A new view on drivers of magnetopause locationse

0473476 - ÚFA 2017 FR eng A - Abstrakt
Němeček, Z. - Šafránková, J. - Šimůnek, Jiří - Shue, J.-H. - Samsonov, A. A.
A new view on drivers of magnetopause locationse.
4th Cluster and THEMIS workshop: Book of abstracts. Paris: European Space Agency (ESA), 2017. s. 22-23.
[Cluster-THEMIS Workshop /4./. 07.11.2016-12.11.2016, Palm Springs]
Institucionální podpora: RVO:68378289
Klíčová slova: solar wind * magnetopause * THEMIS spacecraft
Kód oboru RIV: BL - Fyzika plazmatu a výboje v plynech
http://themis.igpp.ucla.edu/events/CLUSTER_THEMIS_2016/Workshop_abstracts_v3.pdf

The solar wind dynamic pressure is the principal factor controlling the
magnetopause location. Their mutual relation is usually considered in a power-law
form and suggested indices vary from -1/4.8 to -1/6.6 in particular magnetopause
models. The paper analyzes about ten thousands of THEMIS dayside magnetopause crossings observed in a broad range of upstream pressures (0.2-20 nPa) and
discusses the relationship between the dynamic pressure and magnetopause standoff
distance and flaring angle. We found that (1) the power-law form provides the
best description of variations of the stand-off distance with upstream pressure for a
full set of crossings as well as for subsets constrained by a sign of the interplanetary
magnetic field (IMF) vertical component, IMF cone angle, and solar wind speed; (2)
the most appropriate value of the power index resulting from the present study is
-1/3.83 if only a dependence on the upstream solar wind pressure is considered;
(3) the power index varies from -1/3.1 to -1/4.2 depending on the IMF direction and
solar wind speed; and (4) the value of the power index increases to or above -1/6 if
the orbital spacecraft limitations are not handled properly.
Trvalý link: http://hdl.handle.net/11104/0270589