HR: 1330h
AN: SM13A-01    [Abstracts]
TI: Using Pickup Ions to Determine the Solar Wind Speed at the Cassini Spacecraft
AU: * Hill, M E
EM: mehill@umd.edu
AF: Department of Physics, University of Maryland, College Park, MD 20742-4111 United States
AU: Hamilton, D C
AF: Department of Physics, University of Maryland, College Park, MD 20742-4111 United States
AU: Gloeckler, G
AF: Department of Physics, University of Maryland, College Park, MD 20742-4111 United States
AU: Krimigis, S M
AF: Applied Physics Laboratory, Johns Hopkins University, Laurel, MD 20723 United States
AU: Mitchell, D G
AF: Applied Physics Laboratory, Johns Hopkins University, Laurel, MD 20723 United States
AU: Steinberg, J T
AF: Los Alamos National Laboratory, LANL, Los Alamos, NM 87545 United States
AU: Crary, F J
AF: Southwest Research Institute, SwRI, San Antonio, TX 78228 United States
AB: We calculate solar wind speeds at the Cassini spacecraft when it's in the solar wind, as it was during the cruise to Saturn and as it is for a substantial portion of its orbits around Saturn. This benefits magnetospheric studies by providing a key measure of the upstream conditions. Similarly, a solar wind speed monitor at 9 AU (and during the 2000--2004 cruise phase between 1 and 9 AU) facilitates interplanetary studies. Since pickup ions have an intensity peak at twice the solar wind speed, we use the MIMI/CHEMS measurement of 3--220 keV/e singly charged He to determine the pickup He spectra and calculate speeds down to one-hour resolution. These speeds agree well with solar wind speeds directly measured by Cassini's CAPS instrument during a month long period in 2004, during which speeds varied from 450 to 600 km/s. Aided by further calibration with CAPS, CHEMS can provide solar wind speeds during the frequent periods when the spacecraft orientation prevents CAPS from making the measurement. We calculate solar wind speeds upstream of Saturn during 2004 and 2005 and compare with global variations of the magnetosphere.
DE: 2152 Pickup ions
DE: 2164 Solar wind plasma
DE: 2756 Planetary magnetospheres (5443, 5737, 6030)
DE: 2784 Solar wind/magnetosphere interactions
DE: 6275 Saturn
SC: SPA-Magnetospheric Physics [SM]
MN: 2005 Joint Assembly