试论湖北省伏旱的环流特征

通过对湖北省几个典型伏旱年的同期环流特征的分析，揭示了与湖北严重伏旱灾害密切联系的几中大气环流系统，并进行了分型。指出，造成严重伏旱的主要天气系统有西太平洋副热高压，西风带环流和西太平洋台风，并根据伏旱期大气环流的不同型式，将造成湖北伏旱的环流特征主要归结为两类，一是副高势力强盛，西伸强烈，稳定控制长江中下游地区；中高纬度向环流占优势；台风活动较少，另一类是副高压势力较弱，主体位于太平洋面上空，西

ON THE GENERAL CIRCULATION FEATURES OF DROUGHT DURING DOG DAYS SEASON IN HUBEI PROVINCE

By analyzing several canonical atmosphere general circulation of dog-days drought years in Hubei province, the atmosphere general circulation which are closely related to serious drought during dog-days are reviewed and classified into different models.It is pointed out that the major weather systems which result in serious drought during this season are the west Pacific subtropical high,westerly circulation and west Pacific typhoons.According to the different circulation patterns,the circulation which bring about the dog days drought are divided into two types:(1) subtropical high prevails,extending westward and strongly affects the weather along the middle and lower reaches of the Yangtze River;more obvious latitudinal circulation at middle high latitudes,less typhoons.(2) the subtropic high is much weaker and is located above the Pacific ocean;more typhoons over the Pacific ocean but it is difficult for them to land and move northward.