Statistical study of wave activity upstream the bow shock
| Autor: | Salohub, Anna, Safrankova, Jana, Nemecek, Zdenek, Pi, Gilbert |
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| Jazyk: | angličtina |
| Rok vydání: | 2023 |
| Zdroj: | XXVIII General Assembly of the International Union of Geodesy and Geophysics (IUGG) |
| Popis: | The location of the foreshock boundary depends on the orientation of the interplanetary magnetic field (IMF). The spatial extent of the region populated by the foreshock waves also depends on the IMF. We performed a systematic statistical study based on wave activity close to bow shock for quasi-parallel and quasi-perpendicular configurations of IMF. We investigate standard deviations of the IMF magnitude, its components, and ion density over 10-minute intervals of ULF fluctuations. Observations from the two THEMIS spacecraft were used during the initial stage of the mission when spacecraft were orbiting along low inclination orbits closely to the upstream bow shock. We determine a new foreshock coordinate system (defined as the angle between the shock normal unit vector and upstream magnetic field and the calculated distance from the spacecraft to bow shock) and investigate spatial distributions and compressibility of the fluctuations observed in front of the bow shock. The preliminary study reveals different behaviors of the compressive and Alfvén-like components of magnetic field fluctuations and a strong dependence of the compressibility of fluctuations on the Alfvénic Mach number of the incoming solar wind. The 28th IUGG General Assembly (IUGG2023) (Berlin 2023) |
| Databáze: | OpenAIRE |
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