Subcritical-to-supercritical transition in quasi-perpendicular fast shocks

Thesis/Dissertation · Tue Jan 01 04:00:00 EST 1985

OSTI ID:5319939

Livesey, W A

The magnetic structure of collisionless quasi-perpendicular bow shock waves was observed and studied using fluxgate magnetometer data from the ISEE-1 and 2 spacecraft. The angle theta/sub Bn/ between upstream magnetic field and the shock normal was determined for each case. The fast Mach number M, ..beta../sub i/, and ..beta../sub e/ of the shock waves were estimated using solar wind plasma parameters. The critical fast Mach number M/sub c/, the Mach number for which the downstream flow speed just equals the downstream sound speed, was calculated for each shock using the Rankine-Hugoniot shock jump conditions. A survey of the dependence of various magnetic substructures upon these parameters was performed. A precursor foot to the shock was noted for shock waves characterized by M/M/sub c/ > 1. The thickness of this foot region was in good quantitative agreement with predicted trajectories of solar wind ions undergoing specular reflection from the shock ramp.

• Research Organization: California Univ., Los Angeles (USA)
• OSTI ID: 5319939
• Country of Publication: United States
• Language: English

Related Subjects

640203* -- Atmospheric Physics-- Magnetospheric Phenomena-- (-1987)
71 CLASSICAL AND QUANTUM MECHANICS
GENERAL PHYSICS
EARTH ATMOSPHERE
EARTH MAGNETOSPHERE
EQUATIONS
FLUID FLOW
FLUXGATE MAGNETOMETERS
MACH NUMBER
MAGNETOMETERS
MEASURING INSTRUMENTS
RANKINE-HUGONIOT EQUATIONS
SATELLITES
SHOCK WAVES
SOLAR ACTIVITY
SOLAR WIND
TRANSITION FLOW
VELOCITY