论文部分内容阅读
通过涡旋自组织动力学方法对西北地区几次暴雨过程进行了分析,得到了一些暴雨过程中降水云团自组织预报的判据和指标：（1）产生暴雨的云团发展演变大都经历了由无组织到有组织、由不规则云形到有规则云形的过程;（2）造成甘肃暴雨过程的降水云团一般由2～4个范围在35km×35km左右的小云团合并而成,合并过程一般为两两合并,范围在110km×110km左右的小云团合并时间一般为3～4h,范围在200km×200km左右的云团合并时间一般为9～10h,而范围〉220km×220km的云团一般不会自组织成功;（3）能够自组织成功的小云团中心TBB一般在220K左右;（4）甘肃降水云团TBB中心值基本在220K左右,强度较我国南方降水云团强度偏弱,且降水对流体移动较快;（5）几个降水较大的测站基本位于TBB等值线密集带附近,云团西面的TBB等值线密集,东部较稀疏。通过分析发现,涡旋自组织也是造成干旱半干旱地区暴雨等灾害性天气形成的重要原因之一。“,”Based on the vortex self-organization dynamics method,several rainstorm processes in Northwest China were analyzed, the obtained results are as follows：（1） Most of cloud clusters produced heavy rainstorm experience the process from the non-organized to organized and from irregular to regular clouds;（2） The precipitation clouds cause the rainstorm of Gansu Province which generally united by two to four little clouds about 35 km×35 km,the combination time of 110 km×110 km clouds is 3～4 h,the time of 200 km×200 km clouds is 9～10 h,The clouds of more than 220 km×220 km are not self-organizing success;（3） The TBB centers are successful in sell-organizations which generally are about 220 K;（4） TBB center of cloud clusters in Gansu Province is about 220 K,the intensity of TBB is weaker than the clouds in southern China,and the convective system of Gansu Province move faster;（5） Precipitation cell are basically located in dense with TBB contours,and on the western side of TBB contours are more intensive,relatively east sparse.The analysis shows that the vortex self-organization is an important reason cause heavy rainfall in arid and semi-arid regions and an important basis to improve the physical mechanism of the development of rainstorm.