Nonphotospheric Abundances in a Solar Active Region

Details Nonphotospheric Abundances in a Solar Active Region Nonphotospheric Abundances in a Solar Active Region

Oct 1993

adsabs.harvard.edu/cgi-bin/nph-data_query?bibcode=1993apj...416..392w&link_type=abstract

Astrophysical Journal v.416, p.392

Astronomy and Astrophysics

Astronomy

36

Sun: Abundances, Sun: Activity, Sun: Uv Radiation

Scientific paper

Element abundances have been determined for a solar active region observed to have a highly nonphotospheric Ne/Mg abundance ratio associated with an open magnetic field. This active region is an example of a class of relatively inconspicuous features with open magnetic fields which contrast with brighter, more compact emission regions with less anomalous abundance ratios. The study is based on images of the active region in Ne VI, VII, Mg VI-VIII, Na VIII, Si VIII, and Ca VIII, IX photographed in the 300-600 Å range by the NRL spectroheliograph on Skylab.
Element abundances relative to magnesium were determined by combining plots of the ion differential emission measures. The electron density was bracketed in the range 4 × 109 to 2 × 1010 cm-3, and ionization equilibrium was assumed. The Ne/Mg abundance ratio was also derived from the Ne VI to Mg VI intensity ratios observed at 400 Å.
We find that the Ne/Mg abundance ratio is 15 times smaller than in the photosphere, whereas the abundances of Na, Si, and Ca relative to magnesium are not different by more than a factor of 2 from the ratios in the photosphere. From other evidence we conclude that the abundances of the low first ionization potential group of elements (Na, Mg, Si, and Ca) are enriched more than tenfold relative to high FIP neon in this region with open magnetic fields. Properties of a similar group of solar features are summarized.

Affiliated with

Also associated with

No associations

Rating

Nonphotospheric Abundances in a Solar Active Region does not yet have a rating. At this time, there are no reviews or comments for this scientific paper.

If you have personal experience with Nonphotospheric Abundances in a Solar Active Region, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Nonphotospheric Abundances in a Solar Active Region will most certainly appreciate the feedback.

Rate now

Comments { 0 }

Profile ID: LFWR-SCP-O-1324745