Linear hydrodynamical equations coupled with radiative transfer in a nonisothermal atmosphere. II: Application to solar photospheric observations.
Abstract
In a previous paper (Schmieder, 1977), we solved simultaneously the hydrodynamical and radiative transfer equations, so we do not have to assume any relaxation time of the atmosphere. In this paper, we use that theory to interpret photospheric observations of the Mg i line at 5172 Å. For periods between 400 and 140 s, the phaseshifts observed between velocities and the phase shifts between intensity and velocity fluctuations are explained by the existence of radiative dissipation coupled with evanescent waves or upward propagating waves, according to the frequency. For smaller periods partial or total reflections must be considered. The results relative to radiative dissipation are expressed in terms of the variation of a relaxation time with frequency through the atmosphere (10^{3}<τ_{5000}<1).
 Publication:

Solar Physics
 Pub Date:
 April 1978
 DOI:
 10.1007/BF00160098
 Bibcode:
 1978SoPh...57..245S
 Keywords:

 Atmospheric Models;
 Hydrodynamic Equations;
 Linear Equations;
 Photosphere;
 Radiative Heat Transfer;
 Solar Atmosphere;
 Atmospheric Temperature;
 Cooling;
 Line Spectra;
 Phase Shift;
 Relaxation Time;
 Solar Spectra;
 Solar Physics;
 Hydrodynamics:Solar Atmosphere;
 Radiative Transfer:Solar Photosphere