HR: 16:15h
AN: SA22C-02    [PDF]
TI: F-region Ionospheric Irregularities Observed by ROCSAT-1 in the South Atlantic Anomaly Longitude Sector
AU: * Yeh, H
EM: yeh@jupiter.ss.ncu.edu.tw
AF: National Central University, No. 300, Jung-da Road, Chung-Li, 320 Taiwan
AU: Ho, M
AF: National Central University, No. 300, Jung-da Road, Chung-Li, 320 Taiwan
AU: Su, S
AF: National Central University, No. 300, Jung-da Road, Chung-Li, 320 Taiwan
AU: Heelis, R A
AF: The University of Texas at Dallas, William B. Hanson Center, UTD, Richardson, TX 75803 United States
AU: Huang, C
AF: National Central University, No. 300, Jung-da Road, Chung-Li, 320 Taiwan
AU: Ho, H
AF: National Central University, No. 300, Jung-da Road, Chung-Li, 320 Taiwan
AU: Hun, W
AF: National Central University, No. 300, Jung-da Road, Chung-Li, 320 Taiwan
AU: Fu, C
AF: National Central University, No. 300, Jung-da Road, Chung-Li, 320 Taiwan
AU: Huang, C
AF: National Central University, No. 300, Jung-da Road, Chung-Li, 320 Taiwan
AB: Data from the Ionospheric Plasma and Electrodynamics Instrument (IPEI) onboard ROCSAT-1 during the solar maximum years of 2000 and 2001 are used to investigate the plasma depletion (bubble) structures observed in the South Atlantic magnetic Anomaly (SAA) longitude sector. In this longitude sector, the geomagnetic field exhibits great variations in its magnitude, declination, and geographic latitude of the magnetic equator. With the 35-degree inclination orbit, ROCSAT-1 had the opportunity to travel either nearly along the magnetic equator or approximately along the magnetic meridian. We examine how the occurrence probability of the observed bubbles depends on local time, season, magnetic field configuration, and geomagnetic activity. Furthermore, we perform spectral analyses on the high-resolution ion density and cross-track ion velocities data for some representative passes to investigate how the spectral relationships among the density and velocity components are changing as the bubble structures evolve. Significant results from our analyses of the SAA bubbles are: (1) to confirm the magnetic-field-aligned characteristics of plasma bubbles, (2) to evaluate how important role that the magnetic-field-aligned neutral wind plays in producing the growth and the season of bubble structures, and (3) to verify the existence (absence) of the transitional-scale drift waves in the growing/developed (decaying) bubbles near the magnetic equator.
DE: 2415 Equatorial ionosphere
DE: 2439 Ionospheric irregularities
DE: 2471 Plasma waves and instabilities
DE: 2481 Topside ionosphere
SC: SPA - Aeronomy [SA]
MN: 2003 Fall Meeting