HR: 0800h
AN: SA31A-0345    [Abstracts]
TI: Global Energetic Proton Precipitation During April 2002 and Its Impact on the Ionosphere-Thermosphere System
AU: * Fang, X
EM: xhfang@umich.edu
AF: Space Physics Research Laboratory, University of Michigan, 2455 Hayward Street, Ann Arbor, MI 48109-2143 United States
AU: Liemohn, M W
EM: liemohn@umich.edu
AF: Space Physics Research Laboratory, University of Michigan, 2455 Hayward Street, Ann Arbor, MI 48109-2143 United States
AU: Kozyra, J U
EM: jukozyra@engin.umich.edu
AF: Space Physics Research Laboratory, University of Michigan, 2455 Hayward Street, Ann Arbor, MI 48109-2143 United States
AU: Ridley, A J
EM: ridley@umich.edu
AF: Space Physics Research Laboratory, University of Michigan, 2455 Hayward Street, Ann Arbor, MI 48109-2143 United States
AU: Evans, D S
EM: david.s.evans@noaa.gov
AF: Space Environment Center, National Oceanic and Atmospheric Administration, 325 Broadway, Boulder, CO 80303 United States
AU: Solomon, S C
EM: stans@ucar.edu
AF: High Altitude Observatory, National Center for Atmospheric Research, 3450 Mitchell Lane, Boulder, CO 80301 United States
AB: Global energetic proton precipitation patterns during the 16-18 April 2002 magnetic storm events were generated using newly-developed data products of MEPED instruments onboard the NOAA-15 and -16 satellites. The observational data set was first sorted in 1-degree CML and 8-minute MLT bins. To achieve global coverage, the missing MLT data were then filled by interpolation techniques in each 1-degree CML interval. Four spatial interpolation approaches were carried out and compared: cosine or linear fits to data points or MLT bin averages. The resulting global proton precipitation maps, available on a 3-hour cadence, provide new information on the development and variability in the structure of incident high energy protons on a time scale commensurate with ring current growth and decay. The geoeffectiveness of 30-240 keV proton injection was assessed by running our newly-developed three-dimensional Monte Carlo ion transport model. The global characteristics of the resulting ionization and heating rates are presented. The disturbances resulted from proton precipitation were coupled into a global ionosphere-thermosphere model developed at the University of Michigan. For the first time using in situ particle flux measurements, we can examine on a planetary scale the proton role in the geoeffectiveness of storm-time particle precipitation on the thermosphere-ionosphere system. The times and places where protons significantly contribute to geoeffectiveness are described. The effect of lateral spreading of the precipitating particles is examined and discussed.
DE: 2407 Auroral ionosphere (2704)
DE: 2455 Particle precipitation
DE: 2704 Auroral phenomena (2407)
DE: 2736 Magnetosphere/ionosphere interactions (2431)
DE: 2778 Ring current
SC: SPA-Aeronomy [SA]
MN: Fall Meeting 2005