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Title: A statistical study of effects of IMF B sub Z and solar wind speed on auroral ion and electron precipitation

Abstract

The variation in the average particle number and energy flux in the high-latitude region is determined as a function of the solar wind velocity, V{sub SW}, and the Z component of the interplanetary magnetic field, B{sub Z}. The study is made using the data from the SSJ/4 detectors on the satellites of the Defense Meteorological Satellite Program. From the average spectra, the average integral energy and number fluxes for electrons and ions are calculated in each spatial bin. These values are then spatially integrated to give the average hemispheric inputs of the integral particle energy and number flux. Both quantities are found to vary in a simple and consistent manner with both V{sub SW}and B{sub Z}. For both electrons and ions the variation with B{sub Z} tends to a minimum value for weak to moderately strong B{sub Z} positive. For decreasing values of B{sub Z} from the minimum, both quantities increase at a rate greater than linear. For increasing values of B{sub Z} from the minimum, both quantities tend to increase, least for the hemispheric electron energy flux and most for the hemispheric ion number flux. The variation in both quantities with V{sub SW} for both electrons and ions ismore » generally linear with the steepest slopes for the electron hemispheric energy flux. The variation with B{sub Z} and V{sub SW} for all four quantities can be well fit by a simple quadratic equation either of the form f(B{sub Z}, V{sub SW}) = a(B{sub Z} {minus} b){sup 2} + cV{sub SW} + d or f(B{sub Z}, V{sub SW}) = (a(B{sub Z} {minus} b){sup 2} + 1)(cV{sub SW} + d). Either form indicates that the variation is no greater than quadratic in B{sub Z} and no more than linear in V{sub SW} and that the variation is approximately symmetric for values above and below the minimum value of B{sub Z}, namely, b. This result is significantly different than either the half-wave rectifier or epsilon function for describing the solar-wind magnetospheric interaction.« less

Authors:
; ;  [1]
  1. Geophysics Lab., Hanscom AFB, MA (USA)
Publication Date:
OSTI Identifier:
5315259
Resource Type:
Journal Article
Journal Name:
Journal of Geophysical Research; (United States)
Additional Journal Information:
Journal Volume: 96:A4; Journal ID: ISSN 0148-0227
Country of Publication:
United States
Language:
English
Subject:
71 CLASSICAL AND QUANTUM MECHANICS, GENERAL PHYSICS; AURORAL ZONES; CHARGED-PARTICLE PRECIPITATION; ELECTRON PRECIPITATION; EARTH MAGNETOSPHERE; INTERACTIONS; INTERPLANETARY MAGNETIC FIELDS; SOLAR WIND; STATISTICS; VARIATIONS; EARTH ATMOSPHERE; MAGNETIC FIELDS; MATHEMATICS; SOLAR ACTIVITY; 640201* - Atmospheric Physics- Auroral, Ionospheric, & Magetospheric Phenomena

Citation Formats

Brautigam, D H, Gussenhoven, M S, and Hardy, D A. A statistical study of effects of IMF B sub Z and solar wind speed on auroral ion and electron precipitation. United States: N. p., 1991. Web. doi:10.1029/91JA00157.
Brautigam, D H, Gussenhoven, M S, & Hardy, D A. A statistical study of effects of IMF B sub Z and solar wind speed on auroral ion and electron precipitation. United States. https://doi.org/10.1029/91JA00157
Brautigam, D H, Gussenhoven, M S, and Hardy, D A. 1991. "A statistical study of effects of IMF B sub Z and solar wind speed on auroral ion and electron precipitation". United States. https://doi.org/10.1029/91JA00157.
@article{osti_5315259,
title = {A statistical study of effects of IMF B sub Z and solar wind speed on auroral ion and electron precipitation},
author = {Brautigam, D H and Gussenhoven, M S and Hardy, D A},
abstractNote = {The variation in the average particle number and energy flux in the high-latitude region is determined as a function of the solar wind velocity, V{sub SW}, and the Z component of the interplanetary magnetic field, B{sub Z}. The study is made using the data from the SSJ/4 detectors on the satellites of the Defense Meteorological Satellite Program. From the average spectra, the average integral energy and number fluxes for electrons and ions are calculated in each spatial bin. These values are then spatially integrated to give the average hemispheric inputs of the integral particle energy and number flux. Both quantities are found to vary in a simple and consistent manner with both V{sub SW}and B{sub Z}. For both electrons and ions the variation with B{sub Z} tends to a minimum value for weak to moderately strong B{sub Z} positive. For decreasing values of B{sub Z} from the minimum, both quantities increase at a rate greater than linear. For increasing values of B{sub Z} from the minimum, both quantities tend to increase, least for the hemispheric electron energy flux and most for the hemispheric ion number flux. The variation in both quantities with V{sub SW} for both electrons and ions is generally linear with the steepest slopes for the electron hemispheric energy flux. The variation with B{sub Z} and V{sub SW} for all four quantities can be well fit by a simple quadratic equation either of the form f(B{sub Z}, V{sub SW}) = a(B{sub Z} {minus} b){sup 2} + cV{sub SW} + d or f(B{sub Z}, V{sub SW}) = (a(B{sub Z} {minus} b){sup 2} + 1)(cV{sub SW} + d). Either form indicates that the variation is no greater than quadratic in B{sub Z} and no more than linear in V{sub SW} and that the variation is approximately symmetric for values above and below the minimum value of B{sub Z}, namely, b. This result is significantly different than either the half-wave rectifier or epsilon function for describing the solar-wind magnetospheric interaction.},
doi = {10.1029/91JA00157},
url = {https://www.osti.gov/biblio/5315259}, journal = {Journal of Geophysical Research; (United States)},
issn = {0148-0227},
number = ,
volume = 96:A4,
place = {United States},
year = {Mon Apr 01 00:00:00 EST 1991},
month = {Mon Apr 01 00:00:00 EST 1991}
}