HR: 17:05h
AN: SM24A-04    [Abstracts]
TI: Comparison of EUV Brightness With Line-of-Sight Total Electron Content in the Earth's Plasmasphere.
AU: * Galvan, D A
EM: dgalvan@ucla.edu
AF: Institute of Geophysics and Planetary Physics, University of California, Los Angeles, 405 Hilgard Avenue, Los Angeles, CA 90095-1567, United States
AU: Yizengaw, E
EM: ekassie@igpp.ucla.edu
AF: Institute of Geophysics and Planetary Physics, University of California, Los Angeles, 405 Hilgard Avenue, Los Angeles, CA 90095-1567, United States
AU: Moldwin, M B
EM: mmoldwin@igpp.ucla.edu
AF: Institute of Geophysics and Planetary Physics, University of California, Los Angeles, 405 Hilgard Avenue, Los Angeles, CA 90095-1567, United States
AU: Hajj, G
EM: george.hajj@jpl.nasa.gov
AF: NASA Jet Propulsion Laboratory, 4800 Oak Grove Drive, Pasadena, CA 91109, United States
AU: Mannucci, T
EM: Tony.Mannucci@jpl.nasa.gov
AF: NASA Jet Propulsion Laboratory, 4800 Oak Grove Drive, Pasadena, CA 91109, United States
AU: Sandel, B
EM: sandel@arizona.edu
AF: Lunar and Planetary Laboratory, University of Arizona, 1629 E. University Blvd., Tucson, AZ 85721-0092, United States
AB: Total electron content (TEC) data, obtained from radio signals sent between the Jason-1 satellite in low-Earth- orbit (LEO) and global positioning system (GPS) satellites, are inverted using tomography to infer electron density in Jason-1's orbital plane. We then construct column density traces along the lines of sight of an extreme ultraviolet (EUV) image of the He+ population of the plasmasphere, taken by NASA's IMAGE spacecraft. In this way, we produce column integrated electron density (TEC) values aligned with IMAGE's lines of sight. Since singly-ionized helium in the plasmasphere is optically thin, the radiance of an EUV image pixel is proportional to the column-integrated density of He+ ions along the line of sight. Hence, a TEC measurement gives us a column-integrated electron density, while an EUV image brightness value is proportional to a column-integrated He+ density. By comparing the radial brightness profile from an EUV image to the line-of-sight TEC in Jason's orbital plane, we can gain insight into the behavior of He+ and electron density in the plasmasphere. Future comparisons between TEC and EUV data could lead to an improved, three-dimensional, empirical model of plasmaspheric electron density, and a better understanding of IMAGE EUV images themselves.
DE: 2730 Magnetosphere: inner
DE: 2740 Magnetospheric configuration and dynamics
DE: 2768 Plasmasphere
DE: 2794 Instruments and techniques
SC: SPA-Magnetospheric Physics [SM]
MN: 2007 Joint Assembly