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Dependence of the magnetopause Kelvin‐Helmholtz instability on the orientation of the magnetosheath magnetic field
Author(s) -
Miura Akira
Publication year - 1995
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 - 10.1029/95gl02793
Subject(s) - magnetopause , magnetosheath , physics , instability , magnetic field , magnetohydrodynamics , geophysics , magnetosphere , field (mathematics) , discontinuity (linguistics) , mechanics , quantum mechanics , mathematical analysis , mathematics , pure mathematics
It is shown by means of a 2‐D MHD simulation that the observed rotation of the unperturbed magnetic field within the magnetopause (MP), which is assumed to be a tangential discontinuity (TD), leads to a significant dependence of the magnetopause Kelvin‐Helmholtz (K‐H) instability on the orientation of the sheath field. That is, northward sheath B z is more favorable to the instability than southward B z and the MP undulates most strongly when the sheath field points due north. When the sheath field does not point due north, a slow rarefaction region is formed in the velocity boundary layer (BL) inside the MP, wherein there are minima of the plasma pressure and temperature accompanied by a maximum of the magnetic pressure.