HR: 17:45h
AN: SM44A-08    [Abstracts]
TI: Pi2 Pulsations Observed From the Polar Satellite Outside the Plasmapause
AU: * Kim, K
EM: khan@kasi.re.kr
AF: Korea Astronomy and Space Science Institute, Whaam-Dong,Youseong-Gu, Daejeon, 305-348 Korea, Republic of
AU: Lee, D
EM: dhlee@khu.ac.kr
AF: Department of Astronomy and Space Science, Kyung Hee University, Yongin, Kyunggi, 449-701 Korea, Republic of
AU: Takahashi, K
EM: kazue.takahashi@jhuapl.edu
AF: Johns Hopkins University, Applied Physics Laboratory, 11100 Johns Hopkins Road, Laurel, MD 20723-6099 United States
AU: Russell, C
EM: ctrussell@igpp.ucla.edu
AF: Institute of Geophysics and Planetary Physics, University of California, 405 Hilgard Ave, Los Angeles, CA 90095-156 United States
AU: Moon, Y
EM: yjmoon@kasi.re.kr
AF: Korea Astronomy and Space Science Institute, Whaam-Dong,Youseong-Gu, Daejeon, 305-348 Korea, Republic of
AU: Yumoto, K
EM: yumoto@serc.kyushu-u.ac.jp
AF: Space Environment Research Center, Kyushu University, 53 6-10-1 Hakozaki, Fukuoka, 812-8581 Japan
AB: Recently, Lee and Lysak [1999] suggested that Pi2 pulsations in the inner magnetosphere originate from plasmaspheric virtual resonances (PVR). The PVR model predicts that Pi2 pulsations are not strictly localized to the plasmasphere. Until now there have been no spacecraft observations of the PVR mode outside the plasmasphere. Motivated by the theoretical work, we examine Pi2 pulsations simultaneously observed by the Polar satellite outside the plasmapause and at the low-latitude Kakioka (L = 1.3) station. We identify 14 events to have high coherence (> 0.7) between the compressional component (bz) in space and the horizontal component (H) at Kakioka during a 2-month period in 1997. The H-bz cross phase is ~180° regardless of the satellite's distance from the plasmapause. The amplitude of the Pi2 pulsations tends to decrease with the distance. On the basis of these observations, we conclude that the PVR mode is an appropriate model for our Pi2 events observed outside the plasmasphere.
DE: 2700 MAGNETOSPHERIC PHYSICS (6939)
DE: 2752 MHD waves and instabilities (2149, 6050, 7836)
DE: 2764 Plasma sheet
DE: 2768 Plasmasphere
DE: 2790 Substorms
SC: SPA-Magnetospheric Physics [SM]
MN: Fall Meeting 2005