Interplanetary Magnetic Field B-y Controls the Magnetopause Location

0573095 - ÚFA 2024 RIV US eng J - Journal Article
Nafchi, M. A. - Němec, F. - Pi, G. - Němeček, Z. - Šafránková, J. - Grygorov, K. - Šimůnek, Jiří
Interplanetary Magnetic Field B-y Controls the Magnetopause Location.
Journal of Geophysical Research-Space Physics. Roč. 128, č. 5 (2023), č. článku e2023JA031303. ISSN 2169-9380. E-ISSN 2169-9402
Institutional support: RVO:68378289
Keywords : magnetopause * empirical model * interplanetary magnetic field * imf
OECD category: Fluids and plasma physics (including surface physics)
Impact factor: 2.8, year: 2022
Method of publishing: Open access
https://agupubs.onlinelibrary.wiley.com/doi/10.1029/2023JA031303

We present a statistical study of interplanetary magnetic field (IMF) effects on the magnetopause location based on nearly 15,000 magnetopause crossings identified in the THEMIS A-E, Magion 4, Geotail, and Interball-1 satellite data. In order to exclude the dominant controlling role of the solar wind dynamic pressure, differences between observed and empirical model magnetopause distances are analyzed. We find that the magnetopause distance is significantly controlled by the IMF clock angle, not considered in the used empirical models. Furthermore, during very low Alfven Mach numbers (M-A < 4), IMF B-y component can induce a considerable dawn-dusk asymmetry of the magnetopause shape. The magnetopause distance is found to be larger in the direction of the IMF vector, that is, not only the magnitude but also the orientation of the IMF B-y component is eventually important. The obtained results are qualitatively consistent with a magnetohydrodynamic model run at the Community Coordinated Modeling Center.
Permanent Link: https://hdl.handle.net/11104/0343682