Abundance variations in solar active regions
Abstract
The diversity in the published values of coronal abundances is unsettling, especially as the range of results seems to be beyond the quoted uncertainties. We present measurements of the relative abundance of iron and neon derived from soft X-ray spectra of active regions. From a data base of over 200 spectra taken by the Solar Maximum Mission Flat Crystal Spectrometer, we find that the relative abundance can vary by as much as a factor of about 7 and can change on timescales of <1 h.
- Publication:
-
Advances in Space Research
- Pub Date:
- 1991
- DOI:
- 10.1016/0273-1177(91)90104-R
- Bibcode:
- 1991AdSpR..11a.151S
- Keywords:
-
- Iron;
- Neon;
- Solar Activity;
- Solar Corona;
- X Ray Spectra;
- Abundance;
- Electron Energy;
- Solar Maximum Mission;
- Solar Physics