Solar wind electrons: Parametric constraints
- Los Alamos National Laboratory, Los Alamos, New Mexico (United States)
- Jet Propulsion Laboratory, Pasadena, California (United States)
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
- OSTI ID:
- 688001
- Journal Information:
- Journal of Geophysical Research, Vol. 104, Issue A9; Other Information: PBD: Sep 1999
- Country of Publication:
- United States
- Language:
- English
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