HR: 0830h
AN: SH31A-1089    [PDF]
TI: Current Layer Jump Conditions for the Magnetopause
AU: * Steinhauer, L C
EM: steinhauer@aa.washington.edu,lstein@u.washington.edu
AF: Redmond Plasma Physics Laboratory, University of Washington, 14700 NE 95th St., Redmond, WA 98052 United States
AU: McCarthy, M P
EM: mccarthy@geophys.washington.edu
AF: Earth and Space Sciences Department, University of Washington, PO Box 351310, Seattle, WA 98195 United States
AU: Whipple, E C
EM: whipple@geophys.washington.edu
AF: Earth and Space Sciences Department, University of Washington, PO Box 351310, Seattle, WA 98195 United States
AB: Reconnection theory has focused primarily on the elusive x-point or the structure of the current sheet. However the gross properties of reconnection can be determined without probing the internal details of the current sheet: in particular, the energization of particles, the direction and speed of their ejection, the self-consistent magnetic field angle, and the densities of the incident and ejected plasma streams. This can be done with a technique from fluid mechanics, the use of jump conditions such as the familiar Rankine-Hugoniot equations. The magnetopause departs from a simple fluid boundary in that the interaction of the plasma particles with the current sheet produces a highly anisotropic plasma state: particles drift inward in nearly the normal direction; once ejected they move at relatively high speed in nearly the tangential direction. In contrast to the usual jump conditions across a boundary, our analysis considers changes in macroscopic quantities on one side of the current layer boundary as the incident population becomes the ejected population. By incorporating results from studies of the particle equations of motion into conservation laws and Maxwell's equations, new jump conditions for the tangential component of momentum, the out-of-plane component of current density, and energy (Poynting's theorem) are derived. Modest simplifications on the magnetic and electric field structure are assumed, but the fields are quite general otherwise.
DE: 2724 Magnetopause, cusp, and boundary layers
DE: 7835 Magnetic reconnection
SC: SPA - Solar and Heliospheric Physics [SH]
MN: 2003 Fall Meeting