Cloud Features of Tibetan Plateau Vortex Category Cloud Cluster over Different Regions along the Eastward-Moving Path in Summer

Abstract

Using the data of CloudSat satellite, FY series satellite, CMORPH hourly precipitation, and ERA-interim reanalysis products, this paper aims to reveal the cloud features of Tibetan Plateau Vortex (TPV) category cloud clusters over its eastward-moving regions. 107 cases of eastward-moving TPV category that occurred in the summer half-year (April to September) are picked out, and then the cloud features of them are further analyzed by statistics. The results show that the eastward-moving TPV category occurs mostly in May and June, but leastly in July and September. With consecutive enhancement of precipitation intensity and convection intensity, an increasing trend is found in the proportions of deep convection clouds and multiple layer clouds during the TPV category eastward movement. In order to reveal the inner connection among the precipitation intensity, the convection intensity, and the microphysical characteristics of TPV category cloud clusters, the TPV category cloud clusters are classified into different categories by the criteria of the precipitation intensity and the convection intensity separately. Consequently, the two different criteria share the commonality that the number concentration of both ice crystal and cloud droplets increases obviously with the enhancement of precipitation intensity or convection intensity. However, the discrepancy of conclusions also exists between the two classification criteria. A notable stretching upward trend is found in the number concentration distribution of the ice crystal and downward trend in the number concentration distribution of the cloud droplet. The same increasing trend is also discovered in the effective average radius of the ice crystal and cloud droplet. But the TPV category cloud clusters with severe convection do not present the similar variation trend both in the number concentration and the effective average radius. Hence, although the above findings confirm that the precipitation intensity, the convection intensity, and the distribution of cloud hydrometers are associated and interacting mutually, the closed function relationship among them cannot be established, and other meteorology factors related to the ambient conditions should also be taken into consideration as a complete cloud microphysical system.