HR: 0800h
AN: SH51C-0278    [Abstracts]
TI: Alpha Particle Heating in the Solar Wind: ACE Observations
AU: * Gary, S P
EM: pgary@lanl.gov
AF: Los Alamos National Laboratory, Mail Stop D466, Los Alamos, NM 87545 United States
AU: Smith, C W
EM: chuck@briaxa.sr.unh.edu
AF: University of New Hampshire, Space Science Center, 39 College Road, Morse Hall, Room 207, Durham, NH 03824 United States
AU: Skoug, R M
EM: rskoug@lanl.gov
AF: Los Alamos National Laboratory, Mail Stop D466, Los Alamos, NM 87545 United States
AB: Alfv\'en-cyclotron fluctuations of successively shorter wavelengths in collisionless plasmas transfer energy via cyclotron resonances to ions of successively larger charge-to-mass ratios. Theories and simulations predict that this interaction leads to $T_{\perp}/T_{\parallel} >$ 1 for each resonant ion species, where the subscripts refer to directions relative to the background magnetic field. Here observations of the solar wind near 1 AU by the plasma and magnetic field instruments on the ACE spacecraft are reported which show the predicted signatures of such wave-ion interactions in the proton and alpha particle anisotropies. These results support the theory that Alfv\'en-cyclotron fluctuations are an important source of heavy ion heating in the corona.
UR: http://nis-www.lanl.gov/~pgary/
DE: 7867 Wave/particle interactions
DE: 2149 MHD waves and turbulence
DE: 2159 Plasma waves and turbulence
DE: 2164 Solar wind plasma
SC: SPA-Solar and Heliospheric Physics [SH]
MN: 2004 AGU Fall Meeting