Analysis of the sub-auroral region response to the September 2017 geomagnetic storm 

Agata Chuchra - Space Research Centre of Polish Academy of Sciences; Barbara Matyjasiak - Space Research Centre of Polish Academy of Sciences, Poland; Hanna Rothkaehl - Space Research Centre of Polish Academy of Sciences, Poland; Mariusz Pożoga - Space Research Centre of Polish Academy of Sciences, Poland; Łukasz Tomasik - Space Research Centre of Polish Academy of Sciences, Poland 

Session: Thermosphere-Ionosphere Interactions and Effects

Abstract

A geomagnetic storm is a major disturbance of Earth’s magnetic field and results from variations in the solar wind which can be caused e.g. by Coronal Mass Ejections from the Sun. The traveling magnetic cloud can produce significant changes in electrical currents, circulation, composition, temperature and density of plasma in the magnetosphere-ionosphere-thermosphere system. The energy injection into the magnetosphere through the magnetotail reconnection affects directly the auroral region of the Earth’s ionosphere, where energetic particles precipitation, auroral oval expansion, and variations of plasma density and field-aligned current intensity can be observed during geomagnetic storms. The September 2017 storm was an extreme and complex event during the 24th solar cycle minimum, that resulted in dynamic changes in Earth’s auroral region. As an ionospheric trough region is a kind of a boundary region where physical processes of different origin can act, we are willing to present an analysis of variations in plasma density, intensity of field-aligned currents, and variability of the ionospheric trough structure during the geomagnetic storm of 6-8 September 2017. The interaction and correlation of the mentioned parameters are studied in the context of different phases of the event. Analysis is based on the data from the Swarm mission.