Multiple flows in the solar transition region.
Abstract
The solar transition region between the chromosphere and the corona shows clear evidence of a fine scale structure that is much smaller than the best available instrumental resolution in the UV of 1×1 arcsec. Previous studies have suggested filling factors of 0.01 - 0.001, with the solar gas being restricted to thin, extended fibrills. New evidence of the fine scale structure is found from its dynamical characteristics, the presence of multiple flows. In multiple flows the solar gas in small volumes show several distinct velocities, resulting in line profiles with more than one velocity component within the spatial resolution element. Multiple velocities are particularly prominent above sunspots, but by no means restricted to these regions. Instead they are clearly a general feature in the solar transition region, occurring in quiet as well as active regions.
- Publication:
-
Study of the Solar-Terrestrial System
- Pub Date:
- September 1992
- Bibcode:
- 1992ESASP.346..211B
- Keywords:
-
- Boundary Layer Transition;
- Chromosphere;
- Fine Structure;
- Solar Corona;
- Sunspots;
- Transition Flow;
- Ultraviolet Spectra;
- Data Reduction;
- Flow Velocity;
- High Resolution;
- Solar Physics