On the inability of magnetically constricted transition regions to account for the 105 to 106 K plasma in the quiet solar atmosphere
Abstract
Although `back conduction' from the corona has been shown to be inadequate for powering EUV emission below T ≈ 2 × 105 K, it is thought to be adequate in the temperature range 2 × 105 K < T < 106 K. No models to date, however, have included the large magnetic constriction which should occur in the legs of coronal loops where conductive `transition regions', hitherto thought to contain the bulk of the plasma in this higher temperature range, are located. On the basis of fine scale magnetograms, Dowdy et al. (1986) have estimated that these magnetic flux tubes are constricted from end to end by an areal factor of approximately 100. Furthermore, on the basis of simple steady-state conductive models, Dowdy et al. (1985) have shown that the large constriction can inhibit the conductive flow of heat by an order of magnitude. We are thus led to re-examine static models of this region of the atmosphere which incorporate not only conduction and radiation but also the effects of large magnetic constrictions. We find that the structure of this plasma depends not only on the magnitude of the constriction but also on the tube's shape.
- Publication:
-
Solar Physics
- Pub Date:
- September 1987
- DOI:
- 10.1007/BF00148781
- Bibcode:
- 1987SoPh..112..255D
- Keywords:
-
- Coronal Loops;
- Extreme Ultraviolet Radiation;
- Plasma Temperature;
- Solar Atmosphere;
- Solar Magnetic Field;
- Transition Points;
- Conductive Heat Transfer;
- Magnetic Flux;
- Stellar Models;
- Solar Physics;
- Transition Region;
- Flux Tube;
- Coronal Loop;
- Magnetic Flux Tube;
- Differential Emission Measure