Contribution of shock heating and plasma expansion to ion temperatureanisotropy and low frequency wave generation in subsolar magnetosheath

0446622 - ÚFA 2016 CZ eng A - Abstract
Souček, Jan - Escoubet, C. P. - Grison, Benjamin
Contribution of shock heating and plasma expansion to ion temperatureanisotropy and low frequency wave generation in subsolar magnetosheath.
26th IUGG General Assembly 2015. Earth and Environmental Sciences for Future Generations : abstracts. Prague: International Union of Geodesy and Geophysics, 2015. A33p-014.
[Earth and Environmental Sciences for Future Generations. General Assembly of International Union of Geodesy and Geophysics /26./. 22.06.2015-02.07.2015, Prague]
Institutional support: RVO:68378289
Keywords : plasma * ion temperature anisotropy * heliosphere
Subject RIV: DG - Athmosphere Sciences, Meteorology
http://www.iugg2015prague.com/abstractcd/data/HtmlApp/main.html#

We investigated the anisotropic heating of plasma in the subsolar magnetosheath, comparing the relative importance of the two dominant effects contributing to the formation of ion temperature anisotropy. Behind the bow shock, the anisotropy is largely determined by anisotropic Rankine-Hugoniot conditions, while close to the magnetopause, adiabatic expansion becomes the driving effect. We use data from multiple Cluster passes through the narrow subsolar magnetosheath to investigate the profiles of plasma parameters and occurrence and properties of ULF waves. Tracing the plasma flow from the spacecraft location back to the bow shock suggests that the ion temperature anisotropy depends strongly on the local shock parameters (such asm Mach number and the angle between shock normal and upstream magnetic field) even relatively deep in the magnetosheath. Mirror mode structures are very characteristic for this region, appearing immediately after shock crossing, while Alfvèn-ion-cyclotron waves are found in plasma depletion layer. We also analyzed the dependence of the studied subsolar magnetosheath properties on IMF Bz orientation and other solar wind parameters.
Permanent Link: http://hdl.handle.net/11104/0248904