https://angeo.copernicus.org/articles/ Combined list of the recent articles of the journal Annales Geophysicae and the recent discussion forum Annales Geophysicae Discussions en https://doi.org/10.5194/angeo-44-461-2026 Juice-SWI during the Lunar-Earth-Gravity-Assist (LEGA) – Part 2: Instrument operations Thibault Cavalié, Raphael Moreno, Ladislav Rezac, Fabrice Herpin, Christopher Jarchow, Paul Hartogh, Alberto Carrasco Gallardo, Samuel Goodyear, Pierre Mancini, Ali Schulz-Ravanbakhsh, Borys Dabrowski, Yasuko Kasai, Emmanuel Lellouch, Axel Murk, Donal Murtagh, Michael Olberg, Miriam Rengel, Hideo Sagawa, Slawomira Szutowicz, and Eva Wirström Ann. Geophys., 44, 461–487, https://doi.org/10.5194/angeo-44-461-2026, 2026 The Submillimetre Wave Instrument (SWI) aboard the Juice mission is a sophisticated and first-of-its-kind payload. SWI is designed to support the diverse science objectives of the Juice mission targeting Jupiter's middle atmosphere, icy-moon's exospheres as well as near sub-surface thermophysical properties. This presents significant planning, operations and commanding challenges which are described in this paper in the context of the Lunar and Earth Gravity Assist (LEGA). Wed, 10 Jun 2026 10:05:45 +0200 https://doi.org/10.5194/angeo-44-435-2026 Spectroscopic detection of terrestrial lightning from space by JUICE-MAJIS during Earth Gravity Assist Emiliano D'Aversa, Fabrizio Oliva, Giuseppe Piccioni, François Poulet, Ivana Kolmašová, Benoît Seignovert, Alessandra Migliorini, Gianrico Filacchione, Leigh Fletcher, Alessandro Mura, Yves Langevin, Davide Grassi, Sébastien Rodriguez, Federico Tosi, Nicolas Ligier, Giuseppe Sindoni, Marco Giardino, and Christina Plainaki Ann. Geophys., 44, 435–460, https://doi.org/10.5194/angeo-44-435-2026, 2026 Terrestrial lightning has been spectroscopically observed from Juice (JUpiter ICy moons Explorer) spacecraft, for the first time from space in a wide wavelength range. Though not detected by ground sensors, Juice confirmed neutral atomic oxygen and nitrogen emissions, with energies and temperatures consistent with average lightning. This observation is a benchmark for Jupiter, a primary Juice target, where simultaneous hydrogen emissions in different wavelengths could identify lightning. Thu, 04 Jun 2026 10:05:45 +0200 https://doi.org/10.5194/angeo-44-405-2026 New technique for isolating the auroral contribution in UV imagery: IMF By dependence of seasonal differences in auroral oval location during positive IMF Bz Jens Christian Hessen, Jone Peter Reistad, Spencer Mark Hatch, Karl Magnus Laundal, and Yongliang Zhang Ann. Geophys., 44, 405–433, https://doi.org/10.5194/angeo-44-405-2026, 2026 Auroras, the natural lights seen in Earth's sky near the poles, are shaped by both Earth's and the solar wind's magnetic fields, as well as charged solar particles. This study examines how auroras change when the solar wind's magnetic field is dawn-dusk oriented. Daytime observations are challenging due to sunlight, so we developed a method to further separate auroras from background light. In summer, auroras shift east or west with/against the solar wind's magnetic field. Fri, 29 May 2026 10:05:45 +0200 https://doi.org/10.5194/angeo-44-391-2026 Pre-earthquake Electric Field Disturbances and Interference Analysis Based on CSES-01 Satellite Observations Jianping Huang, Junjie Song, Yantao Zhang, Yuan Yao, Zhong Li, Wenjing Li, Hengxin Lu, Xingsu Li, Yumeng Huo, and Ruiqi Yang Ann. Geophys., 44, 391–403, https://doi.org/10.5194/angeo-44-391-2026, 2026 In this paper, we propose a method for identifying anomalous electromagnetic phenomena in the ionosphere before earthquakes, contributing to earthquake prediction research. By analyzing satellite data from the China Seismo-Electromagnetic Satellite and applying a decomposition technique, we identify significant electric-field disturbances prior to the May 11, 2023, Tonga Islands earthquake, supporting studies of seismic precursors. Wed, 27 May 2026 10:05:45 +0200 https://doi.org/10.5194/angeo-44-369-2026 Transport coefficients in standard Kappa distributed plasmas: a comparative study Mahmood J. Jwailes, Imad A. Barghouthi, and Qusay S. Atawnah Ann. Geophys., 44, 369–390, https://doi.org/10.5194/angeo-44-369-2026, 2026 Space plasmas often deviate from the usual thermal pattern assumed in most models. Using the standard Kappa distribution, we derived how this non-thermal energy spread alters electrical flow, heat transfer, and particle motion. We found that stronger deviations lower collision rates and enhance transport coefficients, while normal behaviour returns in the thermal limit, which improves our insight into space environments. Fri, 22 May 2026 10:05:45 +0200 https://doi.org/10.5194/angeo-44-353-2026 High-latitude MSTIDs over the EISCAT-3D site: solar activity and seasonal dependency Rahul Rathi, Adrian Grocott, Tim K. Yeoman, and Mark Lester Ann. Geophys., 44, 353–368, https://doi.org/10.5194/angeo-44-353-2026, 2026 We investigate high-latitude medium scale traveling ionospheric disturbances (MSTIDs) over European Incoherent Scatter (EISCAT)-3D site. Using Hankasalmi radar data during solar max & min years of solar cycles 23 & 24, we observed that MSTIDs normally propagate equatorward with velocity and period of 50–150 m s-1 and 30–60 minutes, respectively. Along with seasonal variation, MSTIDs showed dependency on solar activity as well as on northward and southward interplanetary magnetic field (IMF) Bz. Tue, 19 May 2026 10:05:45 +0200 https://doi.org/10.5194/angeo-44-331-2026 Studies of noctilucent clouds from the stratosphere during the 2024 TRANSAT balloon flight Peter Dalin, Hidehiko Suzuki, Nikolay Pertsev, Vladimir Perminov, Linda Megner, Johan Kero, Peter Voelger, Jonas Hedin, Gerd Baumgarten, Anne Réchou, and Denis Efremov Ann. Geophys., 44, 331–351, https://doi.org/10.5194/angeo-44-331-2026, 2026 A transatlantic scientific balloon flight (TRANSAT) was conducted in June 2024. The TRANSAT balloon floated in the stratosphere at approximately 40 km altitude between Sweden and Canada for about 4 days. An optical imager was installed on the TRANSAT balloon to study noctilucent cloud (NLC). Nearly continuous observations of NLC were obtained during the entire flight. A complex NLC structures exhibiting different motions were found to result from wind rotation with altitude between 80 and 94 km. Mon, 18 May 2026 10:05:45 +0200 https://doi.org/10.5194/angeo-44-303-2026 Next-generation Ionospheric Model for Operations – validation and demonstration for space weather and research Angeline G. Burrell, Sarah McDonald, Dustin Hickey, Meghan Burleigh, Eliana Nossa, Christopher A. Metzler, Manbharat Dhadly, Jennifer L. Tate, and Ellen J. Wagner Ann. Geophys., 44, 303–329, https://doi.org/10.5194/angeo-44-303-2026, 2026 The Next-generation Ionospheric Model for Operations (NIMO) is a space weather model developed to provide historic, current, and forecasted information about the density of the ionosphere. This article discusses how NIMO is configured, demonstrates potential use cases for the research community, and validates historic runs using a new suite of metrics designed to allow repeatable, quantitative, model-independent evaluations against observations that may be adopted by other ionospheric models. Thu, 23 Apr 2026 10:05:45 +0200 https://doi.org/10.5194/angeo-44-287-2026 Effect of a non-hydrostatic core-mantle boundary on the nutations and Length-of-day of Mars Marta Folgueira López, Véronique Dehant, Mihaela Puica, and Tim Van Hoolst Ann. Geophys., 44, 287–301, https://doi.org/10.5194/angeo-44-287-2026, 2026 Mantle mass anomalies can deform Mars’ core–mantle boundary (CMB). Unlike Earth’s mainly degree 2–order 2 pattern, Mars’ Tharsis and crustal dichotomy cause multiple deformation types. Here, researchers studied how dynamic CMB topography affects Mars’ nutations and length-of-day (LOD). They found the main (though tiny) effect on nutations comes from degree 2–order 2, while LOD changes are too small to detect. Thu, 23 Apr 2026 10:05:45 +0200 https://doi.org/10.5194/angeo-44-263-2026 Subauroral contamination in POES/Metop TED channels Jan Maik Wissing, Olesya Yakovchuk, Stefan Bender, and Christina Arras Ann. Geophys., 44, 263–285, https://doi.org/10.5194/angeo-44-263-2026, 2026 We investigate the subauroral flux maximum (at 60° N/S geomagetic) observed in low-energy particle channels. Two independent atmospheric impact measurements refute the subauroral flux under low Kp, pointing to instrumental contamination, likely from energetic electrons. We propose correction methods to mitigate contamination, ensuring accurate ionization estimates. Without correction, subauroral flux overestimates thermospheric ionization, underscoring the need for data refinement. Thu, 09 Apr 2026 10:05:45 +0200 https://doi.org/10.5194/angeo-44-245-2026 Benchmarking the Swedish Power Grid Against a 1-in-100-Year Geoelectric Field Scenario Vanina Lanabere, Andrew P. Dimmock, Sven Molenkamp Venholen, Alice V. L. Wallner, Andreas Johlander, Lisa Rosenqvist, and Johan Setréus Ann. Geophys., 44, 245–261, https://doi.org/10.5194/angeo-44-245-2026, 2026 The goal of this study was to explore how a once-in-a-century geoelectric field event could affect the Swedish power grid by combining past storm data with a simplified model of the power grid. We identified regions that may be at higher risk and estimated how many power lines could be exposed to large voltages. These insights reveal vulnerable areas and provide a foundation for strengthening preparedness against rare, high-impact events. Wed, 08 Apr 2026 10:05:45 +0200 https://doi.org/10.5194/angeo-44-227-2026 Mapping transition region flows to the ionosphere in a global hybrid-Vlasov simulation Venla Koikkalainen, Maxime Grandin, Emilia Kilpua, Abiyot Workayehu, Ivan Zaitsev, Liisa Juusola, Shi Tao, Markku Alho, Lauri Pänkäläinen, Giulia Cozzani, Konstantinos Horaites, Jonas Suni, Yann Pfau-Kempf, Urs Ganse, and Minna Palmroth Ann. Geophys., 44, 227–243, https://doi.org/10.5194/angeo-44-227-2026, 2026 We use a numerical simulation to study phenomena that occur between the Earth’s dipolar magnetic field and the nightside of near-Earth space. We observe the formation of large-scale vortex flows with scales of several Earth radii. On the ionospheric grid of the simulation we find that the field-aligned currents formed in the simulation reflect the vortex flow in the transition region. The main finding is that the vortex flow is a result of a combination of flow dynamics and a plasma instability. Fri, 27 Mar 2026 10:05:45 +0100 https://doi.org/10.5194/angeo-44-209-2026 The impact of electron precipitation on Earth's thermospheric NO production and the drag of LEO satellites Manuel Scherf, Sandro Krauss, Grigory Tsurikov, Andreas Strasser, Valery Shematovich, Dmitry Bisikalo, Helmut Lammer, Manuel Güdel, and Christian Möstl Ann. Geophys., 44, 209–225, https://doi.org/10.5194/angeo-44-209-2026, 2026 We model the structure of the thermosphere for two space weather events that affected satellite orbits. Based on the Sun's irradiation, we simulate atmospheric density profiles and feed them into a model that calculates the influence of precipitating electrons on nitrogen oxide production in the atmosphere. Our results underscore the importance of considering both solar irradiance and particle precipitation to understand and predict space weather effects on the atmosphere and satellite orbits. Mon, 16 Mar 2026 10:05:45 +0100 https://doi.org/10.5194/angeo-44-195-2026 Variability and trend analysis of temperature and height in the upper troposphere and stratosphere region over the tropics (Réunion), by combining balloon-sonde and satellite measurements Gregori de Arruda Moreira, Hassan Bencherif, Tristan Millet, and Damaris Kirsch Pinheiro Ann. Geophys., 44, 195–207, https://doi.org/10.5194/angeo-44-195-2026, 2026 Tropopause temperature and height serve as key indicators of anthropogenic climate change. However, monitoring their variability remains challenging due to the sparse distribution of observation stations, particularly in the Southern Hemisphere. To address this, we compared temperature profiles from three datasets—SHADOZ, COSMIC-1, and MERRA-2—to assess their similarities and differences and to develop a refined dataset for trend analysis. Thu, 05 Mar 2026 10:05:45 +0100 https://doi.org/10.5194/angeo-44-163-2026 ESA/JUICE encounters Earth/Moon in 2024: overview of the Moons And Jupiter Imaging Spectrometer (MAJIS) observations François Poulet, Giuseppe Piccioni, Yves Langevin, Cydalise Dumesnil, Vincent Carlier, Benoit Seignovert, Marc Dexet, Leigh N. Fletcher, Cédric Leyrat, Francesca Altieri, John Carter, Emiliano D'Aversa, Maria De Sanctis, Davide Grassi, Sandrine Guerlet, Stéphane Le Mouélic, Alessandra Migliorini, Fabrizio Oliva, Clément Royer, Sébastien Rodriguez, Katrin Stephan, Federico Tosi, Francesca Zambon, Alberto Adriani, Gabriele Arnold, Jean-Pierre Bibring, Dominique Bockelée, Rosario Brunetto, Fabrizio Capaccioni, Cristian Carli, Thibault Cavalié, Miriam Cisneros González, Mauro Ciarnello, Simone De Angelis, Pierre Drossart, Gianrico Filacchione, Thierry Fouchet, Jean-Claude Gérard, Denis Grodent, Patrick Irwin, Sophie Jacquinod, Ozgur Karatekin, Emmanuel Lellouch, Nicolas Ligier, Nicolas Mangold, Magali Mebsout, Frédéric Merlin, Alessandro Morbidelli, Alessandro Mura, Andreas Nathues, Maria E. Palumbo, Cédric Pilorget, Olivier Poch, Eric Quirico, Andrea Raponi, Séverine Robert, Elias Roussos, Agustin Sanchez-Lavega, Bernard Schmitt, Giuseppe Sindoni, Marcel Snels, Roberto Sordini, Stefania Stefani, Giovanni Strazzulla, Tim Trent, Gabriel Tobie, Diego Turrini, Ann-Carine Vandaele, Mathieu Vincendon, Olivier Witasse, Claire Vallat, and Alessandro Moraino Ann. Geophys., 44, 163–193, https://doi.org/10.5194/angeo-44-163-2026, 2026 During the double Lunar-Earth Gravitational Assist with the ESA/JUICE (Jupiter Icy Moons Explorer) spacecraft in August 2024, we acquired hyperspectral data cubes of both the Moon and Earth with the MAJIS (Moons And Jupiter Imaging Spectrometer) imaging spectrometer under challenging, real in-flight conditions. This allowed to characterize surface materials and thermophysical properties on the Moon, identify various cloud phases and gases in Earth's atmosphere, and thoroughly validate the performance of the instrument. Tue, 03 Mar 2026 10:05:45 +0100 https://doi.org/10.5194/angeo-44-149-2026 A source or a sink? How the altitude of particle precipitation influence high-latitude electrodynamics Magnus F. Ivarsen Ann. Geophys., 44, 149–162, https://doi.org/10.5194/angeo-44-149-2026, 2026 When energetic particles rain into Earth’s lower ionosphere, they ionize the gas, creating a highly conductive base layer. Using a large database of observations from four orbiting space weather satellites, we demonstrate that this plasma foundation acts as a giant electrical short-circuit: it actively neutralizes the electric fields that would otherwise power plasma turbulence higher up. Without this conductive base to drain the energy, topside turbulence freely grows and persists. Thu, 26 Feb 2026 10:05:45 +0100 https://doi.org/10.5194/angeo-44-137-2026 Earth's magnetosheath: a comparison of plasma flow direction between models and observations Marek Vandas and Evgeny Romashets Ann. Geophys., 44, 137–148, https://doi.org/10.5194/angeo-44-137-2026, 2026 Observations of the plasma flow direction in the Earth’s magnetosheath are compared with the help of three analytical magnetic-fieldmodels, namely Kobel and Flückiger (1994), Romashets and Vandas (2019), and Vandas and Romashets (2019), which all assume current-free fields in the magnetosheath. 47 magnetosheath passages by spacecraft are analyzed in detail and performance of the models are evaluated. It is concluded that the performances are comparable. Wed, 25 Feb 2026 10:05:45 +0100 https://doi.org/10.5194/angeo-44-123-2026 Effect of Ionospheric Variability on the Electron Energy Spectrum estimated from Incoherent Scatter Radar Measurements Oliver Stalder, Björn Gustavsson, and Ilkka Virtanen Ann. Geophys., 44, 123–135, https://doi.org/10.5194/angeo-44-123-2026, 2026 The rapid changes in ion composition during auroral are dynamically modeled by integrating the coupled continuity equations for 15 ionospheric species. The effect of the ionospheric variation on the inversion of incoherent scatter radar (ISR) electron density profiles to differential energy spectra of precipitating electrons is studied. A systematic overestimation at high electron energies can be removed using a dynamic model. Comparisons are made with static and steady-state ionospheric models. Tue, 17 Feb 2026 10:05:45 +0100 https://doi.org/10.5194/angeo-44-109-2026 Data reduction of incoherent scatter plasma line parameters Mini Gupta and Patrick Guio Ann. Geophys., 44, 109–122, https://doi.org/10.5194/angeo-44-109-2026, 2026 The ionosphere, formed by atmospheric ionization, contains free electrons and ions. Incoherent Scatter Radar probes it using high-frequency electromagnetic pulses, revealing ionospheric properties. Plasma lines, weak at thermal equilibrium, are enhanced and become detectable due to strong solar or auroral activity. This study develops methodologies to detect plasma lines, showing their strength decreases as the scattering radar beam is more oblique to the Earth's magnetic field. Tue, 10 Feb 2026 10:05:45 +0100 https://doi.org/10.5194/angeo-44-85-2026 Plasma density estimation from ionograms and geophysical parameters with deep learning Kian Sartipzadeh, Andreas Kvammen, Björn Gustavsson, Njål Gulbrandsen, Magnar G. Johnsen, Devin Huyghebaert, and Juha Vierinen Ann. Geophys., 44, 85–107, https://doi.org/10.5194/angeo-44-85-2026, 2026 Knowledge of the charged environment in the upper atmosphere is essential for understanding space weather effects on satellites and radio communication. This environment is difficult to estimate at high latitudes, where aurora cause strong variability. We developed an artificial intelligence model to estimate this environment continuously. Our results show that the model provides reliable estimates even during auroral activity, improving monitoring of the polar upper atmosphere. Tue, 03 Feb 2026 10:05:45 +0100