Convection and the solar granulation
Abstract
Theories of the hydrodynamics of the convection zone of the solar atmosphere are examined and compared with observations of solar granulation, which they are intended to explain. One approach to the problem attempts to determine convective energy flux by describing fluid elements in the mixing length approximation. The mixing length theory, however, cannot be used directly for dynamic aspects of stellar convection. The thermal convection theory attempts to solve the hydrodynamic equations more exactly, based on the laws of fluid dynamics. The mixing length models are shown to be inadequate to describe the observed discrete wave numbers of spatial power spectra and inconsistent with the observations of spectral distribution and granule size, distribution and radiation. The discrete wave number observations along with an observed high correlation between granule velocity and intensity tend to support the thermal convection theory.
 Publication:

Recent Developments in Theoretical and Experimental Fluid Mechanics: Compressible and Incompressible Flows
 Pub Date:
 1979
 Bibcode:
 1979rdte.book..386N
 Keywords:

 Free Convection;
 Mixing Length Flow Theory;
 Solar Atmosphere;
 Solar Granulation;
 Atmospheric Models;
 Convective Flow;
 Cross Correlation;
 Hydrodynamic Equations;
 Power Spectra;
 Temperature Gradients;
 Solar Physics