HR: 1340h
AN: SM33A-1252    [Abstracts]
TI: Magnetic field disturbances in the Jovian magnetosphere due to large dynamic pressure enhancements in the solar wind
AU: * Tao, C
EM: tao@pat.geophys.tohoku.ac.jp
AF: Department of Geophysics, Tohoku University, Aramaki-aoba, Sendai, 980-8578 Japan
AU: Kataoka, R
EM: ryuho@nict.go.jp
AF: Applied Research and Standards Department, National Institute of Information and Communications Technology, 4-2-1, Nukui-Kitamachi, Koganei, 184-8795 Japan
AU: Fukunishi, H
EM: fuku@pat.geophys.tohoku.ac.jp
AF: Department of Geophysics, Tohoku University, Aramaki-aoba, Sendai, 980-8578 Japan
AU: Takahashi, Y
EM: yukihiro@pat.geophys.tohoku.ac.jp
AF: Department of Geophysics, Tohoku University, Aramaki-aoba, Sendai, 980-8578 Japan
AU: Yokoyama, T
EM: yokoyama.t@eps.s.u-tokyo.ac.jp
AF: Department of Earth and Planetry Sience, University of Tokyo, 7-3-1, Hongo, Bunkyo-ku, 113-0033 Japan
AB: In order to understand the Jovian magnetospheric response to large enhancements of solar wind dynamic pressure, we investigate magnetic field disturbances observed by the Galileo spacecraft located inside the Jovian magnetosphere. A lack of solar wind monitoring just outside the Jovian magnetosphere is complemented by performing one-dimensional magnetohydrodynamic (MHD) simulation. Solar wind data obtained from the Wind and ACE spacecraft in the vicinity of the Earth are used as input parameters of the solar wind simulation. A verification test of simulated solar wind parameters is performed by comparing them with actual solar wind parameters obtained by the Ulysses spacecraft in the vicinity of the Jovian orbit. The estimated error of shock arrival time is <2 days if the acute angle of Jupiter-Sun-Earth is <50§. We select 9 events that meet a criterion of event selection: an increase of solar wind dynamic pressure >0.3 nPa in a few hours at the Jovian orbit. Characteristic changes of magnetic field disturbances are found for all of the 9 events. For 8 of the 9 events, the rectangular waveform with the rotation period of about 10 hours becomes irregular in response to the large dynamic pressure change. Furthermore, it is found that the amplitude of the turbulent magnetic field in the ultra-low frequency (ULF) range of 0.3 - 10 mHz increases simultaneously with and/or after irregular waveform changes, in proportion to the maximum amplitude of solar wind dynamic pressure enhancements.
DE: 7843 Numerical simulation studies
DE: 5737 Magnetospheres (2756)
DE: 2740 Magnetospheric configuration and dynamics
DE: 2756 Planetary magnetospheres (5443, 5737, 6030)
DE: 2784 Solar wind/magnetosphere interactions
SC: SPA-Magnetospheric Physics [SM]
MN: 2004 AGU Fall Meeting