HR: 0830h
AN: SM31B-1113    [PDF]
TI: How does the solar wind power the magnetosphere during geoeffective high speed streams?
AU: * Kessel, R L
EM: Ramona.L.Kessel@nasa.gov
AF: NASA Goddard Space Flight Center, code 632, Greenbelt, MD 20771 United States
AU: Shao, X
EM: shao@mail630.gsfc.nasa.gov
AF: NASA Goddard Space Flight Center, code 632, Greenbelt, MD 20771 United States
AU: Collado-Vega, Y
EM: yaireska@mail630.gsfc.nasa.gov
AF: NASA Goddard Space Flight Center, code 632, Greenbelt, MD 20771 United States
AB: We compare and contrast two mechanisms explaining the source of enhanced Pc5 energy in the magnetosphere during the high speed stream beginning 30 March 2002. In the first mechanism fast solar wind streams lead to an enhanced Kelvin-Helmholtz (K-H) instability on the magnetopause flanks causing enhanced Pc5 power inside the magnetosphere. In the second mechanism compressional fluctuations intinsic to the solar wind drive Pc5 power in the magnetosphere, either directly at the same frequencies or indirectly where the input frequencies are broadband and cause random boundary motion that excites magnetospheric cavity eigenfrequencies. We use observations from ACE and Wind to show the power intrinsic to the solar wind. Geotail and Cluster, at the magnetopause, together with MHD simulations highlight the K-H instability. GOES data and ground-based data from the SAMNET, IMAGE, or SAMNET arrays are used to show the magnetospheric response. We compare the wave frequencies in all regions focusing particularly on the existence of cavity eigenfrequencies. Results from these analyses will be presented.
DE: 2149 MHD waves and turbulence
DE: 2724 Magnetopause, cusp, and boundary layers
DE: 2752 MHD waves and instabilities
DE: 2784 Solar wind/magnetosphere interactions
SC: SPA - Magnetospheric Physics [SM]
MN: 2003 Fall Meeting