HR: 17:54h
AN: SM44A-10    [Abstracts]
TI: Topology of Plasma Flow: Intertwining of the Dungey and the Vasyliunas Cycles
AU: * Vasyli\=unas, V M
EM: vasyliunas@mps.mpg.de
AF: Max-Planck-Institut für Sonnensystemforschung, Max-Planck-Str. 2, Katlenburg-Lindau, 37191, Germany
AB: The configuration of plasma flow in the magnetospheres and magnetotails of Jupiter and Saturn can be described in terms of two basic patterns: magnetospheric circulation imposed by solar wind flow past an open magnetosphere (the "Dungey cycle") and rotationally driven escape of plasma down the magnetotail (the "Vasyli\=unas cycle"). It is often assumed that return (sunward) flow of plasma in the magnetotail is an essential requirement of the Dungey cycle, and that therefore any observational or theoretical obstacles to return flow imply limitations to the cycle. In fact, the only requirement is return of the magnetic flux, not necessarily of the plasma. Both cycles can be described from a unified viewpoint as topological configurations that combine removal of the plasma with circulation of the magnetic flux. Under certain geometrical conditions, part of the return plasma flow from the nightside X-line of the Dungey cycle can proceed tailward and escape down the magnetotail as part of the plasma outflow in the Vasyli\=unas cycle.
DE: 2740 Magnetospheric configuration and dynamics
DE: 2744 Magnetotail
DE: 2756 Planetary magnetospheres (5443, 5737, 6033)
DE: 2760 Plasma convection (2463)
DE: 2784 Solar wind/magnetosphere interactions
SC: SPA-Magnetospheric Physics [SM]
MN: 2007 Fall Meeting