HR: 0830h
AN: SH11D-1147    [PDF]
TI: Correlating Solar Wind Type as Determined by Genesis with Solar Wind Composition as Observed by ACE
AU: Reisenfeld, D B
EM: dreisen@lanl.gov
AF: Los Alamos National Laboratory, Space and Atmospheric Sciences, MS-D466, Los Alamos, NM 87545 United States
AU: * Barraclough, B L
EM: bbarraclough@lanl.gov
AF: Los Alamos National Laboratory, Space and Atmospheric Sciences, MS-D466, Los Alamos, NM 87545 United States
AU: Dors, E E
EM: edors@lanl.gov
AF: Los Alamos National Laboratory, Space and Atmospheric Sciences, MS-D466, Los Alamos, NM 87545 United States
AU: Steinberg, J T
EM: jsteinberg@lanl.gov
AF: Los Alamos National Laboratory, Space and Atmospheric Sciences, MS-D466, Los Alamos, NM 87545 United States
AU: Wiens, R C
EM: rwiens@lanl.gov
AF: Los Alamos National Laboratory, Space and Atmospheric Sciences, MS-D466, Los Alamos, NM 87545 United States
AU: Neugebauer, M
EM: mneugeb@cox.net
AF: University of Arizona, Lunar and Planetary Laboratory, Bldg. 92, Tucson, AZ 85721 United States
AU: Zurbuchen, T
EM: thomasz@umich.edu
AF: University of Michigan, Dept. AO\&SS, 2455 Hayward St., Ann Arbor, MI 48109 United States
AB: The NASA Genesis spacecraft was launched in August 2001 with the primary operational goal of collecting pristine samples of the solar wind (SW) in ultrapure materials and returning these samples to Earth in 2004 for precision elemental and isotopic analysis in ground-based laboratories. It is well known that there can be compositional variations in the solar wind, depending on the origin of the plasma flows. What is not certain is if there are also isotopic variations that can be tied to flow type. To help resolve this question, Genesis has three SW regime-specific collectors that are either shielded or exposed to the SW flow, depending on the type of wind flowing past the spacecraft. The three SW regimes the different collectors sample are coronal hole, coronal mass ejection and interstream flows. Changes in the SW regime are autonomously determined in real-time using plasma parameters (proton speed and temperature, helium abundance and counterstreaming electron signatures) obtained from plasma ion and electron spectrometers onboard the spacecraft, and the collectors are then deployed accordingly. The question we wish to address in this talk is: do the solar wind regime determinations based on plasma parameters correlate with distinct variations in SW elemental abundances? The answer to the question of whether there are isotopic variations among the different SW regimes will have to wait for analysis of the SW samples once they are returned to Earth next year. As the Genesis plasma spectrometers were not designed to measure compositional variations in the SW, we will utilize the abundance and charge state measurements for O, Mg, Fe, etc. that have been made by the SWICS instrument on the ACE spacecraft and correlate these with the three SW flow types as determined by Genesis. Attempting a correlation of these two data sets is thought to be valid for a large percentage of the study period as both Genesis and ACE are located near the L1 point and likely sample the same flows. Preliminary analysis of the data suggests that there is no distinct compositional transition that divides the slow and fast SW regimes, and that CME composition is independent of flow speed and most resembles that of the slow solar wind. Further results of our attempts to correlate elemental abundance variations with solar wind regime type will be presented at the meeting.
DE: 2164 Solar wind plasma
DE: 2199 General or miscellaneous
DE: 7899 General or miscellaneous
SC: SPA - Solar and Heliospheric Physics [SH]
MN: 2003 Fall Meeting