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Title: |
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DETAILED EVIDENCE FOR FLARE-TO-FLARE
VARIATIONS OF THE CORONAL
CALCIUM ABUNDANCE
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Authors: |
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J. Sylwester,
J. R. LEMEN,
R. D. A. AND M.-C. BENTLEY, FLUDRA,1 ZOLCINSKI |
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Abstract: |
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The analysis of X-ray solar flare spectra obtained by the Bent
Crystal Spectrometer on board the
Solar Maximum Mission satellite is presented. The ratio of the Ca XIX resonance
line intensity to the
nearby continuum is used to measure the calcium abundance relative to hydrogen
(ACa). A description of the spectroscopic method of determining the absolute calcium abundance is given.
Possible instrumental
and solar effects that might in fluence the abundance estimates are evaluated. Over
5000 spectra from
more than 100 flares are analyzed. We find a flare-to-flare variation for that is
not correlated with ACa flare size,
 importance, or with several other
flare
characteristics. For flares observed from two active
regions, the observed value of increases as a function of time. The average for
all flares is <ACa>= (5.77 ± 1.41) x 10-6. A discussion of investigated correlations of derived values
with several flare ACa characteristics is presented. |
