HR: 0800h
AN: SH51C-1231    [Abstracts]
TI: Radial and longitudinal dependence of solar 4-13 MeV and 27-37 MeV proton fluxes and fluences: Helios and IMP-8 observations
AU: * Lario, D
EM: david.lario@jhuapl.edu
AF: Johns Hopkins University Applied Physics Laboratory, 11100 Johns Hopkins Rd., Laurel, MD 20723 United States
AU: Decker, R B
EM: rob.decker@jhuapl.edu
AF: Johns Hopkins University Applied Physics Laboratory, 11100 Johns Hopkins Rd., Laurel, MD 20723 United States
AB: We study the radial and longitudinal dependence of the 4-13 MeV and 27-37 MeV proton peak intensities and fluences measured during intense solar energetic particle events of the solar cycle 21 by the Interplanetary Monitoring Platform-8 and the Helios 1 and 2 spacecraft. Simultaneous measurements of individual events by these three spacecraft show that the dominant parameter that determines the peak intensity and fluence is the longitudinal distance between the parent active region and the footpoint of the magnetic field line that connects each observer with the Sun. The observations do not support the radial dependences of peak fluxes and fluences predicted by the spherically symmetric diffusion transport equation (i.e., R^-3 and R^-2 for peak fluxes and fluences, respectively). The use of these radial dependences overestimates the fluxes and fluences measured at distances R<1 AU.
DE: 7513 Coronal mass ejections (2101)
DE: 7514 Energetic particles (2114)
DE: 7536 Solar activity cycle (2162)
SC: SPA-Solar and Heliospheric Physics [SH]
MN: Fall Meeting 2005