近30 a影响皖北东部降水的台风环流场研究

分析1981—2014年7—9月影响皖北东部地区的台风特征,统计不同台风路径和降雨量之间的关系,研究不同路径下皖北东部出现暴雨的环流场特征,结果表明:(1)西北行、陆面转向、海面转向和其他类路径的台风都可以影响皖北东部,并产生降水。其中产生降水个例最多的台风路径为陆面转向类,次多为西北行类。(2)台风影响时无降水、非暴雨和暴雨3类降水个例的500 hPa平均环流场对比分析表明:当有台风影响皖北东部时,配合西风槽或副高阻挡更有利于产生强降水。(3)西北行类台风暴雨的环流场特征是华北到河套存在西南-东北走向高压带阻挡使台风停滞少动;海面转向类台风暴雨环流场特征是河套东部存在低槽与台风相互作用;陆面转向类台风暴雨环流场可以分为3类:贝湖两槽一脊型、贝湖单槽型和副热带高压阻挡型。

A research on typhoon circulation fields affecting precipitation in the northeastern Anhui Province in recent 30 years

Along with analyzing the characteristics of typhoons affecting the northeastern part of Anhui Province in 7-9 months, the relationship between typhoon activity and rainfall is statistically analyzed as well. By studying the characteristics of the rainstorm circulation situations under different typhoons in the northeastern part of Anhui Province, the following results are obtained:(1) Typhoons along northwest route, land steering route, sea steering route and other paths can affect the northeastern Anhui and produce precipitation. Among them, the typhoon path with the most common precipitation cases is the land steering route, and the second is northwest route. (2) The comparative analysis of 500 hPa average circulation field of three types of precipitation, namely, no precipitation, no rainstorm and rainstorm, under the influence of typhoon shows that when typhoon affects the northeastern Anhui, the combination of westerly trough or subtropical high is more conducive to heavy precipitation. (3) The circulation field of typhoon-like torrential rain in Northwest China is characterized by the existence of a southwest-northeast high pressure zone from North China to Hetao area, which make typhoon move slowly. Typhoon-like storm circulation field with sea surface turning is characterized by low trough and typhoon interaction in the eastern part of Hetao area. The circulation fields of land steering typhoon rainstorm can be divided into three types:two troughs and one ridge in Lake Bei, Lake Bei single trough type and subtropical high barrier type.