安徽省热对流短时强降水的判别与特征分析

对安徽省2008~2012年5~9月的降水以及气温、地温、日照等要素进行了统计分析,发现午后降水频率明显高于其它时次,在对降水及其他要素进行分类统计的基础上,提出了基于降水特征、午后13时地温、午后13时地温和早上08时的地温差、日照时数的热对流短时强降水的判别方法。基于融合了多重观测资料的LAPS再分析系统得到的中尺度再分析场资料,对2008~2011年5~9月热对流局地强降水进行了比湿、回波、稳定度和能量指标特征统计分析,并对一个典型个例的降水特征、降水成因进行了具体分析,总结了此类降水过程在降水特征、天气形势、湿度条件、大气层结稳定度的特点:维持时间短、强度大,范围小,地面温度高,午后和早上的地温差明显,降水发生前大气不稳定能量较强,中低层风场切变辐合明显。

THE DISCRIMINATION AND ANALYSIS OF THERMAL CONVECTIVE SHORT-DURATION HEAVY PRECIPITATION IN THE YANGZE-HUAIHE RIVER BASIN

A method of discriminating thermal convective short-duration heavy precipitation was developed, based on the characteristic of ground temperature, sunshine duration, precipitation, according to the statistical analysis on factors such as precipitation and temperature, ground temperature, sunshine duration, during May-Aug from 2008 to 2012 in Anhui Province. Frequency of thermal convective short-duration heavy precipitation was significantly higher than other times. The characteristics of specific humidity, radar echo, stability and energy indexes in thermal convective short-duration heavy precipitation in Anhui province was analyzed based on the Statistic of LAPS (Local Analysis Prediction System) data. A typical case was analyzed about the mechanism and characteristics of precipitation. Finally, the characteristics of thermal convective short-duration heavy precipitation was summarized:The maintenance time of rain is short, the rainfall is heavy, the range is small, with high ground temperature, the difference between the ground temperature of afternoon and morning is big, and the instability index value before precipitation is high, but the low-level wind convergence and shear is significant.