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.

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 investigating the spatial and temporal correlation lengths of small-scale and mesoscale FAC (field-aligned current) structures at auroral latitudes. Stationarity features of small-scale FACs (10–50 km scale size) are temporal length < 18 s and correlation length < 12 km. For mesoscale FACs (75–220 km scales) we obtain a stability of > 40 s and correlation length > 20 km.

A configuration of field-aligned currents (FACs) that can explain the rapid variation in the geomagnetic field in mid-latitude Europe on 29 October 2003 was recently proposed. Interestingly, this specific system of the FACs might also explain the famous Carrington event on 2 September 1859. By analysing the declination observed in mid-latitude Europe on 29 October 2003, we confirmed an important feature of the proposed current system, the westward movement of one of the FACs.

This study focuses on a TIMED Doppler Interferometer (TIDI)–meteor radar (MR) comparison of zonal and meridional winds and their dependence on local time and latitude. The correlation calculation between TIDI wind measurements and MR winds shows good agreement. A TIDI–MR seasonal comparison and analysis of the altitude–latitude dependence for winds are performed. TIDI reproduces the mean circulation well when compared with MRs and may be a useful lower boundary for general circulation models.

It is often the case that only magnetic field data are available for in situ planetary studies using spacecraft. Either plasma data are not available or the data resolution is limited. Nevertheless, the theory of plasma instability tells us how to interpret the magnetic field data (wave frequency) in terms of flow speed and beam velocity, generating the instability. We invent an analysis tool for Mercury's upstream waves as an example.

The electric state of the Earth’s atmosphere is manifested in the surface electric potential gradient (PG). In fair weather the PG should follow the variation of the global source of electric current in the atmosphere, called the global electric circuit. The PG is also influenced by local conditions. We use long-term series of PG and analyse PG variations during conditions of low aerosol concentrations to minimise the aerosol influence on PG obscuring its change due to the global source.

This study investigates an ionospheric anomaly in Antarctica that affects electron concentration during summer. We analyse data from four stations, revealing different trends depending on the season and time of day. Vernadsky shows strong influence of the anomaly, while Port Stanley is less affected, and other stations do not show a clear pattern. These results highlight how local phenomena can modify global trends, providing new information about the Earth's space environment.