McFarlane, SA, Marchand, RT (2008). Analysis of ice crystal habits derived from MISR and MODIS observations over the ARM Southern Great Plains site. JOURNAL OF GEOPHYSICAL RESEARCH-ATMOSPHERES, 113(D7), D07209.
We have developed a look-up table approach for retrieving cloud phase (water or ice) and best-fit ice crystal scattering model from coincident Multiangle Imaging Spectroradiometer (MISR) and Moderate Resolution Imaging Spectroradiometer (MODIS) data. We present statistics of cloud phase and radiatively effective ice crystal habit for 5 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 single-layer (or have an optically thick upper layer). For this subset of clouds, 48% were best fit by a liquid droplet scattering model. The rough aggregate scattering model was the most commonly retrieved ice crystal habit (27% of all retrieved clouds; 51% of retrieved ice clouds). The results indicate that the distinction between water and ice clouds is more robust than the distinction between individual ice crystal habits. For ice clouds, 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 effective radius on habit assumptions.