Waves on the boundary of our magnetic shield, the magnetosphere, act as a source of electrical currents in space that flow between outer space and the ionised top of our atmosphere. We develop a simple numerical model of how these waves couple to different regions of geospace to determine their likely impacts in the context of space weather and how these vary with conditions. We find the waves’ impacts can be significant, though are typically highly localised.

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.

We provide an introduction and overview about the initial Submillimetre Wave Instrument (SWI) characterization, operation, and in-flight calibration during the Lunar Earth Gravity Assist (LEGA) campaign of the Juice (Jupiter icy moons) spacecraft. A preliminary analysis on the frequency calibration is provided. For detailed analyses on total power and beam calibration and the observation and operations planning we refer to three other SWI papers prepared for this special issue of Annales Geophysicae (ANGEO).

We created a new computer model to study gravity waves, which are ripples in the atmosphere that affect weather and climate. Our research aimed to improve how these waves are simulated, as they play a key role in understanding atmospheric behavior. We developed a stable and efficient model that can model gravity waves in the atmosphere. Our method is fast and accurate, offering better tools for scientists to predict atmospheric changes.

Fourier spectral analysis is applied to the planetary geomagnetic index $A_p$ for the February 2001, 2003, and 2017 time intervals. 

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.

Atmospheric winds at high altitudes (> 100 km) can play an important role in the electrodynamic processes that govern how ionospheric plasma interacts with Earth's neutral atmosphere. Here we investigate how a common idea in studies of ionospheric electrodynamics—that atmospheric winds can be ignored or represented via an average value—ignores the high variability of these winds. This variability forces a different formulation of the equations that govern ionosphere-thermosphere electrodynamics.

The High Accuracy Accelerometer calibrated data collected during the JUICE (JUpiter ICy moons Explorer) Lunar Earth Gravity assist flyby was compared with predicted non-gravitational signals derived from analytical models, showing good agreement. Moon gravity gradient and thermoelastic displacement of solar array during the penumbra phases have been detected. High Accurate Accelerometer detected also unexpected signals such as instrument interference and outgassing event.

Coronal mass ejections (CMEs) threaten Earth. We studied their interaction with the magnetosphere and ionosphere. Using the European Heliospheric Forecasting Information Asset (EUHFORIA), we calculated CME arrival times and investigated Earth's responses. Results show EUHFORIA and Gorgon-Space codes agree well in simulating CME propagation and interactions.

The study utilized a stratospheric balloon over Natal, Brazil, to investigate the atmospheric response to the 14 October 2023 annular solar eclipse near sunset. Measurements included temperature, pressure, relative humidity and ozone. Significant changes in these parameters were found at different altitudes. These complex changes confirm the importance of the annular eclipses as a driver of localized atmospheric dynamics.

The Lower Thermosphere-Ionosphere energy balance is driven by complex interactions between ions, neutrals and electrons. These processes are understood theoretically, but their estimates show large discrepancies between models. We calculate the storm-time energy budget according to the neutrals, ions and electrons using TIE-GCM (Thermosphere Ionosphere Electrodynamics General Circulation Model) using two different external drivers. Discrepancies between the model runs are discussed and the way forward to close the gaps in present knowledge is highlighted.

The Jupiter Icy Moons Explorer is a spacecraft sent towards Jupiter to perform detailed observations of the giant gas planet & its Galilean satellites. The Submillimetre Wave Instrument onboard this spacecraft is a newly built instrument, which first of all has to demonstrate proper performance before the observed data can be trusted. Using the Earth as a well-known observation target, proper functionality of this instrument has been verified during the Lunar Earth Gravity Assist in August 2024.

Rapid geomagnetic variations in the ultra-low frequency band are observed using ground-based magnetometers. We apply four years of data from West Greenland in a statistical analysis of the distribution of such variations. We identify a rapid geomagnetic variation 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 variations.

We present an updated spectral and radiometric calibration of the Moons and Jupiter Imaging Spectrometer (MAJIS) aboard the Jupiter Icy Moons Explorer (JUICE), based on results of Earth and Moon observations in August 2024 and on observations of the MAJIS internal calibration unit. Very good agreements were obtained with results of other instruments and models. These MAJIS observations provide a promising teaser of what will be achieved by MAJIS in the system of Jupiter.

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 308 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.

This study investigates 40 geomagnetic storms driven by corotating interaction regions and their impact on Earth's magnetotail. We find that short, 4 h energy pulses dominate the magnetotail during cyclic substorms. Furthermore, High-Intensity, Long-Duration, Continuous Auroral Activity (HILDCAA) events in the recovery phase facilitate energy distribution across 2–12 h periodicities in the auroral region. Spectral indices indicate strong turbulence in both regions.

Auroras are caused by energetic electrons entering the upper atmosphere. For the smallest and most dynamic auroras, scientists think electrons are accelerated by waves (called Alfvén waves) thousands of kilometers above Earth. In this paper, we analyse data from a rocket that flew through auroras, applying existing and new techniques to estimate where the acceleration took place. Our results match theory, and we show how they can be used to study conditions in the near-Earth space environment.