两类El Nino事件对Hadley环流及中国气候的影响分析  

Impacts of two types of El Nino events on the Hadley circulation and climate of China

作　　者：李艳[1] 马百胜 王琪[1] 路瑶 王嘉禾 Li Yan Ma Bai-sheng Wang Qi Lu Yao Wang Jia-he(Key Laboratory for Semi-arid Climate Changes with the Ministry of Education, College of Atmospheric Sciences, Lanzhou University, Lanzhou 730000, Chin)

机构地区：[1]兰州大学大气科学学院半干旱气候变化教育部重点实验室,兰州730000

出　　处：《兰州大学学报（自然科学版）》2017年第5期636-645,共10页Journal of Lanzhou University(Natural Sciences)

基　　金：国家自然科学基金项目(41475076,41305105)

摘　　要：利用1979-2014年的NCEP/NCAR再分析资料,分析了两类El Ni?o事件对Hadley环流及中国地区降水和气温的影响.结果表明,无论在冷季还是暖季,El Ni?o事件使得Hadley环流增强但并未改变Hadley环流中上升支及下沉支的位置;在暖季El Ni?o Modoki事件使得Hadley环流的上升支和下沉支均发生北移,在冷季则没有这种特征.El Ni?o对Hadley环流的影响较El Ni?o Modoki要大,是由两类El Ni?o事件下海温异常分布型的不同造成的.El Ni?o事件下中国南方易出现低温、洪涝,北方易发生高温、干旱,东北易出现冷夏,且易导致暖冬现象.当发生El Ni?o Modoki事件时,在冷季,中国地区气温分布表现为北部和东部地区偏低,西部及西南部地区较高;在暖季,中国东北地区表现为较强的增温现象,长江以南地区的降水较气候平均态偏少.选择两类El Ni?o事件对Hadley环流影响最大的个例,发现中国气温、降水的异常特征与两类El Ni?o事件影响中国气候变化的统计规律基本相符,表明两类El Ni?o事件对中国气候影响的不同,很大程度上是由于其对Hadley环流的影响不同造成的,其他环流系统的作用使得最终影响更为复杂.With 1979-2014 NCEP/NCAR reanalysis findings, the impacts of two types of El Ni？o events on the Hadley circulation and the climate in China were analyzed, the results showing that either in the cold or warm season during El Ni？o events, Hadley circulation was strengthened with the unconverted position of its rising and sinking branches. In the warm season of El Ni？o Modoki year, rising and sinking branches of Hadley circulation both move northward. This character was not depicted in the cold season of El Nifio Modoki year. The influence of El Nifio on Hadley circulation was bigger than that of El Nifio Modoki, which was caused by a different sea surface temperature（SST） distribution during the two types of El Nifio events. In an El Nifio year, low temperature and floods appeared more easily in southern China and high temperature and drought more easily in northern China. The northeast areas of China underwent a cool summer. The temperature in winter in China would be higher. In an El Ni？o Modoki year, the temperature distribution in the cold season showed a law of being lower in the north and east area and higher in the southwest area. The region to the south of Yangtze River experienced less precipitation. The typical examples indicating that the two types of El Ni？o events had the biggest influence on the Hadley circulation were picked out to analyze the reasons behind the different influences of the two types of El Ni？o on China climate and the results showed that the anomaly of temperature and precipitation during these typical events was basically consistent with the influence climatology of the two types of El Ni？o events in Chinese climate, indicating that the Hadley circulation was an important element among a number of factors through which the anomaly of SST in the equatorial Pacific influenced the climate in China. There were other contributing factors too, making it not easy to figure out the mechanism of the SST influence in Chinese climate.

关 键 词：EL NINO事件 EL Nino Modoki事件 HADLEY环流 中国气候 

分 类 号：P461[天文地球—大气科学及气象学]