HR: 0830h
AN: SH51A-07    [Abstracts]
TI: Using Total Perpendicular Pressure to Diagnose Stream Interactions
AU: * Jian, L
EM: lanjian@ucla.edu
AF: University of California Los Angeles, Institute of Geophysics & Planetary Physics, 405 Hilgard Ave., Los Angeles, CA 90095-1567 United States
AU: Russell, C T
EM: lanjian@ucla.edu
AF: University of California Los Angeles, Institute of Geophysics & Planetary Physics, 405 Hilgard Ave., Los Angeles, CA 90095-1567 United States
AU: Gosling, J T
EM: jgosling@lanl.gov
AF: Los Alamos National Laboratory, SM-30, Bikini Atoll Rd., Los Alamos, NM 87545 United States
AU: Luhmann, J G
EM: jgluhman@ssl.berkeley.edu
AF: University of California Berkeley, Space Sciences Laboratory, Berkeley, CA 94720-7450 United States
AB: The total perpendicular pressure (thermal plus magnetic) has a very characteristic pattern at the interface between fast and slow streams. The total pressure rises to a maximum at the interface and then decline. This pattern may include sudden changes in pressure at forward and/or reverse shocks. A necessary condition is that the solar wind speed increases through the enhanced pressure region. This aids in the positive identification of the stream interaction. Usually, there are abrupt changes in the plasma properties at the peak in the pressure profile signifying the interface between the two distinct solar wind source regions. The height of the pressure maximum indicates the strength of the interaction. This strength often falls in a narrow range over an extended period of time. Shocks or shock-like jumps in pressure are surprisingly frequent, appearing in about 30 percent of the stream interactions in 1997.
DE: 2100 INTERPLANETARY PHYSICS
DE: 2134 Interplanetary magnetic fields
DE: 2139 Interplanetary shocks
DE: 2164 Solar wind plasma
DE: 7513 Coronal mass ejections
SC: SPA-Solar and Heliospheric Physics [SH]
MN: 2005 Joint Assembly