Mantle movements 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. Using InSight data, 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.

To study global thunderstorm activity we analysed the Schumann Resonance electromagnetic field driven by lightning. We developed formulas to calculate both the distance and the size of thunderstorm areas from frequency changes of either the magnetic or the electric resonance modes alone. Our method can be used by observatories worldwide, which mainly record magnetic fields. This novel technique improves our ability to monitor and understand global lightning activity.

Dune aurora is an intriguing phenomenon recently discovered thanks to citizen science. It is a dim, diffuse auroral form exhibiting wave-like stripes of brighter emission. We carry out the first statistical study of dune aurora, using 289 observation reports submitted to the Skywarden database by citizen scientists from Europe, North America, and Oceania. We find that dunes are an evening phenomenon, most often reported in March and October and associated with currents in the auroral atmosphere.

GHOST is a pale mauve aurora, usually seen near noon in Svalbard during polar night, emitting a continuum spectrum across the visible range. Our fitting of high-resolution spectra shows that GHOST emission is best explained by extremely hot nitrogen and oxygen molecules, not by the more scarce nitrous oxide which is usually assumed. We propose that strong ionospheric flows, daylight, and incoming solar‑wind particles combine to heat the upper atmosphere, priming it to produce GHOST aurora.

We used infrared data from the MAJIS instrument on the Jupiter Icy Moons Explorer during its 2024 lunar flyby to map the Moon’s temperature and infrared emission at the time of the overpass. By comparing three analysis methods, we confirmed known contrasts between maria and highlands and showed how surface texture shapes their infrared signal. These results help prepare MAJIS for studying the diverse and unexplored moons that orbit Jupiter.

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.

During the 10–11 May 2024 geomagnetic storm, the red auroral rays appear at higher altitudes and connect to green rays lower down. The effect is linked to energetic electrons precipitating into the atmosphere during the storm. As the electrons continue downward, they hit oxygen below 200 km altitude and produce green light (5577 Å), named Stable Auroral Green (SAG) arcs. These observations mark the first reported sightings of such detailed, combined features. 

This article investigates high-latitude medium scale traveling ionospheric disturbances (MSTIDs) over the EISCAT-3D site. Utilizing Hankasalmi radar data during solar max & min years of solar cycles 23 & 24, we observed that high-latitude MSTIDs’ normally propagate equatorward with velocity and period in the range of 50–150 m s^-1 and 30–60 minutes, respectively. Along with the seasonal variation, their occurrence showed dependency on solar activity as well as on northward and southward IMF Bz.

Ultra-low frequency (ULF) signals are observed using ground based magnetometers. We apply four years of data from West Greenland in a statistical analysis of ULF signal distribution as a function of season, latitude, local time, and solar wind conditions. We identify a ULF signal population associated with the magnetospheric cusp that is separate from the auroral oval during summer. Earlier studies, which were mainly performed in winter, failed to unambiguously identify these signals.

This paper presents large scale changes to the ionosphere that were observed over a large portion of the continental US from 200 – 450 km altitude during the April 2024 solar eclipse. We observed a decrease in electron density of 50 %, a drop in electron and ion temperatures of 40 % and 20 % respectively. Unique features included lower densities and temperatures north of the eclipse path as compared to the south, and ion temperature decrease along a narrow region parallel to the eclipse path.

Long-term analysis of 16 solar eclipses over south-central Chile using historical ionograms (1958–2024). Layer-dependent ionospheric responses were quantified, and fragile analog records were rescued and digitized, providing unique insights into eclipse-induced ionospheric variability.

The goal of this study was to explore how a once-in-a-century storm 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.

This study shows the first observations of the upflow of ions in the Earth's ionosphere generated by ultra-low frequency waves. These waves are visible as auroral arcs. Using various instruments and models, their complex dynamics and the coupling between the ionosphere and magnetosphere were highlighted. Results show significant energy dissipation and currents, even from small-scale waves, highlighting the importance of a multi-instrument approach to understanding such phenomena.

Sawtooth events are storm‑time surges of energetic particles with sharp rises and slow decays repeating every 2–4 h. From 2008–2016 they occur mostly in the solar cycle’s declining phase and nearly always during geomagnetic storms. Geostationary data show near‑global, near‑simultaneous injections but strong magnetic changes only at midnight. This favors magnetotail reconnection and fast convection; sawteeth resemble a storm‑time substorm mode.