新疆冰雹天气中尺度特征分析

Abstract

针对2007~2016年新疆30场冰雹天气11种强对流参数的归纳分析表明，冰雹天气发生时，K指数大于30℃，沙氏指数小于2℃，湿对流有效位能大于150 J/kg，最大上升速度超过10 cm/s，对流抑制有效位能0~30 J/kg，风暴强度指数230~280、抬升凝结高度超过600 m，平衡高度230~700 m，自由对流高度550~1000 m。利用FY-2D红外云图和NECP再分析资料，采用卫星云图数字处理方法和低通滤波技术，对南疆西部一次冰雹和暴雨天气的对比分析表明，冰雹过程中TBB低且梯度强，经过中尺度滤波后，冰雹和暴雨天气均由中-β尺度引发，冰雹天气气象要素的变化强度强于暴雨天气。 The analysis on 11 convection parameters of 30 hailstorm in Xinjiang during period of 2007-2016 showed that the hailstorm would begin when K index was greater than 30˚C, SI index was less than 2˚C, moist convective available potential energy was more than 150 J/kg, maximum climbing speed was more than 10 cm/s, convective inhibitive available potential energy was in the range of 0 - 30 J/kg, storm intensity exponent was in the range of 230 - 280, lifting condensation level was more than 600 m, balance height was in the range of 230 - 700 m and free convective height was in the range of 550 - 1000 m. The analysis of infrared satellitic cloud image of FY-2D and reanalyzed dada of NECP for single sample of the hailstorm and rainstorm in the West of South Xinjiang by digital processing method and low pass filter technique showed that the value of TBB was low and had a high gradient. Moreover, both hailstorm and rainstorm were introduced by mesos–β cale and the variation strength of the weather meteorological factors of hailstorm was stronger than that of rainstorm.