HR: 1330h
AN: SH42A-0477    [PDF]
TI: Interplanetary Shocks in the EarthAŸA›A›ƒ_sAªA›ƒ_zA›s Magnetosheath
AU: * Szabo, A
EM: Adam.Szabo@nasa.gov
AF: NASA Goddard Space Flight Center, Code 696, Greenbelt, MD 20771 United States
AB: Gas dynamic work of Stahara and Spreiter in the late 80AŸA›A›ƒ_sAªA›ƒ_zA›s has suggested that interplanetary (IP) shocks once entering into the magnetosheath, turning into pressure pulses, maintain their original surface geometry to a very good approximation. This work presents WIND, ACE, IMP 8, Geotail and Cluster data observing the same IP shocks in the interplanetary medium and in the EarthAŸA›A›ƒ_sAªA›ƒ_zA›s magnetosheath. Multiple solar wind observations are necessary to approximate the interplanetary geometry of these shocks because they often significantly deviate from simple planarity. A number of cases will be presented where 4-spacecraft time/position and single spacecraft MHD jump condition fit results will be compared. Pressure pulses in the magnetosheath, clearly associated with the IP shocks, could be identified for most shocks analyzed for the time period 1998-2002. However, the magnetosheath signatures of very weak and reverse shocks were often completely washed out. For those shocks that have clearly identifiable signatures in the magnetosheath it is demonstrated that they do not deviate significantly from their interplanetary geometry, unlike directional discontinuities hence it becomes possible to extrapolate more accurately their arrival times and locations at the magnetopause.
DE: 2109 Discontinuities
DE: 2139 Interplanetary shocks
DE: 2154 Planetary bow shocks
DE: 2728 Magnetosheath
DE: 2784 Solar wind/magnetosphere interactions
SC: SPA - Solar and Heliospheric Physics [SH]
MN: 2003 Fall Meeting