山东省极端强降水天气概念模型研究

The conceptual models of extreme precipitation weather in Shandong Province

利用山东省1971—1999年逐日降水资料,采用百分位法确定各站极端强降水阈值。据此阈值,在2000—2009年中挑选了39个极端强降水天气过程并进行天气分型,得到高空槽类、副高外围类、切变线类、气旋类、热带气旋类5类极端强降水概念模型。研究表明:切变线类、气旋类和热带气旋类暴雨区范围较大,而高空槽类和副高外围类暴雨区范围较零散;5类极端强降水均伴有低空急流,暴雨区一般位于700 hPa与850 hPa切变线(或槽线)之间、低空急流左侧风向风速辐合处;高空槽类、副高外围类、切变线类一型和气旋类均有冷空气影响,暴雨区位于850 hPa冷温度槽前部;5类极端强降水的产生机制不同,落区与θse的配置也不尽相同。

Threshold value of extreme precipitation of each station was confirmed through the percentile method based on the daily precipitation in Shandong Province from 1971 to 1999. Based on the threshold value, the 39 extreme precipitation events in Shandong Province from 2000 to 2009 were classified to five conceptual models, including upper trough, subtropical high periphery, shear line, cyclone and tropical cyclone types.Results show that the heavy rain area of the shear line, cyclone and tropical cyclone types is often larger, and that of the upper trough and subtropical high periphery types is generally scattered.There is low level jet in all five types, and the heavy rain area generally lies between 700 hPa and 850 hPa shear lines （or trough lines）, at the wind speed convergence on the left side of low level jet.There is cold air in the upper trough type, the subtropical peripheral type and the shear line type 1, and the heavy rain area is located in front of 850 hPa cold temperature trough. For the five types, the mechanisms of extreme precipitation area and θse are not same. are different, and the configurations between heavy rain