HR: 0800h
AN: SH11B-0262    [Abstracts]
TI: The effects of adiabatic cooling on the rigidity-dependent mean free path of gradual SEP events
AU: * Qin, G
EM: gangqin@gmail.com
AF: Dept. of Physics & Space Sciences Florida Institute of Technology, 150 W University Blvd, Melbourne, FL 32901 United States
AU: Zhang, M
EM: mzhang@pss.fit.edu
AF: Dept. of Physics & Space Sciences Florida Institute of Technology, 150 W University Blvd, Melbourne, FL 32901 United States
AU: Dwyer, J R
EM: dwyer@pss.fit.edu
AF: Dept. of Physics & Space Sciences Florida Institute of Technology, 150 W University Blvd, Melbourne, FL 32901 United States
AB: Solar energetic particles (SEP) experience the effect of adiabatic cooling because of the differential solar wind convection. To study the influence of the adiabatic cooling effect on rigidity, we fit gradual SEP events measured by COSPIN instruments onboard Ulysses spacecraft. We find that the adiabatic energy loss contributes significantly to the interplanetary transport of SEPs, and that the mean free path obtained by fitting energetic particle's transport equation with energy loss is systematically lower than the mean free path without energy loss. We think such adiabatic cooling effect helps to partly correct the mean free path's 'too low' problem discussed by Bieber et al 1994.
DE: 7514 Energetic particles (2114)
DE: 7807 Charged particle motion and acceleration
DE: 7859 Transport processes
SC: SPA-Solar and Heliospheric Physics [SH]
MN: Fall Meeting 2005