Ice cloud microphysical properties in tropical Pacific regions derived from CloudSat and CALIPSO measurements

We revealed the difference in tropical ice cloud microphysical properties between the western Pacific (WP) and the eastern Pacific (EP), based on satellite retrievals. Vertical profile of effective particle radius of ice cloud (r_e) was estimated from active sensors on board CloudSat and CALIPSO satellites. In this study, we focused only on ice cloud which is defined as clouds with the cloud top temperature lower than 0°C. To investigate the relationship between cloud optical properties and cloud vertical structures, these ice clouds were classified into five types based on cloud optical thickness values. Compared the vertical profile of r_e in WP with that in the EP, r_e around the freezing level within convective cloud in EP slightly larger than that in WP. This analysis also shows that r_e of optically thick cloud is larger than that of optically thin cloud. The difference in r_e may be caused by differences in moisture convergence, upward motion, aerosols.