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A note on the location of the stagnation point in the magnetosheath flow
Author(s) -
Russell C. T.,
Zhuang HC.,
Walker R. J.,
Crooker Nancy U.
Publication year - 1981
Publication title -
geophysical research letters
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 2.007
H-Index - 273
eISSN - 1944-8007
pISSN - 0094-8276
DOI - 10.1029/gl008i009p00984
Subject(s) - magnetosheath , physics , magnetosphere , magnetopause , solar wind , magnetohydrodynamics , mach number , stagnation point , geophysics , noon , bow shock (aerodynamics) , mechanics , earth's magnetic field , magnetic field , atmospheric sciences , shock wave , heat transfer , quantum mechanics
Observational and theoretical investigations indicate that the shape of the magnetosphere is nearly symmetric about the plane defined by the aberrated solar wind velocity and the earth's magnetic dipole axis. Nevertheless, many phenomena such as magnetic pulsations and geomagnetic activity seem to indicate that the effective solar wind arrival direction is perhaps 15° to the dawn side of noon. This apparent paradox may have a simple resolution since it can be shown that the location of the stagnation point in the magnetosheath flow is shifted towards dawn by MHD effects not included in the simple gasdynamic model of the solar wind interaction. The shape of the magnetosphere is little affected by the inclusion of these MHD effects. However, the size of the stagnation point shift is very sensitive to the Alfven Mach number and can only account for the largest reported shifts (∼15°) at low Mach numbers (≲3.5).