HR: 1340h
AN: SM43D-1621    [Abstracts]
TI: Effects of Dipole Tilt Angle on Geomagnetic Activities
AU: * Nowada, M
EM: nowada@jupiter.ss.ncu.edu.tw
AF: Institute of Space Science, National Central University, 300, Jhongda Road, Jhongli, Taoyuan 32001, Taiwan, Jhongli, 300, Taiwan
AU: Shue, J
EM: jhshue@jupiter.ss.ncu.edu.tw
AF: Institute of Space Science, National Central University, 300, Jhongda Road, Jhongli, Taoyuan 32001, Taiwan, Jhongli, 300, Taiwan
AU: Russell, C T
EM: ctrussel@igpp.ucla.edu
AF: Institute of Geophysics and Planetary Physics, University of California, Los Angeles, Box 951567, Los Angeles, CA 90095, USA., Los Angeles, CAL 951567, United States
AB: Relationships between the clock angle of the interplanetary magnetic field (IMF) and each of the AL and AU indices are examined under various Earth's dipole tilt angles using the observational data for a period of 1978 to 1988. This study is performed by correlating the interplanetary magnetic field data obtained from the IMP 8 satellite, the AL and AU indices with the corrected seasonal variations, and the dipole tilt angle. It is found that for any value of the IMF clock angle, the values of AL and AU decrease when the dipole tilt angle becomes larger. It suggests that the geomagnetic activities strongly depend on the dipole tilt angle. Furthermore, our results are consistent with the semiannual variation of the geomagnetic activity and the predicted relationships between the geomagnetic activity, the IMF clock angle, and the dipole tilt angle, derived from the MHD simulation.
DE: 2134 Interplanetary magnetic fields
DE: 2431 Ionosphere/magnetosphere interactions (2736)
DE: 2740 Magnetospheric configuration and dynamics
DE: 2784 Solar wind/magnetosphere interactions
DE: 7924 Forecasting (2722)
SC: SPA-Magnetospheric Physics [SM]
MN: 2007 Fall Meeting