Magnetic Field Gradient Across the Flank Magnetopause

0549321 - ÚFA 2022 RIV CH eng J - Článek v odborném periodiku
Němeček, Z. - Grygorov, K. - Šafránková, J. - Šimůnek, Jiří - Pi, G.
Magnetic Field Gradient Across the Flank Magnetopause.
Frontiers in Astronomy and Space Sciences. Roč. 8, Nov 17 (2021), č. článku 778234. E-ISSN 2296-987X
Institucionální podpora: RVO:68378289
Klíčová slova: magnetosphere * magnetopause * magnetosheath * pressure balance * magnetic field gradient * inverse gradient * geomagnetic indices
Obor OECD: Fluids and plasma physics (including surface physics)
Impakt faktor: 4.055, rok: 2021
Způsob publikování: Open access
https://www.frontiersin.org/articles/10.3389/fspas.2021.778234/full

Magnetic pressure inside the magnetopause is usually balanced with a sum of thermal plasma and magnetic pressures on the magnetosheath side. However, observations reveal that the magnetosheath magnetic field can be frequently larger than that in the magnetosphere (inverse magnetic field gradient across the magnetopause), and thus, the enhanced pressure from the magnetosheath side seems to be uncompensated. Such events are rare in the subsolar region, but their occurrence rate increases toward flanks. The analysis, based on statistical processing of about 35,000 THEMIS magnetopause crossings collected in the course of the years 2007-2017, shows that these events are more frequently observed under enhanced geomagnetic activity that is connected with a strong southward IMF. Case studies reveal that such a state of the magnetopause boundary layers can persist for several hours. This study discusses conditions and mechanisms keeping the pressure balance across the magnetopause under these conditions.
Trvalý link: http://hdl.handle.net/11104/0325513