This session encompasses the full spectrum, from the geomagnetic field (polarity transition-reversals and excursions) and upper atmosphere to the magnetosphere, interplanetary space, and solar atmosphere. This special topic showcases the latest research advancements through a multidisciplinary approach, integrating geoscience, planetary science, solar physics, space physics, atmospheric science, and computing science, highlighting their cutting-edge discoveries. We particularly encourage integrative contributions that involve observations, measurements, and models to enhance our understanding of the timing, duration, asymmetry, and spatial-temporal structure of polarity transitions and solar energetic particle-induced space weather disasters.
Conference topics:
1. Geomagnetic polarity transitions—reversals and excursions—from the physics of the geodynamo to constraints preserved in geological and archaeological archives and the time scales that link them.
2. Upper atmosphere magnetic field and associated fields
3. Magnetosphere, interplanetary magnetic field, and electromagnetic environment
4. The impact of solar atmospheric activity on the electromagnetic environment
5. Observations and measurement of magnetic fields and related topics
6. Modelling or measurements of space weather impacts on grounded systems (e.g. GICs)
Orals: Tue, 5 May, 16:15–18:00 | Room -2.20
Solar Cycle 25 has exceeded initial intensity predictions, characterized by a series of severe geomagnetic disturbances that have expanded the auroral oval well into mid-latitudes. This study presents a comparative analysis of the magnetospheric and ionospheric responses to three distinct events observed over the European sector, including regions such as Türkiye: the geomagnetic storms of November 2023, May 2024, and October 2024. By integrating Global Navigation Satellite System (GNSS)–derived Total Electron Content (TEC) data with ground-based magnetometer observations, the spatiotemporal evolution of these disturbances is characterized. All three events were driven by Coronal Mass Ejections (CMEs), yet their impacts on the mid-latitude ionosphere differed substantially. The May 2024 extreme storm was marked by prolonged negative ionospheric phases and severe TEC depletions over Europe, including Türkiye, primarily linked to compositional changes and disturbance dynamo electric fields (DDEFs). In contrast, the November 2023 storm exhibited coherent magnetic field depressions and rapid recovery phases, indicating a dominant role of prompt penetration electric fields (PPEFs). This comparative framework is extended to the October 2024 storm. Moreover, analysis of the vertical (Z) and horizontal (H) geomagnetic field components recorded at European observatories provides insight into the penetration of high-latitude current systems into lower latitudes during intense space weather events. The results demonstrate that mid-latitude regions experience complex electrodynamic coupling during the solar cycle maximum, governed by multiple mechanisms ranging from prompt electric field penetration to thermospheric heating across the Eastern Mediterranean sector.
How to cite: Çiftçi, E., Hacıoğlu, Ö., and Kotan, B.: Auroral Signatures of Solar Cycle 25 at Mid-Latitudes: A Comparative Analysis of the November 2023, May 2024, and October 2024 Geomagnetic Storms, EGU General Assembly 2026, Vienna, Austria, 3–8 May 2026, EGU26-16268, https://doi.org/10.5194/egusphere-egu26-16268, 2026.
How to cite: Skeidsvoll, A. S., Laundal, K. M., Hatch, S. M., Madelaire, M., Popescu Braileanu, B., and Tesema Kebede, F.: Refined Modeling of Ionospheric Induction During the 24 October 2011 Sudden Commencement, EGU General Assembly 2026, Vienna, Austria, 3–8 May 2026, EGU26-19540, https://doi.org/10.5194/egusphere-egu26-19540, 2026.
Large Geomagnetically Induced Currents (GICs) are a key space weather hazard to ground-based infrastructure. These GICs act as a DC offset in typically AC power networks and when very large can cause mis-operation or even equipment failure. The dynamic solar wind interacts with the Earth’s geomagnetic field, causing the magnetic field as measured on the ground to vary with time. Via coupling with the geology of the solid Earth, this variability causes GICs to be created in grounded conducting networks. Most studies of the GIC hazard focus on short, fast changes of the geomagnetic field, for example large “spikes” in the one-minute rate of change of the horizontal geomagnetic field.
However, recent work has reminded researchers that long intervals of lower (relative) GIC can also be problematic, and represents a known pathway to equipment damage and long-lasting power failure. In this study we evaluate a curious interval where the power network in New Zealand experienced long duration, steadily increasing GICs across the South Island. These GICs were up to 20 A and lasted approximately 90 minutes, manifesting in the mid-latitude dawn sector during an otherwise moderate geomagnetic storm. We investigate the magnetospheric cause of the ground observations, and the ability of contemporary modelling techniques to capture this facet of the GIC hazard to ground-based infrastructure. Further, this case study highlights the limitations of geomagnetic indices, which we show to be vulnerable to contamination from such rare mid-latitude phenomena.
How to cite: Smith, A., Rodger, C., Rae, J., Coxon, J., Mac Manus, D., Malone-Leigh, J., Clilverd, M., Forsyth, C., Beggan, C., Pratscher, K., Richardson, G., Dimmock, A., Huebert, J., Petersen, T., Renton, A., Dalzell, M., and Walach, M.-T.: Large, Long-lasting Mid-Latitude Geomagnetically Induced Currents During a Moderate Geomagnetic Storm, EGU General Assembly 2026, Vienna, Austria, 3–8 May 2026, EGU26-6716, https://doi.org/10.5194/egusphere-egu26-6716, 2026.
Many of the effects of geomagnetic field variations, apart from those on devices using the geomagnetic field directly, are through induction of electric fields as described by Faraday’s Law. Such electric fields in turn cause an Ohmic effect in the Earth and conducting infrastructure, giving rise to potentially harmful geomagnetically induced currents (GIC). Precise measurement of the geomagnetic field dates back nearly two centuries, but localized measurements of geoelectric fields started mostly with magnetotelluric prospecting only in the mid-twentieth century. For this historical reason, and due to measuring difficulties now circumvented by modern technology, direct detection of geoelectric fields for space weather applications has rarely been done. We will describe efforts at Athabasca University to measure geomagnetic and geoelectric fields with a wide range of equipment, from commercial coil-based systems at 2400 Hz to extremely inexpensive systems based on microcontrollers and analog front ends. In principle, geoelectric field measurement devices can be simplified, and made inexpensive, more readily than those for geomagnetic fields, making networks of them a good way to monitor localized GIC effects. Recent cases of detection of large geoelectric fields in our region will be discussed.
How to cite: Connors, M., Schofield, I., and Cordell, D.: Induced Geoelectric Fields as a Key Space Weather Variable, EGU General Assembly 2026, Vienna, Austria, 3–8 May 2026, EGU26-15080, https://doi.org/10.5194/egusphere-egu26-15080, 2026.
Railways rely on interdependent systems for power, navigation, communications, and signalling, many of which are at risk of being impacted by space weather. Understanding how and to what extent space weather can impact these systems is crucial to maintaining the safe and reliable operation of railway networks.
Power supply disruption would leave trains on electrified lines stranded and can disrupt signalling operations, while geomagnetically induced currents introduced into the AC-electrified overhead line equipment can affect locomotive on-board transformers. GNSS disturbances can interfere with high-speed trains’ tilt control systems, limiting their speed and leading to delays. Loss of service of GSM-R (Global System for Mobile Communications Railway), which is used for communications and is an integral part of the advanced ETCS (European Train Control System), would impact operations. DC track circuit signalling systems on AC-electrified lines are susceptible to interference from geomagnetically induced currents which can lead to incorrect signals, causing delays or, in the worst case, collisions.
This presentation aims to provide an overview on our understanding of space weather impacts on railway systems, highlight recent work and identify potential avenues for future study.
How to cite: Patterson, C. and Wild, J.: Space Weather Impacts on Railway Systems, EGU General Assembly 2026, Vienna, Austria, 3–8 May 2026, EGU26-17750, https://doi.org/10.5194/egusphere-egu26-17750, 2026.
The success of marine magnetics to date the seafloor and reconstruct the evolution of basins in not to demonstrate anymore. However, some basins still remain poorly understood, either because of limited data coverage, tectonic complexity, or narrow width that do not allow full sequences of recognizable magnetic anomalies to be clearly identified. We propose new approaches that add to the classical identification of geomagnetic polarity reversal including the interpretation of tiny wiggles, i.e., low amplitude short wavelength anomalies that reflect paleointensity variations, and long wavelength anomalies that, in the absence of magnetized extrusive basalt, represent the contribution of the deeper oceanic crust. Examples of sea-surface and near-seafloor data where these approaches have helped to solve dating and reconstructing oceanic basin history will be presented.
How to cite: Dyment, J.: Marine magnetics: new approaches to solve plate tectonic problems in complex or narrow basins, EGU General Assembly 2026, Vienna, Austria, 3–8 May 2026, EGU26-21480, https://doi.org/10.5194/egusphere-egu26-21480, 2026.
The link between mantle heterogeneity as depicted by geochemical and seismic studies and the magmatism emplaced on the divergent plates remains elusive. Here, we derive variations of magmatism from marine magnetic data and trace mantle heterogeneities beneath the eastern Southwest Indian Ridge over 27 Ma. Three states of magmatism, robust, intermediate, and starved, are identified from the amplitude of magnetic anomalies. Comparing the distribution of magmatism on orthogonal and oblique ridge sections supports an asthenospheric source, not moving with the plates and ridge, as the predominant source of magmatic variations. These variations are therefore linked to different amounts of fertile and refractory mantle in the asthenosphere sampled by the ultraslow spreading center. In the study area, fertile mantle heterogeneities are 10 to 60 km-wide with the ridge migrating at 5 km/Myr in a N30°E direction. This study offers a new approach to constrain deep mantle heterogeneities from shallow crustal observations.
How to cite: Zhou, F., Dyment, J., Grevemeyer, I., and Liu, C.: Mantle heterogeneities induce time- and space-varying magmatism at the migrating ultraslow Southwest Indian Ridge, EGU General Assembly 2026, Vienna, Austria, 3–8 May 2026, EGU26-6673, https://doi.org/10.5194/egusphere-egu26-6673, 2026.
The core function of a marine geomagnetic diurnal variation observatory is to continuously collect geomagnetic diurnal variation data at a fixed ocean depth, and the quality of such data directly determines the accuracy of marine magnetic survey results. In the absence of this data, marine magnetic data cannot be precisely corrected, which in turn leads to significant errors in data processing and ultimately impairs the reliability of magnetic exploration outcomes.
At present, the Sentinel series geomagnetic diurnal variation observatories based on the Overhauser principle are widely adopted in China's marine magnetic survey sector. This paper presents a novel marine geomagnetic testing system developed on the basis of proton precession magnetometers, which offers three key advantages: first, it fills the domestic gap in independently developed products for marine geomagnetic diurnal variation observatories; second, it is designed with 6,000-meter ocean-specific glass floats, making it suitable for deep-sea deployment requirements; third, it achieves substantial improvements in both instrument performance and operational stability. The findings of this study provide an important reference for the technological iteration and application expansion of marine geomagnetic diurnal variation observatories.
How to cite: Chang, W.: Development and Application of Proton Magnetometers in Marine Geomagnetic Diurnal Variation Observatories, EGU General Assembly 2026, Vienna, Austria, 3–8 May 2026, EGU26-3720, https://doi.org/10.5194/egusphere-egu26-3720, 2026.
Long-period obliquity modulation can drive low-frequency hydroclimate variability by changing meridional insolation gradients and influencing the position and intensity of the East Asian monsoon rainband. What is less clear is how consistently such low-frequency signals are captured across different fine-grained depositional settings. Here we compare two end-member archives along the East Asian continental foreland: (i) dust-derived aeolian red clays in semi-arid regions near desert source areas, and (ii) organic-rich black shales deposited in more moisture-proximal settings, from lakes to shallow seas. The depositional processes are different, but both archives often damp higher-frequency noise and preserve long-period orbital pacing, which makes them useful for evaluating the timing and spatial pattern of monsoon-related hydroclimate change.
In the northern late Eocene red-clay succession from the eastern Mongolian Plateau, rock-magnetic and geochemical proxies show pronounced orbital-scale variability between ~48 and 36 Ma. Obliquity-paced modulation is clear, and wetter intervals cluster around high-obliquity nodes. The site sits in a continental-foreland position where moisture delivery from the south and southeast is likely sensitive to north–south shifts of the monsoon rainband and associated subtropical circulation changes.
For a deeper-time shale endmember, we examine Middle Triassic black-shale successions formed during warming and broader Earth-system reorganization. At that time, the North China and South China blocks lay along the eastern margin of Pangea, facing the ocean and remaining sensitive to changes in moisture supply. Geochemical series and magnetic susceptibility from lacustrine to shallow-marine settings show strong obliquity modulation, expressed as a ~1.2 Myr envelope with embedded ~173 kyr variability, together with a 405 kyr band. These patterns suggest that the ~1.2 Myr and ~173 kyr obliquity components can organize rainfall variability in both continental and marine fine-grained archives, and that this behavior extends back to at least ~250 Ma.
Next, using published evidence for cyclicity in Eocene shales from the East China Sea region, we will test whether similar long-period obliquity bands occur in Eocene marine black shales and whether their phases match those in the terrestrial red-clay record. Comparing red clays and black shales as products of a land–sea moisture gradient, using environmental magnetism together with cyclostratigraphy, offers a direct way to connect shale formation and monsoon climate forcing.
How to cite: Zhang, S. M.: Obliquity-modulated East Asian monsoon variability recorded coherently in fine-grained red clays and black shales across a land–sea moisture gradient, EGU General Assembly 2026, Vienna, Austria, 3–8 May 2026, EGU26-8289, https://doi.org/10.5194/egusphere-egu26-8289, 2026.
From its core to the magnetosphere and further into the solar wind, the Earth system is tightly coupled and the magnetic field is the glue that mediates the coupling. At the same time, the ionosphere behaves as a huge natural screen, where phenomena from above and below provide a broad range of complicated signatures, mapped along the magnetic field. The proper reading and disentangling of these signatures have a major potential to advance the fundamental understanding of the coupled Earth ‘spheres’ as well as of a vast set of applications and tools, covering from space weather and natural hazards to effects on space-borne and ground-based technology. While this is in principle well understood, the actual handling of the ionospheric observations and the tracing of the true sources behind ionospheric disturbances is often most challenging. The presentation will illustrate a few examples, emphasizing the major importance of the magnetic field in providing the coupling, of the ionosphere in screening it, and of a systematic approach yet to be done.
How to cite: Marghitu, O., Mandea, M., Astafyeva, E., and Balasis, G.: Magnetic field coupling across the Earth system as screened by the ionosphere, EGU General Assembly 2026, Vienna, Austria, 3–8 May 2026, EGU26-21137, https://doi.org/10.5194/egusphere-egu26-21137, 2026.
Posters on site: Wed, 6 May, 08:30–10:15 | Hall X2
Geomagnetically Induced Currents (GICs) are a manifestation of space weather events at ground level. GICs have the potential to cause power failures in electric grids. The GIC index is a proxy of the ground geoelectric field derived solely from geomagnetic field data. Information Theory (IT) can be used to shed light on the dynamics of complex systems, such as the coupled solar wind-magnetosphere-ionosphere-ground system. Previously, we have performed block entropy analysis of the GIC activity indices at middle-latitude European observatories around the St. Patrick's Day March 2015 intense magnetic storm and Mother's Day (or Gannon) May 2024 super-intense storm. We found that the GIC index values were generally higher for the May 2024 storm, indicating elevated risk levels. Furthermore, the entropy values of the SYM-H and GIC indices were higher in the time interval before the storms than during the storms, indicating transition from a system with lower organization to one with higher organization. Recently, IT has proven itself as a powerful approach to study causal relationships among various coupled complex systems. Here, we use Conditional Mutual Information as a measure of causality which is, indeed, the mutual information between the cause and the future of the effect variable, conditioned on the history of the effect variable, to investigate the possible coupling direction and pattern of interactions among different GIC indices, and various solar wind variables and geomagnetic activity indices.
How to cite: Boutsi, A. Z., Manshour, P., Papadimitriou, C., Balasis, G., and Palus, M.: Investigation of Geomagnetically Induced Current activity indices using Information Theory, EGU General Assembly 2026, Vienna, Austria, 3–8 May 2026, EGU26-9176, https://doi.org/10.5194/egusphere-egu26-9176, 2026.
Swarm data can be used to derive spaceborne indices of geomagnetic activity, capturing the same dynamic processes and exhibiting the same behaviour as ground-based geomagnetic indices traditionally used to monitor magnetic storm (SYM-H index) and substorm (AE index) activity. Given the fact that the official ground-based index for the substorm activity (i.e., the Auroral Electrojet – AE index) is constructed by data from 12 ground stations, solely in the northern hemisphere, it can be said that this index is predominantly northern, while the Swarm-derived AE index may be more representative of a global state, since it is based on measurements from both hemispheres. A few studies have addressed the question of whether the auroras are symmetric, between the northern and southern hemispheres. Therefore, the possibility to have different Swarm-derived AE indices for the northern and southern hemispheres respectively, may provide, under appropriate time series analysis techniques based on information theoretic approaches, an opportunity to further confirm the recent findings on interhemispheric asymmetry. Here, we also provide evidence for interhemispheric energy asymmetry in the ionosphere based on the analyses of Swarm-derived auroral indices AE North and AE South.
How to cite: Papadimitriou, C., Balasis, G., Boutsi, A. Z., and Daglis, I. A.: Evidence of Interhemispheric Asymmetry in Swarm Geomagnetic Activity Indices Using Complexity Measures, EGU General Assembly 2026, Vienna, Austria, 3–8 May 2026, EGU26-9977, https://doi.org/10.5194/egusphere-egu26-9977, 2026.
Rapid variations of the geomagnetic field represent both a resource and a hazard for modern technological systems. While geomagnetic observations support a wide range of applications, from navigation to positioning, storm-time magnetic disturbances can induce strong geoelectric fields at the Earth’s surface, driving geomagnetically induced currents (GICs) that threaten power grids and other grounded infrastructures. Accurate modelling of these ground effects critically depends on realistic representations of the Earth’s electrical conductivity.
In this contribution, we present the first results from the MARGE (Magnetotelluric ARray in Central Italy for GEoelectric hazard assessment) project, a measurement-driven initiative designed to provide the geophysical foundation for geomagnetic applications related to space-weather impacts. MARGE consists of a broadband and long-period magnetotelluric (MT) array deployed on a ~50 km grid across central Italy, a region characterized by strong lateral conductivity contrasts associated with active tectonics, sedimentary basins, volcanic provinces, and land–sea boundaries.
We describe the survey design, instrumentation, and data processing strategy, and assess the quality of 20 MT soundings acquired between 2023 and 2025. More than 75% of the sites yield good to excellent impedance estimates over periods from 10-3 to 104 s. Apparent resistivity, phase curves, and phase tensor analysis reveal pronounced spatial and depth-dependent variability of the electrical structure, highlighting the inadequacy of simplified one-dimensional conductivity models for geomagnetic applications in this region.
These first measurement-based results demonstrate the feasibility of constructing a realistic 3-D conductivity framework for Italy and represent a key step toward physics-based modelling of storm-time geoelectric fields. MARGE provides essential input for future GIC simulations and contributes to improving the reliability of geomagnetic-field-based applications and risk mitigation strategies.
How to cite: De Michelis, P., Balasco, M., Coco, I., De Girolamo, M., Di Persio, M., Giannattasio, F., Gizzi, C., Materni, V., Miconi, L., Miconi, M., Piangiamore, G. L., Pigniatiello, G., Romano, G., Romano, V., Santarelli, L., Sapia, V., Spadoni, S., Tozzi, R., Tripaldi, S., and Siniscalchi, A.: The MARGE magnetotelluric array in Central Italy: measurements and modelling perspectives for geomagnetic applications and geoelectric hazard assessment , EGU General Assembly 2026, Vienna, Austria, 3–8 May 2026, EGU26-14023, https://doi.org/10.5194/egusphere-egu26-14023, 2026.
Geomagnetically induced currents pose a well-recognized risk to ground-based technological systems during periods of intense geomagnetic activity. A key step in quantifying this risk is the reconstruction of the storm-time geoelectric field, which is controlled by the electrical conductivity structure of the subsurface. Although long-period magnetotelluric (MT) surveys provide optimal constraints for this purpose, many regions are covered primarily by legacy broadband MT datasets acquired for geological investigations and rarely exploited in a space-weather context. In this study, we investigate whether archived broadband MT data can be effectively used to estimate geoelectric fields relevant for GIC studies. We focus on the two most severe geomagnetic storms of 2024 (May and October), combining a broadband MT impedance tensor derived from three years of observations at the Gargano station (southern Italy) with 1 Hz magnetic field measurements from the nearby Duronia geomagnetic observatory. The analysis targets the 2–8000 s period range, which dominates GIC generation. Modeled electric field components are independently evaluated by comparison with storm-time electric field measurements decomposed into intrinsic mode functions using Empirical Mode Decomposition. The consistency between modeled and observed signals is assessed through Mutual Information analysis, revealing a statistically significant correspondence, particularly during storm main phases. These results show that legacy broadband MT datasets can provide quantitative and physically meaningful estimates of storm-time geoelectric fields. Existing MT archives therefore offer a valuable and cost-effective opportunity for preliminary GIC hazard assessment and retrospective space weather analyses, especially in regions lacking dedicated long-period MT coverage. This research was funded by the Space It Up! project funded by the Italian Space Agency, ASI, and the Ministry of University and Research, MUR, under contract n. 2024-5-E.0—CUP n.I53D24000060005.
How to cite: De Girolamo, M., De Michelis, P., Pigniatiello, G., Consolini, E., and Siniscalchi, A.: Linking Broadband Magnetotelluric Impedance, Magnetic Variations, and Geoelectric Field Dynamics in Severe Storms, EGU General Assembly 2026, Vienna, Austria, 3–8 May 2026, EGU26-16734, https://doi.org/10.5194/egusphere-egu26-16734, 2026.
The main object of this study is to trace the northern extension of the subsurface Spillway fault, Aswan, Egypt. To achieve this, we used two geophysical techniques, magnetic and passive seismic surface wave. Magnetic data provides insights into subsurface structures, basement depth and structural trends. While passive seismic surface wave technique (frequency-wavenumber) uses seismic surface waves (Rayleigh wave) to map the subsurface allowing for the evaluation the fault depth. This method relies on data collected from a sensor array that captures wave field information in order to obtain shear wave velocity models. In the current study, 10 microtremor arrays have been conducted north of Ben Ban solar plant location (north of Aswan city), in order to construct 2D profile for tracing the subsurface faults. The obtained results show graben fault, in which areas has low shear wave velocity value (350 m/s) confined between high shear wave velocity (1100 m/s) areas. Also, a detailed land magnetic survey has been carried out for the total component of the geomagnetic field using two overhauser magnetometers. The necessary corrections concerning daily variation, the regional gradient and time variations have been applied. Then, the total magnetic intensity anomaly map (TMI) has been constructed and transformed to the reduced to the pole magnetic map (RTP). The reduction-to-pole magnetic anomaly maps was used to obtain regional extensions of this subsurface structure. Regional–residual separation is carried out using the power spectrum. Also, Edge detection techniques are applied to delineate the structure and hidden anomalies various edge detection techniques including the tilt angle derivative, its total horizontal derivative, and 3D-Euler Deconvolution are applied to delineate the boundaries of these sources. The Euler solutions were superimposed on the tilt angle derivative map, revealing a strong correlation between the techniques, confirming their effectiveness in mapping the area's structural framework. The analysis indicates that the study area is influenced by multiple structural trends. Depth estimation was conducted using multiple approaches, yielding consistent results. The derived depths to the top of basement sources range from 300 to approximately 2500 meters. We can conclude that the obtained graben fault could be considered as an extension of the spillway fault
KEYWORDS
Land magnetic, frequency-wavenumber, Spillway fault, Euler Deconvolution, Edge detection and Spectral analysis.
How to cite: Khalil, A., El Emam, A., Hamed, A., Khalifa, M., and Khalaf, A.: Integrated Geophysical Studies for tracing the Northern Extension of the Subsurface Spillway Fault, Aswan, Egypt, EGU General Assembly 2026, Vienna, Austria, 3–8 May 2026, EGU26-288, https://doi.org/10.5194/egusphere-egu26-288, 2026.
The question of which orbital parameters (eccentricity, obliquity, and precession) drove Pleistocene variability in East Asian monsoon precipitation has become one of the enduring problems in paleoclimatology, yet a consensus remains elusive. Here, we test whether major sedimentary facies transformations can modify the orbital imprint preserved in climate archives by integrating environmental magnetic and non-magnetic proxies from a 954 kyr borehole (47°25′42″N, 125°55′00″E) in the Songnen Basin, NE China. We analyze magnetic susceptibility together with elemental contents and grain-size indices across intervals characterized by pronounced facies transitions. The χlf, χfd, Mn/Fe, Rb/Sr, Fe content, and the percentage of >32 μm (%) show significant correlations with lithological transitions over time. The shift from swamp/peat to lacustrine facies is marked by a notable decline in χlf, Rb/Sr, and Fe flux, while χfd, Mn/Fe, and the percentage of >32 μm (%) exhibit a clear increase. The transition from lacustrine to marginal lacustrine facies shows relatively minor but still distinct changes, with χfd, Mn/Fe, Fe flux, and the percentage of >32 μm (%) increasing significantly. The most pronounced transition occurs around 200 ka, changing aqueous to eolian deposition. During this period, χlf, χfd, and Mn/Fe rise sharply, the Rb/Sr ratio continues to decline, and Fe flux and the percentage of >32 μm (%) display a stable trend with weaker amplitude fluctuations compared to before 200 ka. Spectral and evolutionary spectral analyses show that the dominant orbital periodicity is consistently expressed across facies changes, indicating that facies transformation does not fundamentally reorganize the primary orbital pacing recorded in this sequence. In contrast, the relative power and temporal stability of specific orbital bands vary among proxies, implying proxy-dependent sensitivity rather than archive-dependent forcing. We attribute these differences to differential responses of regional climate components (i.e., temperature, effective moisture, and lake-level variability) to orbital forcing, which in turn regulate magnetic mineral concentration and grain size, detrital input, and chemical transport pathways. Our results highlight that discrepancies among orbital-forcing reconstructions of East Asian rainfall arise mainly from how individual proxies encode climate conditions, rather than from changes in the geological archive itself.
How to cite: Gao, Z., Wang, Z., Cao, M., Hou, H., Ren, B., Zhang, Z., and Zhang, R.: Does sedimentary facies transformation modulate the recording of orbital forcing? Insights from environmental magnetism and multi-proxy data in the Songnen Basin (NE China), EGU General Assembly 2026, Vienna, Austria, 3–8 May 2026, EGU26-2059, https://doi.org/10.5194/egusphere-egu26-2059, 2026.
This study explores the origin and evolution of magnetic fields in planetary bodies and galaxies, focusing on the role of an initial seed magnetic field (SMF) required for dynamo operation. We propose a general physical mechanism in which a seed field arises naturally in systems where an orbiting body rotates non-synchronously relative to its central mass. Building on this idea, we derive a unified formulation for the SMF that is applicable across both planetary and galactic scales and incorporates fundamental parameters such as orbital distance, rotational velocity, and core radius. To relate the seed field to observed magnetic field strengths, we introduce a dimensionless parameter that represents the efficiency of dynamo amplification. Model predictions are compared with magnetic field measurements from the solar system and the Milky Way. The results suggest that observed magnetic fields can be interpreted as the product of a universal, gravity-induced seed field and a system-dependent amplification factor. This framework offers a complementary perspective on magnetic field generation in a wide range of astrophysical environments and highlights potential implications for magnetism in extreme settings, including regions surrounding black holes.
How to cite: De Santis, A., Dini, R., and Cianchini, G.: From Seed Fields to Magnetism in Planets and Galaxies, EGU General Assembly 2026, Vienna, Austria, 3–8 May 2026, EGU26-10283, https://doi.org/10.5194/egusphere-egu26-10283, 2026.
Extremely high-energy SEPs, which attain energies in the GeV range, are accelerated during impulsive solar flares and in association with CMEs. These relativistic particles represent a primary driver of hazardous space weather phenomena. They pose significant risks to spacecraft operations and crew safety during deep-space missions, while also threatening ground-based infrastructure, particularly power grids and other critical components of the electromagnetic environment, through geomagnetic disturbances and induced currents. Spectral observations indicate that the acceleration of SEPs to GeV energies involves highly complex, multi-component processes characterized by diverse ion compositions. The particle population predominantly comprises hydrogen (protons and electrons, approximately 73%), helium (approximately 25%), and heavier ions. Notably, the mass-to-charge ratio (A/Q) differs markedly between helium isotopes: 1.5 for ³He²⁺ and 2.0 for ⁴He²⁺.
In the present study, we examine the acceleration processes and ³He enrichment in SEP events within a statistical plasma-physics framework integrated with turbulence theory. Our methodology explicitly accounts for the realistic proton-to-electron mass ratio, the distinct mass-to-charge ratios of relevant ion species, and the effects of turbulence resistivity and viscosity. These elements are incorporated into a fully coupled hydrodynamics–magnetohydrodynamics–kinetic model that bridges continuous spatial and temporal scales, thereby circumventing the traditional separation of micro-kinetic and macro-dynamic regimes.
Numerical simulations are conducted on a supercomputer using our newly developed relativistic hybrid particle-in-cell and lattice-Boltzmann method (RHPIC-LBM) code. This advanced computational approach facilitates self-consistent modeling of the multi-scale, multiphase dynamics underlying the extreme ³He enhancements observed in impulsive solar SEP events. The simulations reveal that high-frequency magnetic fluctuations at kinetic scales play a pivotal role in generating self-organized perturbations. Concurrently, plasma velocity fluctuations sustain and amplify these waves through self-feeding mechanisms. When the frequency of these perturbations approaches the Langmuir oscillation frequency, resonant wave–particle interactions become particularly efficient. Langmuir turbulence, driven by nonlinear resonant wave–particle coupling, preferentially accelerates ions whose resonance conditions match those of ³He. This selective resonance renders the acceleration of ³He substantially more efficient than that of ⁴He, thereby providing a compelling explanation for the extreme ³He enrichment characteristic of impulsive SEP events.
How to cite: Li, Y., Zhu, B., and Zhao, Y.: ³He Enrichment in SEP Events: Observational Constraints and Evidence from Isotopic Fractionation via Resonant Wave–Particle Interactions and Turbulent Acceleration, EGU General Assembly 2026, Vienna, Austria, 3–8 May 2026, EGU26-16097, https://doi.org/10.5194/egusphere-egu26-16097, 2026.
Alternative magnetic navigation (aka MagNav) depends on matching of onboard sensor readings with prior mapping of the Earth’s magnetic field. Three critical components to successful MagNav are (1) sensor accuracy, (2) magnetically clean sensor platform with compensation for any residual platform effects, and (3) reference map quality. Relatively inexpensive magnetic sensors are sufficient for successful MagNav. Established methods are sufficient to calibrate all but the noisiest platforms. The purpose of this presentation is to dig into (3); specifically, how to assess the quality of directional magnetic anomaly gradients (DMAG) from magnetic maps and deliver the most reliable reference values to nav systems. At each navigation time step a comparison is made between the measured and mapped gradients. Successful MagNav depends on the ability to quantify the level of match between these values. A critical component is an understanding of the characteristics of uncertainty in the estimation of DMAG for input to the navigation filter algorithm.
Current navigation systems ingest magnetic map data as a “stack of grids” prepared from an original survey grid by upward continuation (typically using an FFT method). Anomaly values and east-west/north-south gradients are interpolated from these grids for comparison with magnetic sensor data in the navigation filter. The reliability of these anomaly and gradient values is dependent on several factors, including the uncertainty in the original survey grid, edge effects or other artefacts from upward continuation, and method of grid interpolation. The use of an equivalent source model instead of a stack of static grids offers opportunities for uncertainty propagation and ability to query anomaly and gradient values and related uncertainty at arbitrary locations and cadence. The purpose of this presentation is to give comparative examples of DMAG evaluations using different methods applied to synthetic and actual data.
How to cite: Saltus, R., Chulliat, A., and Califf, S.: Navigating from Magnetic Maps – Improving Reliability of Magnetic Anomaly and Gradient Reference Values from Imperfect Data, EGU General Assembly 2026, Vienna, Austria, 3–8 May 2026, EGU26-14369, https://doi.org/10.5194/egusphere-egu26-14369, 2026.
The Earth’s magnetic field (EMF), generated by geodynamo processes, varies across multiple timescales ranging from years to billions of years. Integrated analyses of paleodirectional and paleointensity data over the past 10 million years reveal persistent non-dipolar features in the Southern Hemisphere, linked to the South Atlantic Magnetic Anomaly (SAA). However, the spatial and temporal coverage of high-quality paleomagnetic data remains uneven and is particularly scarce in South America. To address this gap, we provide new paleodirections and paleointensities from different volcanic units in Argentina, Colombia and Brazil. New paleodirectional data were obtained from 23 sites of the Auca Mahuida Volcano (0.19-1.53 My; Argentina) by thermal and alternating field demagnetisation protocols. Paleointensity data were obtained from 41 sites in Colombia, Brazil, and Argentina, ranging in age between 0.005-1.95 My using multiple experimental methods, including Triaxe, Wilson, Thermal Thellier, Microwave Thellier, and the Double Heating Technique of Shaw (DHT-Shaw).
The magnetic mineralogy of the studied volcanic rocks comprises dominantly low-Ti titanomagnetite, as indicated by thermomagnetic curves with susceptibility drop between 550 °C and 580 °C and IRM curves with saturation fields below 300 mT. FORC analyses and Day diagrams reveal the dominance of the Pseudo Single Domain (PSD) state of the magnetic grains. Directional data for the Auca Mahuida Volcano yielded a mean direction (D =356.4°, I = -52.04° and α95 = 6.4°; N = 14; K>50; Vandamme cutoff) that is statistically indistinguishable from the expected direction for a geocentric axial dipole (GAD) field (IGAD = −57.0°) in that location, within the 95% confidence limits. The corresponding VGP dispersion Sb =12.799.3°15.9° agrees well with other studies carried out in the Southern Hemisphere and Paleosecular Variation (PSV) models.
Out of 332 specimens analysed in paleointensity experiments, approximately 20% met our selection quality criteria (f>0.3, n>4, 𝛽<0.1, MADANC<15, DRAT<10, CDRAT<15). Virtual Dipole Moments (VDMs) ranged from 2.45× 10²² Am² to 8.02× 10²² Am² (8 sites in Argentina), 1.64× 10²² Am² to 9.29× 10²² Am² (5 sites in Colombia), and 5.17× 10²² Am² to 5.49× 10²² Am² (2 sites, in Brazil). Most of the normal and reversed sites exhibit paleointensity values within the 95% confidence limits of the geomagnetic field predicted in models such as PADM2M and MCADAM 1b, with two exceptions (Argentina) in 0.34 My and 1.36 My showing values of 3.6× 10²² Am² and 1.19× 10²² Am², respectively, while transitional data display significantly lower intensities (e.g., 2.45× 10²² Am²).The dispersion (Sb) of the VGPs using alternative selection criteria shows higher values in the analysed sites compared with the expected values for the Southern Hemisphere, deviating from regional PSV models. The variability in paeointensity values, sometimes lower than those predicted by the consulted models, may be related to the presence of the SAA. Further studies and data will be required. The new Paleomagnetic data from various volcanic bodies in South America will contribute to expanding the database for the last 10 Million Years, thereby enhancing the model's accuracy and providing better constraints on its boundary conditions.
How to cite: Aguilar Moncada, S., Hartmann, G. A., Oliveira, W. P., Biggin, A. J., Trinidade, R., Pasqualon, N. G., Coppi, D. A., da Silva, G. S., Savian, J. F., Lima, E. F., da Luz, F. R., Nova, G., Parra, M., Sommer, C. A., Báez, A. D., Caselli, A. T., Franco, D. R., and Terra-Nova, F.: New Paleomagnetic Data from South America and Implications for the Southern Hemisphere Geomagnetic Field Evolution, EGU General Assembly 2026, Vienna, Austria, 3–8 May 2026, EGU26-1241, https://doi.org/10.5194/egusphere-egu26-1241, 2026.
The Early Paleozoic paleogeographic position of the South China Block (SCB) and its affinity with Gondwana remain contentious. This study presents new, high-quality paleomagnetic data from Cambrian Stage 3 clastic rocks (Kunming, southwestern SCB) that quantitatively constrain its early Paleozoic paleogeography.
Systematic analyses identify a primary remanent magnetization carried by detrital magnetite. This component passes fold and reversal tests, shows no significant inclination shallowing, and averages out secular variation. Following a regional Cenozoic rotation correction, the paleopole positions the SCB at a paleolatitude of ~13.6°S at ~518 Ma. This location places its outhwestern margin adjacent to the western margin of East Gondwana. Paleogeographic reconstructions illustrate a contiguous spatial relationship and a concordant margin orientation between the two blocks.
Our new paleomagnetic pole, supported by existing paleobiogeographic and provenance data, firmly establishes the SCB as a constituent part of East Gondwana from the Early Cambrian to Early Devonian (~520–405 Ma). These results provide robust evidence for refining Cambrian paleogeographic models of Gondwanan assembly.
How to cite: Zhang, D., Cheng, X., Kravchinsky, V. A., and Wu, H.: New Cambrian paleomagnetic constraints on South China Block paleogeography and Gondwana linkages , EGU General Assembly 2026, Vienna, Austria, 3–8 May 2026, EGU26-8660, https://doi.org/10.5194/egusphere-egu26-8660, 2026.
Nihewan Basin is one of a series of well-developed East Asian Cenozoic basins in Hebei Province, North China, which are rich sources of mammalian faunas and Paleolithic sites. During the past decades, detailed magnetostratigraphic dating was conducted on the Nihewan Formation and associated mammalian faunas and Paleolithic sites, and the results have contributed significantly to our understanding of the chronostratigraphy of the Nihewan Basin.
The Pulu fauna, one of the Nihewan faunas (sensu lato), is located on the eastern bank of the Huliu River in the Nihewan Basin and contains mammalian fauna in the late Pliocene to early Pleistocene. Here, we selected the fluvio-lacustrine deposits containing the Pulu mammalian fauna to conduct detailed rock magnetic and high-resolution magnetostratigraphy studies, combined with biostratigraphic and lithostratigraphic results, to precisely constraint on the Pulu mammalian fauna. In this study, 466 oriented samples were collected from the fluvio-lacustrine sequences of Pulu section (thickness 112 m) for detailed rock magnetic and magnetic fabric studies. The results showed that the magnetic minerals in the fluvio-lacustrine deposits of the Pulu section are mainly magnetite, maghemite and hematite, with predominantly pseudo-single domain. The Pulu fluvio-lacustrine deposits recorded the early Brunhes normal chron, the Matuyama reverse chron, the Gauss normal chron and the late Gilbert reverse chron. The Pulu mammalian fauna was found during the pre-Réunion Matuyama chron and the post-Kaena Gauss chron with the age about 3.0-2.2 Ma. This study has extended the lower age of the Nihewan faunas to about 3.0 Ma. Furthermore, the paleoclimatic and paleoenvironmental studies in the Nihewan Basin suggested that the evolutionary direction of the Nihewan faunas were influenced by changes in climate and environment during the Pliocene and Pleistocene transitions, and Nihewan faunas evolved towards adapting to a cold and arid environment.
How to cite: Liu, P., Li, J., and Gao, X.: Magnetostratigraphic dating of the Pulu mammalian fauna in the Nihewan Basin, North China, EGU General Assembly 2026, Vienna, Austria, 3–8 May 2026, EGU26-3369, https://doi.org/10.5194/egusphere-egu26-3369, 2026.
Eolian red clays provide one of the few terrestrial archives that can track East Asian dust transport and hydroclimate variability beyond the Quaternary loess–paleosol sequence. Over the past decades, a growing body of magnetostratigraphic and cyclostratigraphic work has steadily pushed the upper age limit of astrochronologically resolved eolian red-clay records from the familiar ~3 Ma interval on the Chinese Loess Plateau to much older Cenozoic time slices. Here we synthesize this stepwise extension and highlight how environmental magnetism has been central to establishing an orbital-scale stratigraphic framework across a wide range of source–sink settings.
On the Loess Plateau, orbital-scale variability is well expressed in magnetic susceptibility and related rock-magnetic parameters, enabling robust dating over the late Neogene (~8 Ma) and, in the western Plateau, into the early Miocene (>20 Ma). Subsequent discoveries farther west expanded the record dramatically: red-clay successions near the eastern margin of the Tibetan Plateau (Altun region) preserve orbitally paced variability back to ~50 Ma, while sections along the northern Junggar Basin extend to ~25 Ma. In the eastern Erlian Basin (Inner Mongolia), continuous fine-grained red clays document cyclicity reaching at least ~48 Ma. Most recently, even older Cenozoic eolian red-clay sequences (~60 Ma) have been identified by us in the Qinling region, suggesting that dust-bearing winds and low-frequency hydroclimate pacing were established early in the Cenozoic and remained persistent across shifting paleogeography and boundary conditions.
Across these regions, magnetic susceptibility and complementary rock-magnetic proxies consistently capture astronomical forcing, with prominent long-period eccentricity and obliquity modulation embedded within precession-scale variability, despite clear differences in depositional setting, distance to desert sources, and post-depositional alteration. Treating the Cenozoic red-clay belt as a spatially distributed “network” of archives allows us to (i) test the reproducibility and phase stability of orbital signals across basins, (ii) evaluate how dust supply and pedogenic processes filter orbital forcing, and (iii) refine Cenozoic terrestrial timescales where independent radiometric constraints are limited. This synthesis shows that Cenozoic eolian red clays, when anchored by magnetostratigraphy and analyzed with cyclostratigraphy, can provide a coherent astrochronological framework from ~3 to ~60 Ma and open a path to reconstruct long-term East Asian dust–monsoon evolution on orbital timescales.
How to cite: Zhang, R., Ma, M., Gong, H., Sagnotti, L., and Kravchinsky, V. A.: From loess to deep-time red clays: magneto-cyclostratigraphy reveals orbital pacing in East Asian dust archives back to ~60 Ma, EGU General Assembly 2026, Vienna, Austria, 3–8 May 2026, EGU26-13735, https://doi.org/10.5194/egusphere-egu26-13735, 2026.
Abstract: Nuclear magnetic resonance (NMR) mapping, valued for its non‑destructive nature and high resolution, is extensively employed in geological exploration to analyze the distribution of geological structures, mineral resources, and other subsurface targets. However, the intrinsic low sensitivity of NMR limits its utility in weak‑signal environments. Dynamic nuclear polarization (DNP) overcomes this constraint by using radiofrequency excitation to transfer polarization from electron spins to nuclear spins. This mechanism effectively relays the high polarization of electrons to the nuclear spin system, markedly boosting NMR detection sensitivity and serving as a pivotal signal‑enhancement strategy.
Within DNP systems, nitroxide radicals are widely studied due to their chemical stability and synthetic accessibility. However, their polarization efficiency is often limited by the magnetic transition characteristics of the conventional nitrogen nucleus. To address this, the present study established an electron paramagnetic resonance (EPR) spectral simulation method based on software such as Gaussian and ORCA. Guided by this approach, a novel nitroxide radical was designed and synthesized with the aim of enhancing DNP performance at low to medium magnetic fields. EPR experimental results show that this radical exhibits a narrow EPR linewidth and higher unpaired electron transition intensity compared to conventional nitroxide radicals. These properties enable it to overcome the electron transition energy limitations of conventional nitroxide radicals under medium- and low-field conditions, thereby achieving a higher nuclear polarization rate.
In conclusion, this study introduces an efficient design strategy centered on a novel nitroxide radical, which substantially improves DNP signal enhancement and supports the advancement of NMR mapping technology.
How to cite: Jiang, Y. and Li, X.: A Study on the Dynamic Nuclear Polarization Efficiency of a Novel Nitroxide Radical, EGU General Assembly 2026, Vienna, Austria, 3–8 May 2026, EGU26-9315, https://doi.org/10.5194/egusphere-egu26-9315, 2026.
Aerogeophysical survey is an exploration method that uses aircraft as the carrier, carries geophysical prospecting instruments to detect geophysical field information during flight, and studies the internal structure and material composition of the Earth based on the collected data to solve geological problems. This method is not restricted by terrain and enables efficient and rapid survey operations. At present, the application of low-altitude magnetic survey in iron ore exploration has become quite mature in China. Unmanned aerial vehicle (UAV) aeromagnetic systems are also increasingly sophisticated in such fields as onshore mineral resource exploration and geological structure survey, but their application in marine surveys is still in the initial stage.
The working principle of aeromagnetic survey is that the UAV carries magnetic sensors for magnetic field observation, which specifically consists of seven components: 1. Flight carrier system; 2. Airborne aeromagnetic survey system; 3. Ground control station; 4. Ground magnetic diurnal variation base station; 5. Work auxiliary equipment; 6. Field data preprocessing system; 7. Data interpretation system.
This paper mainly introduces the application of aeromagnetic survey in nearshore submarine pipeline detection. The UFO-CS multi-rotor cesium optical pump aeromagnetic survey system, independently developed and manufactured by Beijing Orangelamp Geophysical Exploration Co., Ltd., is adopted for measurement and data interpretation in this application.
How to cite: Wang, Y. and Chang, W.: Application of Cesium Optical Pump UAV Aeromagnetic System in Coastal Shallow Water Areas, EGU General Assembly 2026, Vienna, Austria, 3–8 May 2026, EGU26-9029, https://doi.org/10.5194/egusphere-egu26-9029, 2026.
With the advancement of science and technology and the development of human society, there is an increasing demand for higher precision in magnetic field measurement. The proton precession magnetometer is precisely such an instrument capable of accurately measuring the geomagnetic field. As a high-precision magnetic field measuring device, it has been widely applied in high-precision magnetic surveys, mineral exploration, tectonic detection, seismic and volcanic precursor observation, engineering and environmental exploration, coalfield and hydrogeological exploration, pipeline and underground explosive detection, archaeology, petroleum and natural gas exploration, and other industries, thanks to its stable performance, compact size, ease of portability and simple operation.
This paper introduces a high-precision proton precession magnetometer developed by Beijing Orangelamp Geophysical Exploration Co., Ltd., with a detailed description and analysis of its working principle, appearance, functions, operation procedures and performance tests. This high-precision proton precession magnetometer has been widely used in the Chinese market and has received favorable feedback.
The high-precision proton precession magnetometer described in this paper adopts GPS or BDS (BeiDou Navigation Satellite System) for time synchronization, eliminating the tedious process of manual time input. In a favorable magnetic field environment, its noise level can reach 0.05 nT. Moreover, it is compatible with a dedicated free magnetic data processing software package developed by Beijing Orangelamp Geophysical Exploration Co., Ltd. The absolute error of this proton precession magnetometer is also controlled within ±0.5 nT.
How to cite: Binti Serasa, N. A. S., Chang, W., Zhao, Y., and Shenshuo, H.: A High-Precision GPS/BeiDou-Synchronized Proton Precession Magneto, EGU General Assembly 2026, Vienna, Austria, 3–8 May 2026, EGU26-8676, https://doi.org/10.5194/egusphere-egu26-8676, 2026.
Posters virtual: Mon, 4 May, 14:00–18:00 | vPoster spot 1a
EGU26-3254 | Posters virtual | VPS29
Theoretical Foundations and Methodological Developments in the Study of Particle Transport Mechanisms and Microstructural Evolution Employing the Hybrid Quantum Monte Carlo–Boltzmann Transport ModelMon, 04 May, 14:15–14:18 (CEST) vPoster spot 1a
Within the comprehensive framework of the Sun–Earth system, plasma environments exhibit an exceptionally wide range of physical conditions. These encompass the ultra-high-temperature, high-pressure, and high-density liquid metallic outer core of Earth, which generates the geomagnetic field through the geodynamo process; the tenuous, partially ionized ionosphere; and the magnetosphere, which provides essential shielding against energetic cosmic and solar radiation while exerting substantial influence on human technological systems, most notably microwave communication infrastructure. In addition, transient ultra-high-temperature plasmas generated by solar flares and coronal mass ejections (CMEs) represent the primary drivers of disturbed space electromagnetic environments, as they propagate through interplanetary space and subsequently interact with Earth's magnetosphere.Although prior research has extensively employed the first-principles quantum Monte Carlo method coupled with the lattice Boltzmann approach (FPQM-LBM) to address various theoretical and computational aspects of plasma behavior in this context, no existing modeling framework has successfully integrated — within a single consistent methodology — the extreme conditions of the Earth's outer core plasma, the low-density ionospheric plasma, the magnetospheric plasma, and the highly energetic, transient flare/CME plasmas. As a result, a unified and comprehensive understanding of particle transport mechanisms and internal structural properties across the full spectrum of plasma regimes in the Sun–Earth system remains elusive.The present study aims to address this critical gap by developing novel theoretical frameworks and advanced computational methodologies for elucidating the particle migration mechanisms and structural characteristics of space electromagnetic plasmas throughout the panoramic Sun–Earth system. To this end, we will enhance the first-principles quantum Monte Carlo–lattice Boltzmann method (FPQM-LBM) to establish robust techniques capable of modeling particle transport under the complex electromagnetic conditions prevailing in space environments. The improved FPQM-LBM framework will be systematically applied to simulate particle dynamics across the aforementioned plasma regimes — namely, the ultra-high-temperature/pressure/density outer core plasma, the low-density ionosphere, the magnetosphere, and transient flare/CME plasmas — with particular emphasis on ionic characteristics, microstructural evolution, fine-scale particle transport processes, internal structural transformations, and the response of plasma properties to external electromagnetic perturbations. The anticipated results are expected to furnish a solid theoretical foundation and valuable predictive capabilities for advancing solar–terrestrial space physics and enhancing electromagnetic monitoring and forecasting in space weather research.
How to cite: Zhu, B.: Theoretical Foundations and Methodological Developments in the Study of Particle Transport Mechanisms and Microstructural Evolution Employing the Hybrid Quantum Monte Carlo–Boltzmann Transport Model, EGU General Assembly 2026, Vienna, Austria, 3–8 May 2026, EGU26-3254, https://doi.org/10.5194/egusphere-egu26-3254, 2026.
EGU26-6969 | Posters virtual | VPS29
Research Progress on SEPs on the Fine Structures of the Large Temporal-spatial Current Sheets in Solar Flares/CMEsMon, 04 May, 14:18–14:21 (CEST) vPoster spot 1a
During intense solar atmospheric activity—such as major solar flares and geomagnetic storms—magnetic energy is converted into plasma kinetic and thermal energy through three-dimensional turbulent magnetic reconnection within large-scale, extended current sheets. This process releases enormous amounts of stored energy, often accompanied by the rapid ejection of high-energy particles into interplanetary space. These high-energy particles include electrons, protons, helium nuclei, and heavier ions, forming a complex multi-component, multi-abundance, and multi-isotopic population. Their energies span from ~100 keV to ~100 MeV and even into the GeV range, making them a primary driver of space weather hazards. Understanding the sources and acceleration mechanisms of these particles remains one of the most critical challenges in space weather research. Previous studies have shown that high-energy particle acceleration is highly complex, involving multiple species, a variety of mechanisms, and interactions across scales. It remains an open and challenging problem in solar and plasma physics. This paper provides a systematic review and forward-looking perspective on recent advances in high-energy particle acceleration during the fine-scale evolution of large-scale current sheets. The discussion is organized around three key pillars: theory, observations, and numerical simulations. First, we summarize the turbulence-fractal model as it applies to typical solar atmospheric events. We focus on acceleration mechanisms in turbulent magnetic reconnection within large spatiotemporal current sheets, with particular emphasis on: Turbulent (second-order) Fermi acceleration, Turbulent shock acceleration, and Turbulent wave-particle resonant acceleration. These mechanisms operate synergistically in the turbulent environment generated by reconnection, enabling efficient energy transfer to particles. Second, we review recent progress in coupling macroscopic (hydrodynamic and magnetohydrodynamic) dynamics to microscopic kinetic processes in high-energy particle acceleration. This includes multi-scale modeling of turbulence, reconnection, and particle transport. Finally, we outline promising future research directions, including improved multi-spacecraft observations, higher-resolution simulations that incorporate kinetic effects, and integrated models that bridge MHD turbulence and particle-in-cell approaches. We also highlight several urgent unresolved issues, such as the relative contributions of different mechanisms across energy regimes, the role of fractal structures in particle trapping and escape, and the origin of observed abundance enhancements in heavy ions. This review synthesizes recent theoretical, observational, and computational developments to provide a comprehensive framework for understanding high-energy particle acceleration in large-scale turbulent current sheets, with implications for solar flares, space weather forecasting, and broader astrophysical plasma processes.
How to cite: Zhu, B.: Research Progress on SEPs on the Fine Structures of the Large Temporal-spatial Current Sheets in Solar Flares/CMEs, EGU General Assembly 2026, Vienna, Austria, 3–8 May 2026, EGU26-6969, https://doi.org/10.5194/egusphere-egu26-6969, 2026.
EGU26-5611 | Posters virtual | VPS29
Improving GIC modelling and validation with high-quality information on power network parametersMon, 04 May, 14:21–14:24 (CEST) vPoster spot 1a
Space weather can affect the operation of high voltage AC transformers in power grids by applying an offset DC current during periods of heightened geomagnetic activity. Modelling GIC requires knowledge of magnetic field variation, the response of the local subsurface geoelectric field (related to conductivity) and a representation of the connections between transformers and various resistance parameters of the power network. Presently, in Britain, the largest uncertainty in this chain applies to the resistance parameters of the network, as these values come from open-source data which are known to have many approximations.
Recent work with a transmission network operator in the UK has provided us with an improved dataset of resistance parameters of transformers, power lines and substation grounding. The grounding resistance at electrical substations has not been known before and so historically was set at 0.5 Ω in our models. The new dataset of 110 sites around central Scotland reveals substation grounding resistance varies from 0.04 Ω to 11.7 Ω with a mean of 0.54 Ω but a median of 0.2 Ω. Combined with line and transformer resistance information, we have created an improved representation of the power grid in Scotland.
Using GIC measurements from three sites (Torness, Strathaven and Neilston) for the largest geomagnetic storms in the past 25 years (October 2003, September 2017 and May 2024), we are able to validate the new model, demonstrating its improved accuracy.
The new model demonstrates that our previous assumptions of grounding resistance were too high but our estimate of line resistance was too low, thus balancing out the overall GIC magnitude on average. However, in detail, some locations show large differences in GIC compared to the original model. This highlights the importance of using accurate resistance information to correctly capture GIC.
How to cite: Beggan, C., Richardson, G., and Lawrence, E.: Improving GIC modelling and validation with high-quality information on power network parameters, EGU General Assembly 2026, Vienna, Austria, 3–8 May 2026, EGU26-5611, https://doi.org/10.5194/egusphere-egu26-5611, 2026.
EGU26-9301 | ECS | Posters virtual | VPS29
The influence of the heterogeneity (stratification) of the outer core fluid on the variation of the geomagnetic fieldMon, 04 May, 14:24–14:27 (CEST) vPoster spot 1a
The Earth's magnetic field is divided into internal and external sources, with the internal field including the main magnetic field, the crustal magnetic field, and the induced magnetic field. Among these, the main magnetic field accounts for approximately 95% of the Earth's total magnetic field. Data from paleomagnetic records in rocks, various geomagnetic observatories, and satellites indicate that the main magnetic field exhibits westward drift, polarity reversals, intensity decay, and brief geomagnetic excursions at the core-mantle boundary. To explain these phenomena, several models have been proposed in previous studies. The prevailing view is that the outer core is composed of liquid metal, and the Earth's main magnetic field is generated by the turbulent fluid motion of this liquid metal, influenced primarily by factors such as its composition and properties, thermal convection, Lorentz force, and Coriolis force. Considering the strong Coulomb forces between electrons and ions, previous research has usually treated the electrons and ions in the outer core's metallic fluid as a unified component, greatly simplifying the study and achieving satisfactory results. However, existing studies have not taken into account the differences in motion between ions and electrons under the dynamics of the outer core, the resulting spatial distribution differences of electrons and ions in the outer core, or the impact of these differential distributions on the Earth's main magnetic field. In view of this, This paper studies the effect of the factors generating outer core dynamics on the distribution of electrons and ions in the outer core. It examines the distribution of electrons and ions in the outer core space under equilibrium conditions and estimates their contribution to Earth's main magnetic field. Then, by changing parameter conditions (such as temperature gradients) and adding convective terms (non-equilibrium state), the calculations are redone. These results are used to explain changes in Earth's magnetic field.
How to cite: Wang, S., Li, Y., Zhu, B., Zhao, Y., Wang, Q., and Liu, H.: The influence of the heterogeneity (stratification) of the outer core fluid on the variation of the geomagnetic field, EGU General Assembly 2026, Vienna, Austria, 3–8 May 2026, EGU26-9301, https://doi.org/10.5194/egusphere-egu26-9301, 2026.
