雷暴大风落区的天气学模型和物理量参数研究

Research of Synoptic Model and Physical Quantity Parameter of Thunder- Gust Winds Impact Area

对1971 2008年山东雷暴大风的气候特征、天气系统配置模型和物理量参数特征进行分析研究。结果表明,雷暴大风的天气系统分为四种类型:槽前型、槽后型、副热带高压(下称副高)边缘型和横槽型。春季和秋季以槽前型为主,6月和8月槽后型较多,副高边缘型只出现在7月。副高边缘型的对流不稳定能量最高,0~6 km风垂直切变最小;槽后型风垂直切变最大,对流不稳定能量也较大;槽前型的风垂直切变和对流不稳定能量都较大;横槽型的风垂直切变和对流不稳定能量都较小。在鲁西北和鲁中地区槽前型最多,鲁南地区槽后型最多,横槽型主要影响山东北部和半岛地区,副高边缘型主要影响鲁西北和鲁中地区。在内陆地区,春季大气湿度小,不稳定能量低、上下层温差大、0~6km风垂直切变大,大风指数大;夏季低层大气暖湿,对流不稳定能量高、风垂直切变小,大风指数小。鲁南地区产生雷暴大风的温湿条件比鲁西北和鲁中地区高。在山东半岛的沿海地区,低层大气湿度大、温度低,对流不稳定能量小,大风指数较小,但是K指数、θse上下层之差和0~6 km风垂直切变较大,低层大气温度和湿度的月变化较小。

The thunder-gust winds in Shandong Province from 1971 to 2008 were statistical analysed and the climate feature was studied. The circulation system and the occurring areas of 93 times regional thunder-gust winds from 2000 to 2008 were researched. The results show that: Four kinds of thunder-gust winds synoptic models were built mainly by 500 hPa influence system: the southerly air flow in the front of trough model,the northerly air flow in the rear of trough model,the west edge of subtropical high model and the front of the lateral trough for revolving to south model. The physical quantity parameters in 93 times thunder-gust wind processed were ferreted out and analyzed. The thunder-gust winds from June to August accounts 63. 1% and most in July. The northwesterly winds were the most wind direction in winds directions of thunder-gust winds. But the southwesterly winds were the most in July. The 8 ~ 9 scale wind power of thunder-gust winds take 80. 8%. In the spring and autumn the thunder-gust winds produced mostly in southerly air flow in the front of trough. The thunder-gust winds in the northerly air flow in the rear of trough model occurred mainly in June and August. The thunder-gust winds in west edge of subtropical high were mainly in July. In the subtropical high west edge model,the convection available potential energy( CAPE) was most high and the 0 ~ 6 km wind vertical shear was the minimum.In the trough rear model,wind vertical shear was the maximum and CAPE was higher. In the trough front model,CAPE and wind vertical shear was all larger. In the lateral trough model CAPE and wind vertical shear were all small. The trough front model was the most in northwest and middle part of Shandong. The trough rear model was the most in south of Shandong. The lateral trough model influence mainly north and peninsula of Shandong and the subtropical high west edge model influence mainly northwest and middle part of Shandong. In the inland in spring atmosphere humidity and CAPE was small,the difference in temperature between high and low level,0~ 6 km wind vertical shear and gale index were all large. In summer,low levels in atmosphere are warm and wet and CAPE was high,but 0 ~ 6 km wind vertical shear and gale index was all smaller. The temperature and humidity condition in south of Shandong was higher than in northwest and middle part of Shandong. In the coast area of peninsula in Shandong,the low level atmosphere was wet and cold and CAPE was lower and gale index smaller. But K index,the θsedifference between high and low level and 0 ~ 6 km wind vertical shear were large.The month change of temperature and wet in low level atmosphere was small.