Examining Possibility of Cloud-rain-ice Partitioning Using Satellite-based Cloud Water Estimation Over Land at 36 and 89 GHz

Abstract

　For the monitoring of water and energy cycles, satellite-based cloud water estimations provide valuable information. Nevertheless, most existing methods estimate cloud water with emphasis on one category of cloud particle type. Because differences in cloud particle types affect cloud characteristics, water contents must be estimated separately. Moreover, applying those methods to estimations over land is a widely recognized challenge. This study newly developed a 36.5 GHz estimation method based on 89.0 GHz cloud and land simultaneous estimation (Seto et al., 2018), and compared the features of estimation results of the two methods and satellite cloud radar products. Moreover, based on the revealed features, this study assessed the possibility of cloud-rain-ice partitioned estimation. Results show that liquid water contents over land can be estimated reasonably well using 36.5 GHz. Furthermore, liquid-ice partitioning using the difference between 36.5 GHz and 89.0 GHz measurements and cloud-rain partitioning using the difference between horizontal and vertical polarizations at 36.5 GHz appear to be possible.