[A-CG36] Satellite Earth Environment Observation

[ACG36-08] Examining possibility of cloud/rain/ice water path partitioning over land using passive microwave observations

*Rie Seto¹, Shinjiro Kanae¹ (1.Tokyo Institute of Technology)

Keywords:liquid cloud and rain partitioning, passive microwave observations, over land

For the monitoring of water and energy cycles, satellite-based cloud water estimations provide valuable information. However, most existing methods estimate cloud water with emphasis on one category of hydrometeor type. Because the features of the rainfall carried by a cloud system can vary depending on the particle type distribution within the cloud system, even with the same total water content. Thus, water contents must be estimated separately. Moreover, applying those methods to estimations over land is a widely recognized challenge. This study developed a 36.5 GHz method of estimating total liquid water path, and partitioning it into liquid cloud and rain water paths over land using the difference between horizontal and vertical polarizations at 36.5 GHz. The method was validated by satellite cloud radar products and the results show that liquid water paths over land can be estimated reasonably well using 36.5 GHz. Furthermore, based on comparison between the features of estimation results of 36.5 GHz method and 89.0 GHz method, the possibility of cloud–rain–ice partitioned estimation was assessed. Assessment results showed that the 36.5 GHz method of this study can reduce information needed for total liquid water path estimation and save high-frequency microwave observations, which indicates the possibility to partition liquid and ice water path using the difference between 36.5- and higher-frequency measurements.