HR: 10:30h
AN: SM52A-01    [Abstracts]
TI: Dawn-dusk asymmetry in the northward IMF plasma sheet
AU: * Wing, S
EM: simon.wing@jhuapl.edu
AF: The Johns Hopkins University Applied Physics Laboratory, 11100 Johns Hopkins Road, Laurel, MD 20723
AU: Johnson, J R
EM: jrj@pppl.gov
AF: Princeton University Plasma Physics Laboratory, Forrestal Drive, Princeton, NJ
AU: Newell, P T
EM: patrick.newell@jhuapl.edu
AF: The Johns Hopkins University Applied Physics Laboratory, 11100 Johns Hopkins Road, Laurel, MD 20723
AU: meng, C
EM: ching.meng@jhuapl.edu
AF: The Johns Hopkins University Applied Physics Laboratory, 11100 Johns Hopkins Road, Laurel, MD 20723
AB: During periods of northward IMF, as a result of large influx of the magnetosheath ions, the plasma sheet becomes cold and dense. During these periods, a large number of the plasma sheet ions have two components: hot (magnetospheric origin) and cold (magnetosheath origin). Based on their spectral distributions: one-component Maxwellian, two-component Maxwellian, and kappa (k), the characteristics of the plasma sheet ions were studied with DMSP satellites and a method of inferring plasma sheet ion properties from the ionospheric observations. The cold-component constituent of the two-component ions is hotter in the dawn than the dusk sector, consistent with the in situ studies that suggest that the magnetosheath ion is heated upon its entry along the plasma sheet dawn flank. This temperature asymmetry leads to a dawn-dusk asymmetry in the ion spectral distribution. The cold and hot components are closer together in temperature space, which increases the proportion of ions having (apparent) one-component distribution in the dawn flank while, in the dusk flank, the influx of the magnetosheath ions increase the density of the two-component ions. The dawn-dusk asymmetry in the cold magnetosheath ion profile should help determine the roles of various proposed magnetosheath entry mechanisms.
DE: 2736 Magnetosphere/ionosphere interactions
DE: 2744 Magnetotail
DE: 2748 Magnetotail boundary layers
DE: 2764 Plasma sheet
DE: 2784 Solar wind/magnetosphere interactions
SC: SPA-Magnetospheric Physics [SM]
MN: 2005 Joint Assembly