Solar Physics

, Volume 113, Issue 1–2, pp 307–311 | Cite as

Chromospheric downflow velocities as a diagnostic in solar flares

  • G. H. Fisher


We explore the dynamics of chromospheric condensations driven by evaporation during the impulsive phase of solar flares. Specifically, we find that the maximum chromospheric downflow speed obeys the approximate relation υd= 0.4 (Fch)1/3, where F is that part of the flare energy flux driving chromospheric evaporation, and ϱch is the mass density in the preflare chromosphere just below the preflare transition region. This implies that chromospheric downflows as measured by Hα asymmetries may be a powerful probe of flare energetics.


Evaporation Flare Transition Region Mass Density Energy Flux 


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Copyright information

© D. Reidel Publishing Company 1987

Authors and Affiliations

  • G. H. Fisher
    • 1
    • 2
  1. 1.Institute for Astronomy, University of HawaiiHonoluluUSA
  2. 2.Institute of Geophysics and Planetary Physics Lawrence Livermore National LaboratoryLivermoreUSA

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