Identification and Effect Verification of Convective Cloud Precipitation in Rainstorm Processes Based on SWAN Mosaic Products
Based on SWAN (Severe Weather Automatic Nowcast System) radar mosaic products, we selected the composite reflectivity factor and its horizontal gradient, echo top height and vertically integrated liquid water content as identification parameters, and conducted a classification test for convective cloud and stratiform cloud precipitation in rainstorm processes using the fuzzy logic method. The results were verified by 12 regional rainstorm processes that occurred in Chongqing. Taking the Advanced TOA and Direction System lightning data as objective observation data of convective cloud precipitation, we tested the related products quantitatively by four different radiuses of spatial matching and four different time matching methods, respectively. The verification results showed that with the increase of space matching radius, the correct rate improves significantly. However, the correct rate of 6 min cloudtoground lightning flashes relative to 6 min mosaic products ahead of 6 min, 3 min, 0 min and lagging 3 min four time matching methods, changes slightly. The overall score of the rainstorm is high and the test method has clear physical meaning. The score results under different temporal and spatial matching patterns are consistent with the actual situation, which means the classification outcome of the convective and stratiform rainfall is good. This is an exploration of convective cloud precipitation quantitative test as well.