The Kelvin-Helmholtz instability at the magnetopause and inner boundary layer surface

Journal Article · Tue Oct 31 23:00:00 EST 1989 · Journal of Geophysical Research; (USA)

DOI:https://doi.org/10.1029/JA094iA11p15113· OSTI ID:6990785

Ogilvie, K W; Fitzenreiter, R J ^[1]

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1. Laboratory for Extraterrestrial Physics, NASA Goddard Space Flight Center, Greenbelt, Maryland (US)

In this paper observations by the vector electron spectrometer on the ISEE 1 spacecraft are used to directly check the incompressible hydrodynamic stability condition given by Hasegawa (1975), which indicates how stability is influenced by the velocity shear, density ratio, magnetic field, and the direction of the wave vector of the unstable wave mode. Since the plasma quantities can be measured, the stability can be examined by means of a contour plot of the stability condition in {theta}, {phi} space, where {theta} is the polar angle and {phi} the azimuthal angle specifying the wave direction assumed. The magnetopause is generally found to be stable, by a large margin. In contrast, many cases of marginal stability or instability are found across density transitions in, and at the inner edge of, the boundary layer for wave vectors in plausible directions. It thus appears that the Kelvin-Helmholtz instability is of importance at the inner edge of the magnetospheric boundary layer, as predicted by magnetohydrodynamic theory. {copyright} American Geophysical Union 1989

• OSTI ID: 6990785
• Journal Information: Journal of Geophysical Research; (USA), Journal Name: Journal of Geophysical Research; (USA) Vol. 94:A11; ISSN JGREA; ISSN 0148-0227
• Country of Publication: United States
• Language: English

Related Subjects

640201* -- Atmospheric Physics-- Auroral
Ionospheric
& Magetospheric Phenomena
71 CLASSICAL AND QUANTUM MECHANICS
GENERAL PHYSICS
BOUNDARY LAYERS
ELECTRON SPECTROMETERS
FLUID MECHANICS
HELMHOLTZ INSTABILITY
HYDRODYNAMICS
INSTABILITY
LAYERS
MAGNETIC FIELDS
MAGNETOHYDRODYNAMICS
MAGNETOPAUSE
MEASURING INSTRUMENTS
MECHANICS
PLASMA INSTABILITY
PLASMA MACROINSTABILITIES
PLASMA WAVES
SPECTROMETERS
VARIATIONS
VELOCITY
WAVE PROPAGATION