PNNL

Abstract

We have developed a look-up table approach for retrieving dominant cloud phase (water or ice) and ice crystal habit from coincident Multiangle Imaging Spectroradiometer (MISR) and Moderate Resolution Imaging Spectro radiometer (MODIS) data. We present statistics of retrieved cloud phase and crystal habit for years of Terra overpasses of the Atmospheric Radiation Measurement (ARM) Program's Southern Great Plains (SGP) site. This analysis focuses on clouds which have optical depth > 2 and are likely to be single-layer (or have an optically thick upper layer). For these clouds, 48% of retrieved clouds were dominated by scattering from water droplets while aggregates were the most commonly retrieved ice crystal habit (27% of all retrieved clouds; 51% of retrieved ice clouds). The distinction between water and ice clouds is more robust than the distinction between individual crystal habits. For ice habits, the strongest distinctions were found between aggregate like and plate-like habits. Comparison with MODIS operational cloud property retrievals (MOD06) illustrates the strong dependence of retrieved optical depth and e®ective radius on habit assumptions.