Some aspects of coronal streamer dynamics.
Abstract
Observations of coronal streamers suggest that these configurations are stationary in terms of the convective time scale, but not with respect to the diffusive processes. In this paper, the diffusive time scale is estimated and the thickness of a stationary streamer where convective and diffusive processes are balanced turns out to be very small. Instead of balancing the terms in the magnetic equation to obtain a zero time derivative, we suggest that the diffusive part is negligible and therefore, the convective term must be zero in the largest part of the streamer. This can be obtained by introducing flux transport through the streamer. We show that the arising convective model is to be understood from evolutionary arguments; the upward flux transport leads to a time scale for the life of a streamer, related to the evolution of the underlying magnetic field. Slight differences occur between stationary models and the present model; these differences are shown not to be in conflict with radio observations.
 Publication:

Solar Physics
 Pub Date:
 July 1977
 DOI:
 10.1007/BF02260209
 Bibcode:
 1977SoPh...53...59W
 Keywords:

 Astronomical Models;
 Convective Flow;
 Diffusion;
 Solar Corona;
 Solar Magnetic Field;
 Dynamic Characteristics;
 Photosphere;
 Solar Wind;
 Stellar Evolution;
 Solar Physics;
 Dynamics:Solar Corona;
 Solar Corona: Streamers