HR: 17:30h
AN: SA14A-07    [Abstracts]
TI: A Comprehensive Analysis of Ionospheric Variations Associated With the Sumatra Earthquake on December 26, 2004
AU: * Shinagawa, H
EM: sinagawa@nict.go.jp
AF: National Institute of Information and Communications Technology, 4-2-1 Nukui-Kitamachi, Koganei, Tokyo, 184-8795 Japan
AU: Iyemori, T
EM: iyemori@kugi.kyoto-u.ac.jp
AF: Kyoto University, Kitashirakawa Oiwake-cho, Kyoto, 606-8502 Japan
AU: Nose, M
EM: nose@kugi.kyoto-u.ac.jp
AF: Kyoto University, Kitashirakawa Oiwake-cho, Kyoto, 606-8502 Japan
AU: Hashizume, M
EM: hashmich@geo.sc.chula.ac.th
AF: Chulalongkorn University, 254 Phyathai Road, Patumwan, Bangkok, 10330 Thailand
AU: Gao, Y
EM: yufen_gaoliu@bbn.cn
AF: Institute of Geophysics, China Earthquake Administration, P.O.8116, Beijing, 100081 China
AU: Han, D
EM: nmhan@hotmail.com
AF: Kyoto University, Kitashirakawa Oiwake-cho, Kyoto, 606-8502 Japan
AU: Tanaka, Y
EM: tanaka@aso.vgs.kyoto-u.ac.jp
AF: Kyoto University, Kitashirakawa Oiwake-cho, Kyoto, 606-8502 Japan
AU: Otsuka, Y
EM: otsuka@stelab.nagoya-u.ac.jp
AF: STEL, Nagoya University, 3-13 Honohara, Toyokawa, 442-8507 Japan
AU: Effendy, A
EM: defendy@plasa.com
AF: National Institute for Aeronautics and Space, jl. Dr. Junjunan No. 133, Bandung, 40173 Indonesia
AU: Maruyama, T
EM: tmaru@nict.go.jp
AF: National Institute of Information and Communications Technology, 4-2-1 Nukui-Kitamachi, Koganei, Tokyo, 184-8795 Japan
AU: Saito, S
EM: susaito@nict.go.jp
AF: National Institute of Information and Communications Technology, 4-2-1 Nukui-Kitamachi, Koganei, Tokyo, 184-8795 Japan
AU: Kawamura, M
EM: kawamura@nict.go.jp
AF: National Institute of Information and Communications Technology, 4-2-1 Nukui-Kitamachi, Koganei, Tokyo, 184-8795 Japan
AB: There have been a number of reports that some of ionospheric variations originate from lower atmospheric disturbances. However, few direct relationships between lower atmospheric disturbances and ionospheric variations have been found. In the Sumatra earthquake on December 26, 2004, significant ionospheric variations were detected by various instruments just after the earthquake. A magnetic pulsation with a period of about 3.6 minutes was observed at Phimai (15.2N, 102.6E), Thailand about 10 minutes after the earthquake. The localized nature and oscillation period indicate that the magnetic pulsation is likely to be generated through a dynamo in the ionosphere caused by acoustic duct resonance between the sea surface and the bottom of the thermosphere. Traveling ionospheric disturbances (TIDs) were also detected by GPS/TEC and ionosonde observations at various locations after the earthquake. We have examined this event using observational data as well as a two-dimensional nonhydrostatic compressible atmosphere-ionosphere coupling model. A preliminary result of the numerical simulation implies that atmospheric oscillation with a period of 4 minutes is generated in the thermosphere, and that TIDs with a period of a few tens of minutes and a phase speed of several hundreds of m/s are produced. We discuss the mechanism of the ionospheric perturbations caused by the earthquake.
DE: 2427 Ionosphere/atmosphere interactions (0335)
DE: 2435 Ionospheric disturbances
DE: 3384 Acoustic-gravity waves
DE: 4564 Tsunamis and storm surges
DE: 9800 GENERAL OR MISCELLANEOUS
SC: SPA-Aeronomy [SA]
MN: Fall Meeting 2005