高原边坡复杂地形下短时强降水的云型特征分类

利用逐时雨量资料、常规高低空观测资料及FY-2卫星云图,对2010—2015年5—9月甘肃省高原边坡复杂地形下76次短时强降水过程个例的天气形势配置及卫星云图演变特征进行统计分析。结果表明,与甘肃省短时强降水过程相关的特征云型共有6类:副热带高压边沿型、逗点云型、冷锋前部型、冷锋尾部与南亚高压东侧叠置型、冷涡后部型、弱冷锋前部椭圆形MαCS型。其中,副热带高压边沿型、冷锋前部型、弱冷锋前部椭圆形MαCS型与低层暖平流强迫有关。逗点云型、冷锋尾部与南亚高压东侧叠置型主要受高低空冷暖平流强烈交汇影响。冷涡后部型是高空冷平流强迫下形成。冷锋尾部与南亚高压东侧叠置型具有较好的预报指示意义。

Cloud Features Classification of Short Time Heavy Rainfall in Complex Topography of Plateau Slope

Based on the observation data and FY 2 satellite cloud image, statistical analysis is carried out on the configuration of weather situation and the evolution of satellite cloud images of 76 short time heavy rainfall processes in Gansu Province during May and September of 2010-2015. The results show that there are six kinds of characteristic cloud types, which are related to the short term heavy rainfall in Gansu Province, including subtropical high edge, comma cloud, front of the cold front, overlay of cold front tail and South Asia high, the back of the cold vortex, elliptic cloud front of the weak cold front. The subtropical high edge, front of the cold front and elliptic cloud front of the weak cold front types, are related to the low level warm advection forcing. The comma cloud and the overlay of cold front tail and east of South Asia types, are mainly affected by strong convergence of warm and cold advections of high and low levels. The back of the cold vortex type is formed by high altitude cold advection. The overlay of cold front tail and east of South Asia type has better predictive indication.