limited to:
• Particle acceleration, transport and loss
• Wave–particle interactions and plasma waves
• Radiation belts and energetic particle populations
• Magnetic reconnection and global plasma circulation
• Magnetosphere–ionosphere–atmosphere coupling
• Auroral processes and energetic particle precipitation
• Solar-wind-driven and internally driven magnetospheric dynamics
• Comparative studies of Mercury, Earth, Jupiter, Saturn, Uranus, Neptune, Mars, Venus and exoplanetary environments
• Numerical modelling, data assimilation, digital twins and machine learning
• Multi-mission analyses and future planetary exploration missions
We especially encourage contributions that bridge planetary science and solar-terrestrial physics, compare multiple planetary environments, or combine observations, theory and advanced data-driven methods. The session aims to strengthen interactions between the PS and ST communities, identify universal plasma processes across planetary magnetospheres, and stimulate new international collaborations and future mission concepts.

Jupiter’s icy moons are prime targets for understanding the potential for habitable environments beyond Earth. Europa Clipper and Jupiter Icy Moons Explorer are designed to address these questions, with arrivals in the Jovian system in April 2030 and July 2031, respectively. This session invites contributions aligned with these missions’ objectives, including investigations of surface properties, internal structures, subsurface ocean dynamics, and implications for habitability. We also welcome studies of interactions with Jupiter’s space environment and long-term evolution within the Jovian system. Abstracts on cruise-phase science are also encouraged, including gravity-assist observations, studies of 3I/ATLAS, and heliophysics investigations. As we enter an era of dual-spacecraft exploration, this session will highlight complementary capabilities and the synergistic science enabled by combined observations.

In recent years, technologies based on Artificial Intelligence (AI), such as image processing, smart sensors, and intelligent inversion, have garnered significant attention from researchers in the geosciences community. These technologies offer the promise of transitioning geosciences from qualitative to quantitative analysis, unlocking new insights and capabilities previously thought unattainable.
One of the key reasons for the growing popularity of AI in geosciences is its unparalleled ability to efficiently analyze vast datasets within remarkably short timeframes. This capability empowers scientists and researchers to tackle some of the most intricate and challenging issues in fields like Geophysics, Seismology, Hydrology, Planetary Science, Remote Sensing, and Disaster Risk Reduction.
As we stand on the cusp of a new era in geosciences, the integration of artificial intelligence promises to deliver more accurate estimations, efficient predictions, and innovative solutions. By leveraging algorithms and machine learning, AI empowers geoscientists to uncover intricate patterns and relationships within complex data sources, ultimately advancing our understanding of the Earth's dynamic systems. In essence, artificial intelligence has become an indispensable tool in the pursuit of quantitative precision and deeper insights in the fascinating world of geosciences.
For this reason, aim of this session is to explore new advances and approaches of AI in Geosciences.

The importance of ionospheric research is increasing alongside the development of modern terrestrial and space-based technologies, given that the ionosphere reflects and modifies the radio waves used for communication and navigation. Understanding coupling processes is crucial to understanding ionospheric dynamics and variability. The ionosphere is influenced by various solar and magnetospheric processes from above. The strongest of these are well-developed magnetic storms. These are both ICME- and CIR/HSS-related. However, many other drivers remain poorly understood. Conversely, the ionosphere is primarily forced from below by atmospheric waves, such as planetary, tidal, and acoustic-gravity waves. This symposium invites observational, simulation and modelling studies addressing ionospheric dynamics, with a particular focus on magnetospheric and lower atmospheric forcing and the associated feedback on ionospheric variability.
We particularly welcome new results focusing on the latitudinal, seasonal and hemispherical effects of magnetic storms and substorms on the ionosphere. Regarding atmospheric forcing, contributions focusing on atmospheric waves, wave-wave interactions, wave-mean flow interactions, atmospheric electricity and electrodynamic coupling processes are sought. Contributions examining ionospheric effects caused by other phenomena, such as the solar terminator, solar eclipses, seismic activity, or human-made explosions, are also welcome. This session invites contributions on the use of AI as a tool for searching for, processing and analysing ionospheric measurements, as well as for validating and refining ionospheric models. Therefore, knowledge of how to use AI as a tool in ionosphere research is highly desirable.

The high-latitude ionosphere is a highly dynamic environment shaped by solar and magnetospheric forcing, atmospheric dynamics, and plasma transport across a wide range of spatial and temporal scales. Understanding these processes requires coordinated observations and modelling, supported by complementary techniques including incoherent scatter radars, GNSS networks, magnetometers, optical instruments, satellites, and other remote-sensing systems.

This session brings together observational and modelling studies that use multiple techniques to investigate high-latitude ionospheric variability, plasma structuring and transport, auroral processes, and atmosphere-ionosphere-magnetosphere coupling. We particularly encourage contributions addressing multi-instrument observations, observation-model comparisons, cross-validation, data integration, and challenges associated with observing and modelling processes across different spatial and temporal scales.

The session will also provide a forum to discuss the coordination of high-latitude observations, development of integrated observational and modelling approaches, and opportunities for collaborative campaigns and shared strategies in preparation for the 5th International Polar Year (2032-2033).

The equatorial and low-latitude ionosphere is a region of profound ionospheric activity and variability, presenting significant challenges for both scientific understanding and operational prediction. Its strong day-to-day (DTD) variability, and its direct impact on the occurrence of plasma irregularities and associated ionospheric scintillations, remains a critical and highly challenging subject in space weather research.

A key obstacle to progress has been the inherent difficulty in obtaining simultaneous, comprehensive observations of the coupled ionosphere-thermosphere system. To truly characterize the sources of DTD variability and determine their relative importance, an integrated, multi-disciplinary approach is essential.

This session invites contributions that explore new and integrated pathways to address these challenges. We are particularly interested in:

· New Observations: Novel ground-based and space-based observational techniques and networks that provide critical data on the equatorial and low-latitude ionosphere-thermosphere system.
· Advanced Modeling: Physics-based and first-principles modeling efforts that seek to simulate and understand the sources of DTD variability and their nonlinear interactions.
· Data-Driven Approaches: Innovative applications of machine learning, data assimilation, and other data-driven techniques to fuse disparate data sets, uncover complex patterns, and improve forecasting capabilities.

The ultimate goal of this session is to foster a dialogue that bridges observation, theory, and application, with a focus on improving the predictability of the equatorial and low-latitude ionosphere and its irregularities across a wide range of solar, geomagnetic, and lower atmospheric conditions.

The lower thermosphere-ionosphere (LTI) system is the transition region between Earth’s atmosphere and space. It is characterized by large changes in the dynamics, energetics, composition, and ionization of the atmosphere. In this region, the atmosphere transitions from a well-mixed to a diffusively separated state, and the atmosphere becomes increasingly ionized. Meanwhile, the electrodynamic wind dynamo couples different regions across latitudes and altitudes.
The spatial-temporal morphology of the LTI is influenced by forcing from the lower atmosphere and solar and geomagnetic activity. Their interplay leads to complex regional and global variability on timescales from hours to months, creating a challenge for understanding the LTI behavior. Although a basic understanding of the connection between the lower and upper atmosphere via waves and global circulation changes has been achieved, we still have a limited understanding of the LTI structure itself, e.g., spatial-temporal structure and variability of neutral and plasma density, composition, temperature, and wind, as well as the processes determining them, and their relative importance.
This limited understanding is partly due to the fact that we lack continuous and high-resolution observations in the LTI region. Consequently, LTI processes were often investigated indirectly with data taken remotely from ground or at Low-Earth-Orbit (LEO) altitudes (> 300 km). However, Very LEO (VLEO) altitudes (< 300 km) are increasingly becoming important for modern space-based infrastructure, and therefore there is a growing need to better understand the variability of the VLEO environment and the processes controlling the region, including but not limited to neutral and plasma composition, wind, and temperature, and electrodynamics.
This session invites presentations that define the critical environmental knowledge needs at VLEO altitudes. We equally solicit studies that quantify LTI structure, variability, and driving processes using numerical, statistical and machine learning models and current observations, including uncertainty quantification, as well as new observing techniques or proposed mission concepts.

The Earth's middle atmosphere, mesosphere, and lower thermosphere (MLT) region provide a great platform for studying ionospheric dynamics, disturbances, eddy mixing, atmospheric drag effects, and space debris tracking. The thermal structure of these regions is influenced by numerous energy sources such as solar radiation, chemical, and dynamical processes, as well as forces from both above (e.g., solar and magnetospheric inputs) and below (e.g., gravity waves and atmospheric tides). Solar atmospheric tides, related to global-scale variations of temperature, density, pressure, and wind waves, are responsible for coupling the lower and upper layers of the atmosphere and significantly impact their vertical profiles in the upper atmosphere. With evidence of climate change impacts on the middle and upper atmosphere, monitoring and understanding trends through observational data is critical. There has been a contraction of the stratosphere and a decrease in the density of the upper atmosphere, which could impact the accumulation of space debris. This session invites presentations on scientific work related to various experimental/observational techniques, numerical and empirical modeling, and theoretical analyses on the dynamics, chemistry, and coupling processes in the altitude range of ~ 20 km to 180 km of the middle atmosphere and MLT regions, including long-term climatic changes.

Assessing the time-dependent probability of earthquakes and anticipating their cascading effects—including earthquake-generated tsunami waves and volcanic unrest—remain major challenges in Earth sciences. Recent advances in ground-based and spaceborne observations, laboratory experiments, numerical modelling, statistical analysis, computational methods and data-driven approaches offer unprecedented opportunities to investigate preparatory processes and evolving hazards by integrating heterogeneous observations across the different domains of the Earth system.
The session aims to foster interdisciplinary discussion on earthquake-related processes and to assess critically how multiparametric observations, physical knowledge and advanced data-analysis methods can improve our understanding, forecasting and time-dependent assessment of seismic and volcanic hazards and their impacts.
Particularly welcome are studies addressing:
- Ground-based and satellite observations of electric, magnetic, electromagnetic anomalies potentially associated with impending seismic and volcanic activity;
- Multi-parametric seismological, geodetic, geological, geochemical, hydrological, atmospheric and ionospheric observations;
- Lithosphere Atmosphere Ionosphere Coupling (LAIC) and related measurements;
- Transient deformation, fluid-related processes, seismicity patterns, earthquake-generated tsunami waves and other coupled phenomena;
- Possible relationships between seismic processes, Earth tides, lunar forcing, solar–Earth interactions and Space Weather;
- Theoretical models, numerical simulations and long-term data-analyses;
- Artificial intelligence, machine learning and deep-learning methods for anomaly detection, data integration, forecasting and uncertainty assessment.
Contributions presenting results from new instruments, innovative observational infrastructures and current or forthcoming satellite missions investigating atmospheric, ionospheric and electromagnetic disturbances potentially related to seismic and volcanic activity are especially encouraged.
Further contributions may focus on real-time monitoring, multimission and multiplatform data integration, open-data services and interoperable platforms supporting the development of integrated Earthquake Observing Systems.

Time series are a common type of data generated by observational and modelling efforts across Earth, environmental and space sciences. Long-term observations are particularly important for understanding gradual changes and assessing risks, yet are often difficult to sustain and fund. Their characteristics can vary substantially, from short to long records, linear to nonlinear dynamics, univariate to multivariate data, and single- to multi-scale variability. These differences call for both tailored methodologies and general approaches.

A key challenge is distinguishing random fluctuations from long-term changes in order to better understand processes within and across Earth system components. This requires knowledge of temporal variability and, often, sufficiently long observations. For example, reliable sea-level trends may require several decades of continuous measurements because of decadal variability. Likewise, the stochastic variability of geophysical time series can exhibit power-law scaling, requiring long records for robust statistical assessment.

Time series analysis encompasses a broad range of tasks, including:
- characterizing nonlinear variability in the time and/or frequency domain;
- quantifying complexity, predictability and scaling properties;
- identifying statistical interdependencies within and between time series;
- distinguishing co-variability from causal relationships;
- reducing dimensionality and identifying meaningful modes of variability; and
- developing stochastic and deterministic statistical or dynamical models.

This session invites contributions on the development and application of modern methods for analysing observational and model time series across the EGU community, including geophysical, geodynamic, oceanographic, geodetic and climate observations from terrestrial observatories and remote sensing. Contributions addressing advances in sensors, instrumentation, monitoring, analysis and interpretation, as well as comparisons of different approaches, are welcome. Studies using novel methods, including AI, for the analysis of long time series are particularly encouraged. We aim to foster interdisciplinary exchange and cross-fertilization between different EGU divisions.

This open session investigates the complex interplay within the Sun–Earth system, focusing on the dynamic processes that drive space weather and climate. Topics include the progression from solar phenomena, including flares, coronal mass ejections, and the solar wind, to their subsequent interactions with Earth’s magnetosphere, ionosphere, and thermosphere. The session also assesses the cascading risks to critical infrastructure, specifically satellite operations, navigation and communication networks, power grids, and aviation. By bridging observational data, theoretical modeling, and operational insights, this session highlights the necessity of understanding both acute space weather events and the long-term implications of solar variability for our increasingly technological society.

The Sun-Earth system changes on timescales from decades
to millennia. Solar activity has declined from the twentieth-century
Grand Maximum, geomagnetic activity has followed with its own lag and
response, and the coupled magnetosphere-ionosphere-thermosphere
system responds to these drivers while also undergoing anthropogenic
change from increasing greenhouse gases and ozone recovery.
Disentangling these trends and their interactions is essential for
understanding the long-term behaviour of the heliosphere and for
interpreting historical, proxy, and instrumental records.

This session brings together the communities studying long-term change
across all sub-systems of Sun-to-planet interactions. We invite
contributions on: secular variability of solar activity, irradiance
and magnetic field, including proxy reconstructions and the
solar-stellar connection; the long-term evolution of the solar wind,
heliospheric magnetic field, and cosmic-ray modulation; centennial
trends in geomagnetic activity and solar-terrestrial coupling; trends
in the ionosphere, thermosphere and mesosphere and their separation
into solar, geomagnetic, and anthropogenic components; and the
multi-cycle response of planetary upper atmospheres and ionospheres,
notably at Mars and Venus, as revealed by long-lived orbiter missions.
Observational, proxy-based, and modelling studies are welcome, as are
contributions on data homogeneity and trend-detection methodology.
Contributions from international working groups and programmes addressing long-term trends in solar-terrestrial relations (e.g. SCOSTEP, IAU, ISSI) are particularly welcome.

This session discusses plasma processes at and around the Moon, from kinetic scales such as plasma-surface interactions and mini-magnetospheres to the global-scale Earth-Moon magnetospheric system. We invite contributions on space plasma processes occurring at and around the Moon, including the lunar wake, mini-magnetospheres, plasma-surface interactions, surface charging, plasma-exosphere-dust-regolith coupling, energetic particle environment, and space weather at the Moon. Studies using the Moon as an observing platform for terrestrial magnetospheric and heliospheric processes, as well as for space weather monitoring, are equally welcome. Comparative studies of plasma processes at the Moon and at Earth, Mercury, Mars, Venus, asteroids, Phobos, Deimos, and outer planetary moons are also encouraged. We welcome contributions based on data analysis, theoretical studies, numerical simulations, new methodology, laboratory experiments, space instrumentation, future mission concepts, and combinations thereof.

Space weather and space climate encompass the dynamic interactions between the Sun and Earth, occurring across timescales from minutes to decades. These interactions involve processes occurring at the Sun, in the heliosphere, magnetosphere, ionosphere, thermosphere, and lower atmosphere. Key drivers include coronal mass ejections (CMEs), interplanetary shocks, and solar energetic particle (SEP) events. Predicting extreme space weather events and developing mitigation strategies is essential because space assets and critical infrastructures, such as satellite systems, communication and navigation networks, power grids, and aviation operations, are highly sensitive to the space environment. Conducting post-event analyses is crucial for improving and maintaining numerical models that can predict extreme space weather events and prevent the failure of critical infrastructures.

This session focuses on the current state of space weather products and explores new ideas and developments that can improve our understanding of space weather and space climate and their impact on critical infrastructure. We invite contributions on topics including, but not limited to: forecasting and nowcasting tools and services; satellite observations and data assimilation techniques; numerical model development, validation, and verification; machine learning applications in space weather prediction; generation and refinement of solar, geomagnetic, and ionospheric indices. We particularly welcome interdisciplinary and collaborative approaches that bridge research and operational communities. Contributions that address the drivers and the real-world impacts of space weather on systems such as aviation, pipelines, power distribution, human spaceflight, and auroral tourism are strongly encouraged.

The ionospheres and (induced) magnetospheres of unmagnetized and weakly magnetized bodies with (substantial) atmospheres (e.g. Mars, Venus, Titan, Pluto and comets) are subject to disturbances due to solar activity, interplanetary conditions (e.g. solar flares, coronal mass ejections and solar energetic particles), or for moons, parent magnetospheric activity. These objects interact similarly as their magnetized counterparts but with scientifically important differences.
As an integral part of planetary atmospheres, ionospheres are tightly coupled with the neutral atmosphere, exosphere and surrounding plasma environment, possessing rich compositional, density, and temperature structures. The interaction among neutral and charged components affects atmospheric loss, neutral winds, photochemistry, and energy balance within ionospheres.
This session invites abstracts concerning remote and in-situ data analysis, modelling studies, comparative studies, instrumentation and mission concepts for unmagnetized and weakly magnetized solar system bodies.

Satellite data and geomagnetic observatories give us a detailed picture of the modern geomagnetic field and the Sun–Earth system. To look further back, we can turn to geological archives, offshore cores, stratigraphic sequences, cosmogenic radionuclide records (e.g., ¹⁰Be), and geo/paleomagnetic reconstructions. Together, these records allow us to investigate how the Earth’s magnetic field, environmental conditions, and solar activity have changed over centuries, millennia, and longer geological timescales, and to explore the links between them. This long-term perspective is essential for understanding the modern Earth–Sun system, in which the geomagnetic field connects processes ranging from the Earth’s deep interior to the atmosphere and near-Earth space. It also often requires combining magnetic information with other proxies, models, and observations across different timescales. This combination can bring additional benefits, for example, helping to tackle the dating uncertainties that many paleo-sciences face.

This session welcomes studies linking geomagnetism, paleomagnetism, rock and environmental magnetism with solar variability (irradiance), cosmogenic radionuclides, paleoclimate proxies, space climate and other fields. We particularly encourage contributions that combine different geophysical and geological records, proxies, methods or timescales, including links with paleoclimate records, modelling, and modern ground-based and satellite observations. The session aims to bring these communities together and explore the links between geomagnetic, solar and Earth-system variability across different timescales.