两次超强厄尔尼诺事件海温异常与次年中国东部夏季降水特征对比  

Contrast of characteristics of SST anomaly and the summer rainfall in East China in the following years of two strong El Niňo events

作　　者：罗婷 李丽平[3] 王远清 LUO Ting;LI Liping;WANG Yuanqing(Sanya Meteorological Bureau of Hainan Province,Sanya 572000,China;Key Laboratory of South China Sea Meteorological Disaster Prevention and Mitigation of Hainan Province,Haikou 570203,China;Collaborative Innovation Center on Forecast and Evaluation of Meteorological Disasters(CIC-FEMD)/Key Laboratory of Meteorological Disaster,Ministry of Education(KLME)/School of Atmospheric Sciences,NUIST,Nanjing 210044,China)

机构地区：[1]海南省三亚市气象局,海南三亚572000 [2]海南省气象防灾减灾重点实验室,海南海口570203 [3]南京信息工程大学气象灾害预报预警与评估协同创新中心/气象灾害教育部重点实验室/大气科学学院,江苏南京210044

出　　处：《大气科学学报》2019年第5期715-724,共10页Transactions of Atmospheric Sciences

基　　金：海南省气象局青年基金资助项目(HNQXQN201610)

摘　　要：利用NOAA逐月海表温度(SST)资料,NCEP/NCAR风场、高度场和比湿再分析资料和国家信息中心提供的753站逐日降水资料,对比分析了1997/1998年和2015/2016年两次强厄尔尼诺事件的海温异常分布特征、次年中国东部夏季降水以及环流异常特征,结果表明:1)2015/2016的厄尔尼诺事件是自1950年以来持续时间最长,强度最强的一次事件,日界线附近的海温较1997/1998年的偏高。2)1997/1998年厄尔尼诺事件次年华南西部、江南北部到长江流域、黄淮北部到华北南部以及我国东北地区降水较常年偏多。而2015/2016年厄尔尼诺事件次年降水范围和强度相对较小,强雨带主要分布在长江流域一带、黄淮地区和华北一带及河套北部。3)1997/1998年事件次年夏季西北太平洋副热带高压强盛,位置偏西,脊线偏南,向上垂直质量输送异常偏强、高低层水平风场配合以及水汽通量异常辐合偏强均有利于长江流域一带以及我国东北地区降水产生,而2015/2016年事件次年的副高相对偏弱,且脊线位置偏北、偏东,水平、垂直异常环流和水汽偏弱,因此降水范围和程度较1997/1998年的偏弱。从海温分布型和次年对我国东部夏季降水造成的影响上看,2015/2016年的超强厄尔尼诺事件有别于传统东部型事件。Based on the monthly sea surface temperature(SST)data from American National Oceanic and Atmospheric Administration,NCEP/NCAR monthly reanalysis data of wind field,potential height field and humidity as well as daily rainfall data from 753 stations provided by the Chinese National Meteorological Information Center,the characteristics of abnormal SST distribution,summer precipitation in eastern China in the following year and atmospheric circulation anomalies of two strong El Ni o events in 1997/1998 and 2015/2016 were compared and analyzed.The results showed that:1)The 2015/2016 El Ni o event had been the longest and strongest one since 1950 and the magnitude of SST near the date-line was larger than that in 1997/1998;2)During the following summer of 1997/1998 El Ni o,more precipitation occurred in the west of the southern China,the north of Jiangnan area to the Yangtze river basin,the northern part of Huang-Huai area to the southern part of North China and Northeast China;precipitation intensity was weaker and the distribution of anomalous rainfall was smaller in the following summer of 2015/2016,in which the heavy rain belt mainly distributed in the Yangtze river basin,Huang-Huai area and the northern area of the Great Bend of the Yellow River;3)It was found that the Western North Pacific subtropical high(WNPSH)was strong and its location was to the west of its usual position while the ridge line was to the south of its usual position in the following summer of 1997/1998;the abnormally strong mass transportation vertically and upwards,the horizontal wind field of the upper and lower levels and the anomalous convergence of water vapor flux were all favorable for precipitation in the Yangtze river basin and Northeast China in the following year of 1997/1998 El Ni o event;in 2016,the WNPSH was weaker and the ridge line was to the north and east of its usual position;the weaker horizontal and vertical circulation anomalies as well as weaker water vapor conditions made the coverage and intensity of summer precipitat

关 键 词：厄尔尼诺 东部降水 水平风场 垂直质量输送 水汽通量 

分 类 号：P73[天文地球—海洋科学]