Solar coronal and photospheric abundances from solar energetic particle measurements
Abstract
Solar energetic particle (SEP) elemental abundance data from the cosmic ray subsystem (CRS) aboard the Voyager 1 and 2 spacecraft are used to derive unfractionated coronal and photospheric abundances for elements with Z = 6-30. It is found that the ionic charge-to-mass ratio (Q/M) is the principal organizing parameter for the fractionation of SEPs by acceleration and propagation processes and for flare-to-flare variability, making possible a single-parameter Q/M-dependent correction to the average SEP abundances to obtain unfractionated coronal abundances. A further correction based on first ionization potential allows the determination of unfractionated photospheric abundances.
- Publication:
-
The Astrophysical Journal
- Pub Date:
- December 1985
- DOI:
- 10.1086/184580
- Bibcode:
- 1985ApJ...299L..57B
- Keywords:
-
- Abundance;
- Energetic Particles;
- Ion Distribution;
- Ionization;
- Photosphere;
- Radiation Measurement;
- Solar Atmosphere;
- Solar Corona;
- Solar Cosmic Rays;
- Charge Distribution;
- Chemical Composition;
- Ion Production Rates;
- Solar Flares;
- Stellar Structure;
- Voyager Project;
- Solar Physics