Statistical study of influence of ULF waves and their compressibility on the solar wind velocity in the Earth’s foreshock

0503861 - ÚFA 2020 DE eng A - Abstract
Urbář, Jaroslav - Němeček, Z. - Šafránková, J. - Přech, L.
Statistical study of influence of ULF waves and their compressibility on the solar wind velocity in the Earth’s foreshock.
Geophysical Research Abstracts. Vol. 21. Göttingen: European Geosciences Union, 2019. EGU2019-5385.
[EGU General Assembly 2019. 07.04.2019-12.04.2019, Vienna]
Institutional support: RVO:68378289
Keywords : solar wind * foreshock * ultra low frequency (ULF) waves * THEMIS mission
OECD category: Fluids and plasma physics (including surface physics)
https://meetingorganizer.copernicus.org/EGU2019/EGU2019-5385.pdf

The parameters of solar wind (SW) ion populations are modified upstream the Earth’s bow shock, in the ion foreshock region, which is typically observed ahead of the quasi-parallel bow shock. The interaction of the incoming SW with the ions reflected at the bow shock generate ULF waves, among them fast magnetosonic waves with an in-phase relationship between the ion flux and magnetic field fluctuations. Using cautiously selected SW proton population from the THEMIS ion 3D distributions, we present statistical maps of a modification of the SW proton velocity due to foreshock processes. We evaluated both electric and magnetic field fluctuation levels associated with ULF waves and their compressibility. A special attention is devoted to evaluation of a contribution of alpha particles to the proton moments using intervals of the solar wind unaffected by the foreshock processes.
Permanent Link: http://hdl.handle.net/11104/0295632