Relating Shortwave Passive Remote Sensing and Radiative Effects of Aerosol-immersed Broken Cloud Fields

With the advent of new satellite sensors, significant advancements have been made for the observation of clouds and aerosols in isolation. For complex aerosol-immersed broken cloud fields, by contrast, it is still difficult to interpret the combined spectral signature of clouds, aerosols, and the surface in passive remote sensing. Even if aerosol and cloud properties are known within a domain of interest, it is non-trivial to derive the associated irradiance fields, let alone top-of-atmosphere and surface radiative effects. We discuss how the effects of spatially complex cloud fields, aerosols, and the surface manifest themselves in pixel-level and domain-averaged radiances and irradiances, drawing upon a combination of field measurements, large eddy simulations, and three-dimensional radiative transfer calculations. We then address the question of the degree to which aerosol, cloud, and surface properties have to be known in complex scenes in order to derive their individual as well as their combined radiative effects. To examine the relationship between radiances (i.e., remote sensing) and irradiances (i.e., radiative effects), we employ a statistical framework and a new approach to parameterize net horizontal photon transport. This enables a quantification of imagery-derived cloud and aerosol radiative energy budget terms with their uncertainties.