HR: 0800h
AN: SA21C-0366    [Abstracts]
TI: Coordinated Observation of Large-scale TIDs by SuperDARN and GEONET
AU: * Nishitani, N
EM: nisitani@stelab.nagoya-u.ac.jp
AF: STELAB, Nagoya Univ., 3-13 Honohara, Toyokawa, 442-8507 Japan
AU: Ogawa, T
EM: ogawa@stelab.nagoya-u.ac.jp
AF: STELAB, Nagoya Univ., 3-13 Honohara, Toyokawa, 442-8507 Japan
AU: Kikuchi, T
EM: kikuchi@nict.go.jp
AF: NICT, Nukui-Kita Machi, Koganei, Tokyo, 184-8795 Japan
AU: Tsugawa, T
EM: tsugawa@stelab.nagoya-u.ac.jp
AF: STELAB, Nagoya Univ., 3-13 Honohara, Toyokawa, 442-8507 Japan
AU: Saito, A
EM: saitoua@kugi.kyoto-u.ac.jp
AF: Graduate School of Science, Kyoto Univ., Sakyo-ku, Kyoto, 606-8502 Japan
AU: Otsuka, Y
EM: otsuka@stelab.nagoya-u.ac.jp
AF: STELAB, Nagoya Univ., 3-13 Honohara, Toyokawa, 442-8507 Japan
AU: Bristow, W A
EM: Bill.Bristow@gi.alaska.edu
AF: Geophysical Institute, Univ. of Alaska, 903 Koyukuk Dr., Fairbanks, AK 99775 United States
AU: Sato, N
EM: nsato@nipr.ac.jp
AF: National Institute of Polar Research, 1-9-10 Kaga, Itabashi-ku, Tokyo, 173-8515 Japan
AB: We present results of the multi-event analysis of the relationship between mid-latitude large-scale traveling ionospheric disturbances (LSTIDs) observed by the GPS receiver network in Japan (GEONET), which have a period of 30 to 120 minutes and longer than 1000 km wavelengths, and the high-latitude ionospheric disturbances observed by the SuperDARN radars. Among the mid-latitude LSTID events observed by GEONET between July 2002 and December 2003, we found 5 examples where the Alaskan SuperDARN radars observed enough amounts of ground scatter echoes. For all of these events the radar data showed long-period (1 to 1.5 hours) oscillation in the Doppler velocities, probably corresponding to the vertical oscillation of the ionosphere, about 2-hours prior to the observation of mid-latitude LSTIDs. This is consistent with the general recognition that LSTIDs are ionospheric manifestations of large-scale gravity waves excited by the energy input from the magnetosphere to the auroral ionosphere. The time delays between these high and middle latitude LSTIDs are consistent with the difference in latitude and the observed propagation speed. Detailed discussion on the propagation and damping mechanism of LSTID will be presented.
DE: 2407 Auroral ionosphere (2704)
DE: 2427 Ionosphere/atmosphere interactions (0335)
DE: 2435 Ionospheric disturbances
DE: 2443 Midlatitude ionosphere
DE: 2487 Wave propagation (6934)
SC: SPA-Aeronomy [SA]
MN: 2004 AGU Fall Meeting