The Role of CONVECT10N in Stellar Atmospheres. Observable Effects of Convection in the Solar Atmosphere

A numerical method has been developed to apply Spiegel's theory of convection based on the generalization of the mixing-length formalism for model-atmosphere calculations. The method is used to construct solar model atmospheres under various physical conditions in order to investigate the effect of convective flux on various observable quantities. Due to the nonlocal effect of convective flux from deeper layers taken into account in Spiegel's theory, a significant increase in the observable effect of convection with an increase in the mixing length is seen as compared to that obtained from models based on the usual mixing-length theory. However, a comparison of predicted limb darkening with observations indicates that the ratio of mixing length to pressure scale height cannot exceed 0.35. As a result, the observable effect of convection appears to be negligibly small in the atmospheres of the solar-type stars. Subject headings: atmosphere, solar - atmospheres, stellar - convection