Storm-Time Magnetopause: Pressure Balance

0569030 - ÚFA 2023 RIV US eng J - Journal Article
Grygorov, K. - Němeček, Z. - Šafránková, J. - Šimůnek, Jiří - Gutynska, O.
Storm-Time Magnetopause: Pressure Balance.
Journal of Geophysical Research-Space Physics. Roč. 127, č. 11 (2022), č. článku e2022JA030803. ISSN 2169-9380. E-ISSN 2169-9402
Institutional support: RVO:68378289
Keywords : magnetopause * boundary layer * solar wind * pressure balance * geomagnetic storms
OECD category: Fluids and plasma physics (including surface physics)
Impact factor: 2.8, year: 2022
Method of publishing: Limited access
https://agupubs.onlinelibrary.wiley.com/doi/10.1029/2022JA030803

The magnetopause is treated as a boundary where the pressure of the incoming solar wind is balanced by the pressure of the geomagnetic field and the plasma pressure inside the magnetopause is often neglected. However, published studies of pressure balance at the magnetopause reveal an excess of the magnetosheath pressure. Moreover, our survey of about 50,000 THEMIS magnetopause crossings shows that about 1% of them exhibits even larger magnetic field in the magnetosheath than in the magnetosphere. A subsequent analysis of crossings observed in the subsolar region under a southward interplanetary magnetic field shows the pressure of the dense cold ion population as an important component of the total magnetospheric pressure. This component is too cold to be registered by standard ion analyzers but its density can reach 300 cm(-3). The second effect connected with a presence of cold plasma population is a reduction of the reconnection rate that slows down the transport of the magnetic flux down the tail and leads to magnetic pile-up in the subsolar magnetosheath.
Permanent Link: https://hdl.handle.net/11104/0340334