HR: 1340h
AN: SM23A-1184    [Abstracts]
TI: The relationship between high- and low-latitude Pi2 pulsations simultaneously observed by DE-1, AMPTE/CCE, and ground stations
AU: * Teramoto, M
AF: Department of Geophysics, Graduate School of Science, Kyoto University, Kitashirakawa-Oiwakechou,Sakyou-ku, Kyoto, 606-8502, Japan
AU: Nose, M
AF: ata Analysis Center for Geomagnetism and Space Magnetism Graduate School of Science, Kyoto University, Kitashirakawa-Oiwakechou,Sakyou-ku, Kyoto, 606-8502, Japan
AU: Takahashi, K
AF: Johns Hopkins University Applied Physics Laboratory, 11100 Johns Hopkins Road, Laurel, MD 20723-6099, United States
AU: Sutcliffe, P R
AF: Hermanus Magnetic Observatory, Hermanus, South Africa, P. O. Box 32 Hermanus 7200, Republic of South Africa, Hermanus, 7200, South Africa
AU: Sutcliffe, P R
AF: School of Physics, University of KwaZulu-Natal, South Africa, School of Pure and Applied Physics, University of KwaZulu-Natal, Durban, 4041, South Africa
AB: Pi2 pulsations (period from 40s to 150s) are observed at substorm onset. Cavity mode resonance is the possible scenario of low-latitude Pi2 pulsations. It is an open question whether the resonance boundary, plasmapause, is good reflector or not. We investigated Pi2 pulsations observed simultaneously by the polar orbiting DE-1 satellite (an apogee: about 3.6 Re altitude and a perigee: about 500km altitude), equatorial orbiting AMPTE/CCE satellite (an apogee: about 8.8 Re altitude and a perigee: about 1100km altitude), and ground stations at 1132-1136 UT on November 14, 1986. DE-1 was located at polar region (Geomagnetic latitude=-83.42 degrees). AMPTE/CCE was located at L=4.57 and 23.6 MLT. AMPTE/CCE might be located outside the plasmasphere. They are observed Pi2 pulsations in the compressional component. The AL index began to decrease at 1114 UT. It showed substorm onset. They had high coherence with that observed at Kakioka (KAK) in the H component, which was located at L=1.25 and 3.21 MLT. The phase difference between KAK and DE-1 and between KAK and AMPTE/CCE were 180 and 90 degrees at 14 mHz. These Pi2 pulsations had high coherence with that observed by Hermanus (HER), which was located at L=1.8 and 12.8 MLT. These observational results may support that the plasmapause is imperfect boundary. Pi2 pulsations at low latitude are excited by the plasmaspheric virtual resonance mode, in which the ambient magnetic fields outside plasmasphere oscillated with the cavity mode resonance. And Pi2 pulsations at the polar cap are also excited by PVR mode. In this presentation, we will show these Pi2 pulsations observed by DE-1, AMPTE/CCE, HER and KAK, in addition to other ground stations (Port Aux Francais, Furstenfeldbruck, and Wingst) and conduct statistical study of Pi2 pulsations, which were simultaneously observed by the DE-1 and AMPTE/CCE satellite.
DE: 2700 MAGNETOSPHERIC PHYSICS (6939)
DE: 2752 MHD waves and instabilities (2149, 6050, 7836)
DE: 2768 Plasmasphere
DE: 2776 Polar cap phenomena
DE: 2790 Substorms
SC: SPA-Magnetospheric Physics [SM]
MN: 2007 Fall Meeting