HR: 1330h
AN: SA13A-11    [Abstracts]
TI: High speed solar wind streams with and without magnetic storms at Earth
AU: * Kessel, R L
EM: ramona.l.kessel@nasa.gov
AF: NASA GSFC, code 612.4, Greenbelt, MD 20771 United States
AU: Collado-Vega, Y
EM: yaireskal@mail630.gsfc.nasa.gov
AF: NASA GSFC, code 612.4, Greenbelt, MD 20771 United States
AU: Blake, J B
EM: JBernard.Blake@aero.org
AF: aerospace corp, POB 92957, Los Angeles, CA 90009 United States
AB: We show two high speed solar wind streams in April 2002 carrying solar energy flux that with high probability, couple to the Earth's magnetosphere and cause enhanced magnetospheric fluctuations. Many aspects of the two streams are similar and with similar effects at Earth. However there are also significant differences that allow us to differentiate cause and effect in some cases. For the first stream the IMF is primarily northward and Dst at Earth is modest. The second stream has strong southward IMF and large Dst. The first high speed stream is not associated with a large magnetic storm, but strong Pc5 pulsations are observed just inside the magnetopause (dawn, noon, and dusk), in the magnetotail, and at geostationary orbit. The second high speed stream shows strong magnetospheric pulsations and is associated with a large magnetic storm. Enhanced fluxes of energetic particles are observed for both streams, but the second stream with the geomagnetic storm shows fluxes extending across a larger L-shell range. Wind observations, 70-80 R_E upstream from Earth, show significant, sustained power at Pc5 frequencies intrinsic to the high speed stream for both cases. The enhanced power is evident in dynamic pressure fluctuations and to a lesser extent in compressional magnetic field fluctuations. In the Earth's magnetosphere the wave mode depends on the location that the waves are observed. Polodial mode waves are commonly seen on the dawn and dusk flanks of the magnetosphere, but at the nose the compressional component is frequently dominant. In the magnetotail, there are both polodial and torodial modes, but the torodial mode is usually dominant.
DE: 2752 MHD waves and instabilities
DE: 2784 Solar wind/magnetosphere interactions
DE: 2788 Storms and substorms
DE: 7867 Wave/particle interactions
SC: SPA-Aeronomy [SA]
MN: 2005 Joint Assembly