HR: 17:30h
AN: SH12C-07    [PDF]
TI: Anisotropies of anomalous and galactic cosmic rays upstream and downstream of the termination shock
AU: * Zhang, M
EM: mzhang@pss.fit.edu
AF: Florida Institute of Technology, 150 W. University Blvd. Department of Physics and Space Science, Melbourne, FL 32901 United States
AU: Ball, B
EM: bball@cr1.pss.fit.edu
AF: Florida Institute of Technology, 150 W. University Blvd. Department of Physics and Space Science, Melbourne, FL 32901 United States
AU: Qin, G
EM: gqin@fit.edu
AF: Florida Institute of Technology, 150 W. University Blvd. Department of Physics and Space Science, Melbourne, FL 32901 United States
AU: Rassoul, H
EM: rassoul@pss.fit.edu
AF: Florida Institute of Technology, 150 W. University Blvd. Department of Physics and Space Science, Melbourne, FL 32901 United States
AB: Anisotropies of low-energy anomalous and galactic cosmic rays observed in the heliosphere can come from the Compton-Getting effect, particle diffusion and gyration effect associated with particle density gradient. When the spacecraft is connected to the particle source at the termination shock by magnetic field lines within a few particle mean free paths, particle streaming may also contribute to the anisotropy. A straightforward determination of solar wind speed based on the simple assumption that the anisotropy comes from the Compton-Getting effect may derive an incorrect value. This is particularly true near and upstream the termination shock where the particle gradient could be large enough to yield a diffusive anisotropy that cancels the Compton-Getting effect. In this paper, we present the results of a calculation of anomalous and galactic cosmic ray anisotropy using a heliospheric model that includes the termination shock and a heliosheath. Comparison with recent Voyager observations at 85-89 AU will be discussed. This work was supported in part by NASA Grant NAG5-11036.
DE: 2104 Cosmic rays
DE: 2124 Heliopause and solar wind termination
DE: 2164 Solar wind plasma
SC: SPA - Solar and Heliospheric Physics [SH]
MN: 2003 Fall Meeting