1991年江淮梅雨期OLR场的特征  

THE CHARACTERISTICS OF“OLR”FOR 1991 MEI-YU

作　　者：蒋尚城[1] 杨喜峰[1] 韦革 杨文斌 

机构地区：[1]北京大学地球物理系,北京100871

出　　处：《应用气象学报》1993年第3期301-309,共9页Journal of Applied Meteorological Science

基　　金：85-906-08课题

摘　　要：该文利用美国 NOAA 卫星1991年(及1980和1985年)雨季候平均 OLR 资料及常规天气观测资料,对1991年江淮洪涝梅雨的 OLR 场特征进行分析。分析了1991梅雨期的 OLR及其距平场以及季内变化(ISV)的经、纬向传播特征;揭示了 ITCZ 与副热带高压的变化与梅雨的关系以及青藏高原 OLR 的异常与梅雨的关系;指出西太平洋 ITCZ 的提前出现以及青藏高原冬季 OLR 的正距平(积雪少)是1991年洪涝梅雨提前发生的先兆。最后分析了1991年梅雨活跃期与中断期的 OLR 分布特征,并与印度季风雨相比较,发现两者开始日期不同,且活跃期的位相有时相同,有时相反。指出中国梅雨的复杂性主要由于中纬度冷空气与低纬度两种(东亚及南亚)季风气流的相互作用所致。Using the mean pentad Outgoing Longwave Radiation (OLR) data observed fromthe NOAA satellites and the conventional weather observations for the 1991 mei-yu sea-son,the diagnostic study of the characteristics of the OLR is conducted.The paper de-scribes the OLR and its anomalies pattern and the characteristics of propagation of theintraseasonal variation (ISV) of OLR during the 1991 flood mei-yu periods.It is re-vealed that the variation of the ITCZ and the subtropical high are related to the evolu-tion of the mei-yu.The relationship between the anomalies of OLR over Tibiet Plateauand the flood mei-yu is also revealed.The results show that the earlier ITCZ occurrencein the western Pacific and the positive OLR anomalies (snow cover less than normal)over Tibiet Plateau in winter are the important indications for the earlier onset date ofthe 1991 mei-yu.Finally,by analyzing the features of the OLR pattern for the activeand break phases of the 1991 mei-yu and comparing with that of Indian monsoon,it isfound that their onset dates are different from each other and their active phases eithersame or contrary.It is suggested that the complication of the mei-yu in China is mainlydue to the interaction between the middle latitude cold air and two kinds (east Asia andsouth Asia) of monsoon events.

关 键 词：梅雨 季风 青藏高原 长波辐射 

分 类 号：P426.62[天文地球—大气科学及气象学]