1998年广东省三次暴雨过程的湿有效能量分析  

Analysis of the Moist Available Energy of Three Cases of Guangdong Heavy Rain in 1998

作　　者：周海光[1] 刘延英[1] 刘蔚[1] 

机构地区：[1]中国气象科学研究院灾害天气国家重点实验室,北京100081

出　　处：《应用气象学报》2006年第1期10-18,共9页Journal of Applied Meteorological Science

基　　金：科技部国家重点基础研究发展规划项目(2004CB418305);科技部2002年度科研院所社会公益研究专项资金项目(2002DIA20013)共同资助

摘　　要：湿有效能量对暴雨等灾害性天气的形成、发展和维持等具有重要作用。该文利用改进的计算湿有效能量表达式,计算了1998年5月14—15日、5月23—24日和6月8—9日广东省三次暴雨的湿有效能量,分析了暴雨区湿有效能量的时间演变特征、空间演变特征、水平积聚以及与暴雨的关系。结果表明:暴雨过程前后湿有效能量有显著差异,暴雨开始时湿有效能量高,暴雨过后湿有效能量低,前后相差6×105J/m2以上;三次大降水时段都是在南北湿有效能量差最大值附近,在大降水前,南北湿有效能量差数值的增大主要是由于长江中游的低能区的加强和南扩造成的;长江中游的低能区对三次暴雨大降水有重要影响,这说明中纬度对广东省暴雨的重要性;大降水时段处于湿有效能量平均积聚量最强的时候,此时,广东省的积聚量远高于长江中游地区。It is well known that the moist available energy （MAE） plays an important role on the broken, development and maintenance of the heavy rain. In order to study the MAE of the Huanan heavy rain and the relationship of the Huanan heavy rain to the MAE, the MAE of three heavy rain fall cases in Guangdong Province in 1998 are calculated using developed formula of MAE, one case is on 14-15 May, the other two cases are on 23-24 May and on 8-9 June. The evolvement and convergence of the heavy rain MAE are analyzed. The space-time relationship between the MAE and the heavy rain is also studied. It shows that the MAE at Guangdong Province and the surrounding area plays an important role on the heavy rain fall period. The high MAE at Guangdong Province supplies the energy for the heavy rain. The low MAE over the middle reaches of Changjiang River helps to form the energy front, at the same time, it can result in heavy rain fall directly or indirectly. The MAE of the heavy rain has quite different in the early and later period of the heavy rain. The evolution of the MAE during the heavy rain procedure oscillates obviously. The MAE is high in the pre-heavy rain period but low after the rain. The difference value between the early and later rain fall period exceeds 6×10^5 J/m^2. In order to study the energy threshold of the heavy rainfall, the MAE relative value is defined. This item increases obviously before the heavy rainfall period in the three cases, it indicates that the MAE relative value can reveal the MAE variety characteristic before the heavy rainfall period. As a result, this relative value can be used as a criterion in forecasting the heavy rainfall in the future. The strong rainfall period in the three heavy rain cases is in good agreement with the highest difference value of the MAE between the north and south area. The difference value of the MAE between the north and south area increases because the low MAE value area in the middle reaches of Changjiang River strengthens and moves south wards, which can

关 键 词：暴雨 大降水时段 湿有效能量 

分 类 号：P458.121.1[天文地球—大气科学及气象学] O241.5[理学—计算数学]