Time Variations of the Calcium Elemental Abundance in Flares from NOAA Active Regions 2562 and 2779

J. Sylwester, M.-C. Zolcinski-Couet, R.D. Bentley, J.R. Lemen
1988 International Astronomical Union Colloquium  
AbstractAnalysis of flare spectra obtained with the Bent Crystal Spectrometer aboard the Solar Maximum Mission (SMM) satellite enables the determination of the fluxes in the resonance (w) line of Ca XIX and the near-by continuum. The line-to-continuum intensity ratio is a sensitive measure of the calcium elemental abundance (Aca) relative to hydrogen in the emitting plasma. In previous investigations we found the calcium abundance varies from flare to flare. In the present investigation we
more » ... vestigation we analyse the variations ofAcafor flares which occurred in two active regions well observed bySMM. We conclude that it is not possible to correlate the abundance variations with the time of the flare occurrence as suggested in an earlier paper for flares produced from a single active region. Further, we find no convincing correlation of abundance variation with any other flare characteristics. This negative result will stimulate future work on the physical interpretation of the calcium abundance variation.
doi:10.1017/s0252921100107675 fatcat:mjvrwznwx5d37bsnceptpet4iq