HR: 1340h
AN: SH53A-1259    [Abstracts]
TI: Modeling the Acceleration of Solar Wind and Pick-up Ions at Interplanetary Shocks
AU: * Summerlin, E J
EM: xerex@rice.edu
AF: Department of Physics and Astronomy, MS-108, Rice University,P. O. Box 1892, Houston, TX 77251-1892 United States
AU: Baring, M G
EM: baring@rice.edu
AF: Department of Physics and Astronomy, MS-108, Rice University,P. O. Box 1892, Houston, TX 77251-1892 United States
AB: The acceleration of interstellar pick-up ions as well as solar wind species has been observed at a multitude of interplanetary (IP) shocks by different spacecraft. The efficiency of injection of the pick-up ion component differs from that of the solar wind, and is expected to be strongly enhanced at highly oblique and quasi-perpendicular shock events, in accord with inferences from in situ bservations. This paper expands upon previous work modeling the phase space distributions of accelerated ions obtained by the Ulysses mission for the Day 292, 1991 shock associated with a corotating interaction region, encountered before Ulysses's fly-by of Jupiter. In this previous work, a Monte Carlo simulation was used to model the acceleration process, adapting a technique that had been successfully tested on earlier IP shocks possessing minimal pick-up ion presence. This paper will explore the influence of radial variations in the pick-up ion population by modeling Ulysses data from one of these earlier IP shocks, the Day 147, 1991 event, and comparing to results for the Day 292, 1991 shock. In particular, earlier modeling found that with the omission of pick-up ions there existed a significant underproduction of suprathermal ions; here we will determine if the inclusion of this extra component can resolve this discrepancy. Upstream spatial scales and solar wind fluctuations for the two shocks, and magnetic turbulence parameters constrained by the model fits, will be discussed, aiding in the interpretation of these acceleration environments.
DE: 2139 Interplanetary shocks
DE: 2149 MHD waves and turbulence (2752, 6050, 7836)
DE: 2152 Pickup ions
SC: SPA-Solar and Heliospheric Physics [SH]
MN: Fall Meeting 2005