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Chromospheric Downflows as a Diagnostic of Solar Flare Heating

Published online by Cambridge University Press:  27 September 2017

Dominic M. Zarro
Affiliation:
Applied Research Corporation, Landover, MD*
Richard C. Canfield
Affiliation:
Institute for Astronomy, University of Hawaii, Honolulu, III

Abstract

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Using coordinated X-ray and Hα observations of five solar flares, we investigate the dynamics of chromospheric condensations formed during chromospheric evaporation. We show that the peak downflow velocity of condensations predicted by simple hydrodynamic compression of the chromosphere is in good agreement with empirical downflow velocities implied by impulsive phase Hα redwing Doppler shifts. This agreement indicates that the Hα wing redshift provides a useful diagnostic of the pressure excess in the evaporating region and, hence, the energy flux driving chromospheric evaporation.

Type
Session II: Solar Flares
Copyright
Copyright © Kluwer 1989

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