Comparison of Cloud-Type Properties and Radiative Effect Decomposition in Tropical Convectively Active Regions Using CERES High-Resolution Data

Abstract

Land and oceanic convection exhibit significant contrasts in intensity and entrainment, but their effects on the properties of other cloud types remain unclear. This study examines a 19-year mean of cloud properties and top-of-the-atmosphere (TOA) cloud radiative effects (CREs) by cloud type, with a focus on regional variations across convectively active tropical regions. Forty-two cloud types are classified based on effective cloud-top pressure and cloud optical depth. The analysis reveals distinct regional differences in cloud occurrence and properties, with oceanic regions dominated by convective anvils and boundary-layer clouds, which have higher liquid/ice water contents, while land regions feature higher fractions of mid-level clouds with lower liquid/ice water contents. The study further explores shortwave (SW), longwave (LW), and net CREs, decomposing the contributions of individual cloud types to total CRE differences between two regions into three components: CRE deviations within a cloud type, cloud fraction (CF) deviations, and their combined effect. Results show that CF deviations have the largest impact, enhancing LW warming and SW cooling for mid- and high-level clouds while reducing SW and net cooling for low-level clouds. Although the effects of CRE deviations are smaller than those of CF deviations for individual cloud types, its collective contribution to total regional CRE differences, particularly for net CRE, is more comparable, because the former exhibits consistent regional differences across all cloud types while the latter is influenced by opposing effects between low- and high-level clouds. The decomposition analysis also highlights significant regional variations driven by land-ocean contrasts and meteorological forcings.