Abstract
The rain/no-rain threshold value of cloud liquid water path is important for rain/no-rain classification in microwave precipitation retrieval algorithms. In our previous study, we proposed a parameterization of rain/no-rain threshold value of cloud liquid water path as a function of storm height for the Global Satellite Mapping of Precipitation (GSMaP) algorithm. In this study, we determine rain/no-rain threshold value of cloud liquid water path using the CloudSat precipitation product. The threshold values of cloud liquid water path from the CloudSat precipitation product are lower than 0.5 kg m-2 for GSMaP over all regions. The threshold value of cloud liquid water path is found at its peak in the tropics and decreases poleward. The threshold value of cloud liquid water content computed from threshold value of cloud liquid water path divided by the zonal mean storm height is employed on the parameterization of threshold values of cloud liquid water path. The result shows that GSMaP with new parameterization can detect the shallow rain observed by CloudSat and improves the rain-rate distribution over rain rate less than 0.1 mm h-1.
