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Title: Solar wind electrons: Parametric constraints

Abstract

Solar wind electrons are often observed to consist of two distinguishable components, a thermal, more dense core and a suprathermal, less dense halo. In this core/halo model linear Vlasov theory for the whistler heat flux instability predicts dimensionless heat flux thresholds which decrease as the electron core beta, {tilde {beta}}{sub {parallel}c}, increases. It has been proposed that this theoretical threshold corresponds to an observable upper bound on the electron heat flux. Linear theory also predicts that there is a critical value of {tilde {beta}}{sub {parallel}c} below which the whistler heat flux instability does not have appreciable growth in the solar wind; there is another suggestion that this corresponds to an observable lower bound on {tilde {beta}}{sub {parallel}c}. These two proposals are examined by comparison of linear theory and data from the initial in-ecliptic phase of the Ulysses mission. The instability threshold does provide a statistical constraint on observed solar wind heat fluxes, and the critical {tilde {beta}}{sub {parallel}c} of theory is not inconsistent with a statistical lower bound on the observations of that parameter. {copyright} 1999 American Geophysical Union

Authors:
; ;  [1];  [2]
  1. Los Alamos National Laboratory, Los Alamos, New Mexico (United States)
  2. Jet Propulsion Laboratory, Pasadena, California (United States)
Publication Date:
OSTI Identifier:
688001
Resource Type:
Journal Article
Journal Name:
Journal of Geophysical Research
Additional Journal Information:
Journal Volume: 104; Journal Issue: A9; Other Information: PBD: Sep 1999
Country of Publication:
United States
Language:
English
Subject:
66 PHYSICS; SOLAR WIND; WHISTLERS; HEAT TRANSFER; INTERPLANETARY SPACE; SOLAR WATER HEATERS; PLASMA INSTABILITY; WHISTLER INSTABILITY; ELECTRON-ION COLLISIONS; ELECTRON TEMPERATURE; HEAT FLUX; ASTROPHYSICS

Citation Formats

Gary, S.P., Neagu, E., Skoug, R.M., and Goldstein, B.E. Solar wind electrons: Parametric constraints. United States: N. p., 1999. Web. doi:10.1029/1999JA900244.
Gary, S.P., Neagu, E., Skoug, R.M., & Goldstein, B.E. Solar wind electrons: Parametric constraints. United States. doi:10.1029/1999JA900244.
Gary, S.P., Neagu, E., Skoug, R.M., and Goldstein, B.E. Wed . "Solar wind electrons: Parametric constraints". United States. doi:10.1029/1999JA900244.
@article{osti_688001,
title = {Solar wind electrons: Parametric constraints},
author = {Gary, S.P. and Neagu, E. and Skoug, R.M. and Goldstein, B.E.},
abstractNote = {Solar wind electrons are often observed to consist of two distinguishable components, a thermal, more dense core and a suprathermal, less dense halo. In this core/halo model linear Vlasov theory for the whistler heat flux instability predicts dimensionless heat flux thresholds which decrease as the electron core beta, {tilde {beta}}{sub {parallel}c}, increases. It has been proposed that this theoretical threshold corresponds to an observable upper bound on the electron heat flux. Linear theory also predicts that there is a critical value of {tilde {beta}}{sub {parallel}c} below which the whistler heat flux instability does not have appreciable growth in the solar wind; there is another suggestion that this corresponds to an observable lower bound on {tilde {beta}}{sub {parallel}c}. These two proposals are examined by comparison of linear theory and data from the initial in-ecliptic phase of the Ulysses mission. The instability threshold does provide a statistical constraint on observed solar wind heat fluxes, and the critical {tilde {beta}}{sub {parallel}c} of theory is not inconsistent with a statistical lower bound on the observations of that parameter. {copyright} 1999 American Geophysical Union},
doi = {10.1029/1999JA900244},
journal = {Journal of Geophysical Research},
number = A9,
volume = 104,
place = {United States},
year = {1999},
month = {9}
}