Comprehensive Analysis of Satellite and Other Observations from a Convective Clouds Merger

Making use of Chinese satellite in geosynchronous orbit (FY2) information on cloud physical characteristics parameters of the retrieval, routine operational radio-sounding data and observations by microwave radiometer, analysis of a strong precipitation process of the structural features of cloud and precipitation in July 17, 2008, Shou County of Anhui Province in China, some interesting results are presented. (1)The development of convective clouds merger is the main reason for heavy precipitation occurs. The distribution and evolution of FY2 satellites retrieved cloud optical thickness is well consistent with radar echo of the corresponding region, as well as the precipitation on the ground. Heavy rainfall areas, a height cloud optical thickness values area and the strong radar echo area are in good agreement. (2) Cloud liquid water distribution is very uneven with group block structure. Once the convective cloud clusters merge, the cloud optical thickness and liquid water path(LWP) in the combined parts increased rapidly, the ground microwave radiometer observations of the whole layer of liquid water content dramatic changes, and the ground heavy precipitation occurs. (3) Analysis of the T-re time and vertical evolution of convective cloud merger,the vertical structure of cloud particle effective radius was found:the initial merging of convective clouds, clouds base with small particles, cloud particle effective radius of the vertical distribution of the T-re relations showed a deep zone of diffusional growth .The effective radius of the entire layer significantly increased , precipitation threshold of cloud particle effective radius (14um) reached at a lower height, mixed phase and glaciation temperature was reached at a warmer layer. (4) Combination of sounding cloud analysis found that, when the thick cloud of non-sandwich cover and cloud optical thickness is large, the ground prone to precipitation. On the other hand, if there are mezzanine or low-level clouds have more dry regions, even if cloud top higher, cloud optical thickness larger, the ground can not create an effective precipitation.