On physical conditions in the chromosphere above sunspot umbrae.
Abstract
By means of an inversion of H and K Ca II line profiles the temperature and electron density in the chromosphere above the umbrae of two sunspots have been estimated. The temperature gradient 5 K km−1 exceeds the corresponding values in both quiet regions and plages. At a height of about 1500 km the umbra becomes hotter than the quiet region. At a temperature of about 10000 K the temperature gradient increases sharply. The electron density at 1500 km is approximately the same as that in the quiet chromosphere at the same height.
- Publication:
-
Solar Physics
- Pub Date:
- February 1978
- DOI:
- 10.1007/BF00152473
- Bibcode:
- 1978SoPh...56..293T
- Keywords:
-
- Chromosphere;
- Electron Density (Concentration);
- Solar Temperature;
- Sunspots;
- Umbras;
- Calcium;
- Faculae;
- H Lines;
- K Lines;
- Temperature Distribution;
- Temperature Gradients;
- Solar Physics;
- Physical Condition;
- Temperature Gradient;
- Line Profile;
- Quiet Region;
- Sunspot Umbra;
- Electron Densities:Solar Chromosphere;
- Solar Chromosphere:Temperatures;
- Sunspots: Umbrae