HR: 14:40h
AN: SM42D-05    [PDF]
TI: Non-uniform precipitation of solar energetic particles across the Earth's polar caps
AU: * Mazur, J E
AF: The Aerospace Corporation, 2350 E. El Segundo Blvd., El Segundo, CA 90245-4691 United States
AU: Blake, J B
AF: The Aerospace Corporation, 2350 E. El Segundo Blvd., El Segundo, CA 90245-4691 United States
AU: Looper, M D
AF: The Aerospace Corporation, 2350 E. El Segundo Blvd., El Segundo, CA 90245-4691 United States
AU: Mason, G M
AF: University of Maryland, Department of Physics, College Park, MD 20742 United States
AU: Mewaldt, R A
AF: California Institute of Technology, Space Radiation Lab 220-47 Downs, Pasadena, CA 91125 United States
AU: Klecker, B
AF: Max Planck Institute for Extraterrestrial Physics, Garching, Munchen, D-85741 Germany
AU: Kanekal, S
AF: Department of Physics, Catholic University of America, College Park, MD 20742 United States
AB: The Earth's magnetic field has a complex influence on the precipitation of solar energetic particles into the atmosphere at high latitudes. Besides the time-dependent cutoff latitude, one often observes large ($>$ factor of 4) changes in the intensity of solar particles particles as a low-altitude satellite traverses the polar caps. These features were first observed in low-Earth orbit and modeled in the 1970's (e.g. Scholer 1972). Factors such as delayed particle access from deep in the magnetotail, favored access to one pole or the other due to the polarity of the interplanetary magnetic field; and quasi-trapping just above the cutoff latitude were thought to play a role. We revisit these phenomena using the high-sensitivity instruments on the SAMPEX satellite at 600km altitude. We will test the previous concepts and models of solar particle access across a wider range of particle rigidity (10's to 100's MV) and with better statistics than has been done in the past. At the meeting we will quantify non-uniform particle illumination in many events from 1992-2003, including the 14-24 April 2002 interval, and discuss its impact on calculations of the solar particle energy deposit into the atmosphere. M. Scholer, J. Geophys. Res. 77, 2762-2769, 1972.
DE: 2716 Energetic particles, precipitating
DE: 2720 Energetic particles, trapped
DE: 2776 Polar cap phenomena
DE: 7514 Energetic particles (2114)
SC: SPA - Magnetospheric Physics [SM]
MN: 2003 Fall Meeting