HR: 09:30h
AN: SM41B-07    [Abstracts]
TI: Solar wind pressure as a cause for persistent proton precipitation
AU: * Laundal, K M
EM: laundal@ift.uib.no
AF: Dept. of Physics and Technology - Univ. of Bergen, Norway, Allegaten 55, Bergen, 5007, Norway
AU: Østgaard, N
EM: nikost@ift.uib.no
AF: Dept. of Physics and Technology - Univ. of Bergen, Norway, Allegaten 55, Bergen, 5007, Norway
AB: Recent studies have demonstrated that the intensity of the proton aurora increases at all magnetic local times following a solar wind shock. The proton aurora intensity has been shown to be higher when the shock is preceded by a period with southward IMF, than for northward IMF. The magnitude of the solar wind pressure after the shock is believed to be of minor importance. We use global satellite images to study the proton precipitation in relation to the solar wind dynamic pressure. The study is focused on times when the geomagnetic activity is low, and the majority of the observed aurora unambiguously can be attributed to the solar wind pressure. The new finding in our study is that the intensified nightside proton aurora is persistent, and lasts as long as the pressure is high. When the pressure drops, the proton aurora diminishes within few minutes. The behavior of the electron dominated global aurora during these events will also be investigated.
DE: 2704 Auroral phenomena (2407)
DE: 2716 Energetic particles: precipitating
DE: 2784 Solar wind/magnetosphere interactions
SC: SPA-Magnetospheric Physics [SM]
MN: 2007 Fall Meeting