The study makes use of magnetic field data from the closely spaced Swarm A and C spacecraft during the counter rotating orbit phase. It allows to investigate the spatial and temporal correlation lengths of small- and meso-scale FAC structures at auroral latitudes. Stability features of small-scale FACs (10–70 km wavelength) are: temporal <18 s, correlation length <12 km. For meso-scale FACs (100–300 km wavelength) we obtain a stationarity of >40 s and correlation length >42 km.

This study redefines our understanding of the factors influencing changes during solar eclipses by integrating observations of the interplanetary magnetic field (IMF) lines, winds, and gravity waves within the lunar umbra cone. This integration leads to a novel theory that reveals a magnetic vortex in the moon's wake that explains the origins of these changes and their impact on the atmosphere, winds, and Foucault's pendulum.

Flux ropes are peculiar structures of twisted magnetic field occurring in many regions of space, near Earth and other planets, at the Sun, and in astrophysical objects. We developed a new way of detecting flux ropes in large supercomputer simulations of near-Earth space and we use it to follow the evolution of flux ropes for long distances past the Earth in the flow direction. This will be useful in future studies as these flux ropes are involved in the transport of matter and energy in space.

We studied the first broad band emissions, called continuum, in the dayside aurora. They are similar to STEVE with white, pale pink or mauve coloured light. But unlike STEVE, they follow the dayside aurora forming rays and other dynamic shapes. We used ground optical and radar observations and found evidence of heating and upwelling of both plasma and neutral air. This study provides new information on conditions for continuum emission, but its understanding will require further work.

This study explores how different particle temperatures and distributions affect electromagnetic waves in space. We found that these factors significantly alter wave behavior compared to traditional theories.

This research explores how Hydrogen ions and Oxygen ions move and gain energy in Earth’s magnetosphere at high altitudes and latitudes. Using Monte Carlo simulations, predictions of mean particle theory, and corresponding observations, we compared different energy profiles of Hydrogen and Oxygen ions across polar wind, aurora, cusp, and central polar cap. Our findings reveal that unique interactions in each area affect energy gain differently, with implications for future space weather models.

Our research explored the "shock aurora," caused by the impact of solar wind particles on Earth's magnetic field. On February 26, 2023, we observed this rare event on the nightside, where such observations are difficult. Ground-based cameras revealed new structural features, including undulating and jumping patterns. These results provide fresh insights into the complex interactions between the solar wind and Earth's magnetosphere, enhancing our understanding of space weather effects.

We study how well the F10.7 and F30 solar radio fluxes represent solar energy input in the thermosphere during the last 60 years. We found that increased saturation of radio fluxes at recent solar minima leads to an overestimation of solar energy, which change the relation between thermospheric parameters and F10.7, but this is not an issue for F30 because of a relative increase of F30 with respect to F10.7. This explains why F30 has been found to represent solar energy better than F10.7.

Electromagnetic emissions stimulated by powerful radio waves in the ionosphere exhibit an exponential power spectrum. Such a spectrum is a characteristic of deterministic chaos. A relevant model of parametrically excited localized lower hybrid oscillations is derived. Numerical simulations show that for parameter values typical of the ionospheric experiments, the temporal evolution may exhibit deterministic chaos with an exponential spectrum that is consistent with the experimental results.

In previous works, we found Euler potentials for the combined magnetic field of Earth's dipole, field aligned currents, ring current, and the magnetopause surface currents (represented by Dungey's term), in the magnetosphere. The determination of shell currents is difficult.

The complete time series of the geomagnetic disturbance index (K) from Norwegian magnetic observatories have been digitized. We compare and discuss the tree methods used to derive the index, finding that each method both have strengths and weaknesses. In total, we present all K-indices derived from Norwegian observatories since the 1930s until today, the used derivation methods and the long, historic time-series as a whole, enabling a critical use for future scientific work.

It is typically thought that the protons which precipitate down from space to cause proton aurora are accelerated by a type of plasma wave called an EMIC wave. In this study we use ground-based observations of proton aurora and Pc1 waves (the ground signature of EMIC waves) to test whether this mechanism occurs in the high Arctic over Svalbard, on the Earth's day side. We did not find any link between the proton aurora and Pc1 pulsations, contrary to our expectations.