HR: 1340h
AN: SM13A-0327    [Abstracts]
TI: Impact of the IMF rotation on the cusp dynamics on the dayside: Global 3D PIC simulations
AU: * Tao, W
EM: twf@aoi3.cs.tsukuba.ac.jp
AF: University of Tsukuba, CS, Tsukuba, 305-8573 Japan
AU: Cai, D
EM: cai@is.tsukuba.ac.jp
AF: University of Tsukuba, CS, Tsukuba, 305-8573 Japan
AU: Lembege, B
EM: lembege@cetp.ipsl.fr
AF: IPSL, l'Europe, Velizy, FR-78140 France
AU: Nishikawa, K
EM: ken-Ichi.Nishikawa@nsstc.nasa.gov
AF: National Space Science and Technology Center, 320 Sparkman Drive, Huntsville, AL 35805 United States
AB: The dynamics of the cusp region as the interplanetary magnetic field (IMF) progressively changes its direction from northward to duskward is analysed with a new version of a global three-dimensional full particle simulation. For northward IMF, bands of weak magnetic field (sash) form poleward of the cusp at high latitudes in each hemisphere (and at high altitudes); these sashs are centered approximately around the pole axis. However, as the newly duskward-oriented IMF approaches and interacts with the magnetosphere, these sashs move to the equator (within opposite quadrants). During the progressive rotation of the IMF, this motion is decomposed in the plane perpendicular to the solar wind as follows: (i) the "sash" region widens towards lower latitudes ("banana-shape"), and (ii) the size of the "banana-shape" region strongly shrinks and its location stabilizes around a maximum deviation of 45?. In addition, this motion is observed both on the day and the night sides where sashs are simultaneously observed. Characteristic time and space scales of the cusp motion are indicated, in order to be compare with results deduced from previous MHD simulations. Changes of local reconnection in the cusp region are analysed.
DE: 2723 Magnetic reconnection (7526, 7835)
DE: 2753 Numerical modeling
DE: 2784 Solar wind/magnetosphere interactions
DE: 2790 Substorms
SC: SPA-Magnetospheric Physics [SM]
MN: Fall Meeting 2005