A 2 year comparison of AMSR‐E and MODIS cloud liquid water path observations

Abstract

An extensive comparison of cloud liquid water path (LWP) observations from solar reflectance and passive microwave satellite measurements over the global oceans is presented. Two years of MODerate resolution Imaging Spectroradiometer (MODIS) and Advanced Microwave Scanning Radiometer‐EOS (AMSR‐E) LWP observations were collocated at full resolution and compared under special conditions to minimize errors, i.e., overcast, low‐level liquid clouds with no detectable precipitation. Best agreement occurred in stratus regions off the west coasts of North/South America, southern Africa, and Australia. Large differences found in the winter hemispheres at higher latitudes were caused by a strong dependence of MODIS optical depth retrievals on solar zenith angle. Other differences, notably in the tropics and parts of the subtropics, were due to a dependence of AMSR‐E LWP observations on surface wind speed and total precipitable water. Results highlight the need to provide more accurate cloud LWP observations for climate studies and model verification.