HR: 0830h
AN: SH21B-0116    [PDF]
TI: Cosmic Ray Steady-State Anisotropy Derived From "Spaceship Earth" Observations
AU: * Shalchi, A
EM: andreasm4@yahoo.com
AF: Bartol Research Institute, University of Delaware, 217 Sharp Lab, Newark, DE 19716 United States
AU: Bieber, J W
EM: john@bartol.udel.edu
AF: Bartol Research Institute, University of Delaware, 217 Sharp Lab, Newark, DE 19716 United States
AU: Evenson, P
EM: penguin@bartol.udel.edu
AF: Bartol Research Institute, University of Delaware, 217 Sharp Lab, Newark, DE 19716 United States
AU: Pyle, R
EM: pyle@bartol.udel.edu
AF: Bartol Research Institute, University of Delaware, 217 Sharp Lab, Newark, DE 19716 United States
AB: By analyzing data from a network of high-latitude neutron monitors,it is possible to derive the cosmic ray angular distribution with greater accuracy and much better time resolution than with the traditional method of analyzing diurnal variations observed by a single monitor. We report a new analysis of the cosmic ray steady-state anisotropy using the 11-station "Spaceship Earth" network (and subsets thereof in years before the full network was operational). From these measurements we extract detailed new information on radial and latitudinal gradients of cosmic ray density and the cosmic ray scattering mean free path near Earth. The anisotropy and its variation with the 11-year sunspot cycle and 22-year solar magnetic cycle provide a vital observational basis for testing theories of cosmic ray scattering and for understanding effects of drift and magnetic helicity in the solar modulation of Galactic cosmic rays. Supported by NSF grant ATM-0000315.
DE: 2104 Cosmic rays
DE: 2114 Energetic particles, heliospheric (7514)
DE: 2162 Solar cycle variations (7536)
DE: 7859 Transport processes
SC: SPA - Solar and Heliospheric Physics [SH]
MN: 2003 Fall Meeting