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Variation of plasma pressure in the inner magnetosphere during geo-magnetic storms and substormsтезисы доклада
- Авторы: Stepanova M., Antonova E.E., Romanova N., Martínez-Ledesma M., Rojas-Gamarra M., Moya P., Pinto V.
- Сборник: Abstracts of 43th COSPAR Scientific Assembly, 28 Janu-ary – 4 February 2021, Sydney, Australia, D3.2-0017-21, 2521
- Тезисы
- Год издания: 2021
- Место издания: COSPAR-2021 Sydney, Australia,
- Первая страница: D3.2-0017-21
- Последняя страница: D3.2-0017-21
- Номер статьи: 25211
- Аннотация: We used data of the auroral particle precipitations measured by the DMSP satellite mission to obtain the plasma pressure profiles for different MLT sectors before, during, and after geomag-netic storms and isolated geomagnetic substorms and compare them with the plasma pressure measured in situ by the THEMIS mission satellites. In case of geomagnetic storms, it was found that the plasma pressure strongly increases during the main phase of the storm, and its maxi-mum moves towards the Earth, reaching the closest distance during the Dst minimum. In case of substorms, it was found that the pressure profiles become steeper before the onset and during the expansion phase of substorm, and the value of pressure also increases. The analysis of the corresponding solar wind data showed that for both storms and substorms these increases are correlated with the increases in the solar wind dynamic pressure. Conservation of the plasma pressure along magnetic and current lines in magnetostatic equilibrium, allows the use of the pressure as a “natural tracer” to map one region into another. Using this technique, we conclude that most of the auroral oval is mapped to the cut-ring current (CRC) region, thereby explaining the ring-like shape of the auroral oval. In this approach, the outer ring current is the region where transverse magnetospheric currents close inside the magnetosphere. In particular, it was found that the maximum of the plasma pressure and the most equatorial part of the westward auroral electrojet are located at the same L-shell as the seed population of electrons. Later, this leads to the formation of a new radiation belt at this location. The appearance of relativistic electrons is found to be related to the presence of substorms during a geomagnetic storm recovery phase. We show that these electrons may be accelerated adiabatically by more than one or-der of magnitude.
- Добавил в систему: Антонова Елизавета Евгеньевна