Cloud drop effective radius as observed from aircraft, MODIS and MISR

Cloud microphysical properties derived from passive satellite remote sensing have found widespread use in studies of the energy and water cycles of our planet. Here we provide a broad perspective on the accuracy of the effective radius of the drop size distribution of liquid water clouds derived from MODIS (Moderate resolution Imaging Spectroradiometer) based on a detailed analysis of in situ cloud microphysical probes mounted on aircrafts, 1-D and 3-D radiative transfer simulations, and a close look at the cloudbow observed in the MISR (Multi-angle Imaging SpectroRadiometer, on Terra) radiance. Estimates of the accuracy in effective radius from MODIS as a function of geographical location and season will be presented. This provides a basis for interpreting the space-time variability of cloud drop effective radius found within the MODIS product. We discuss a path forward that connects the systematic error with cloud heterogeneity as a means of bias correction.