Relationship between Solar Net Radiative Fluxes at the Top of the Atmosphere and at the Surface

Abstract Previous work has discussed the existence of a linear relationship between the net solar radiative flux densities at the surface and at the top of the atmosphere (TOA) that can be exploited for inferring the net surface radiation directly from the satellite observed net radiation. In physical terms the net solar flux at the surface can be estimated from the difference between the satellite-inferred net flux at TOA and total solar absorption in the atmosphere. This paper presents model calculations of the influence on solar absorption of water vapor, solar zenith angle, cloud-top altitude, and cloud optical thickness. The model results indicate a somewhat complex relation between the solar net fluxes at the surface and at the top of the atmosphere. It is pointed out that cloud altitude and optical depth have a large impact on solar atmospheric absorption; high clouds decrease solar absorption by the atmosphere whereas low clouds increase it. This difference between solar atmospheric absorption for...