College of Oceanic and Atmospheric Sciences, Ocean University of China
利用1979~2019年NOAA（美国国家海洋和大气局）月平均OLR资料，1960~2019年NCEP/NCAR（美国气象环境预报中心和美国国家大气研究中心）和ECMWF（欧洲中期天气预报中心) ERA5月平均再分析资料，以及East Anglia大学CRU地表气温观测资料，采用合成分析方法，探讨了热带太平洋异常对流纬向位置不同的El Ni?o事件对区域气候的影响。结果表明：基于热带太平洋异常对流活动纬向位置，研究El Ni?o事件对大气环流和区域气候异常的影响，可避免SST异常反映大气对流活动异常存在局限性的缺陷。超强El Ni?o事件中，热带太平洋异常对流位置偏东，位于140°W附近。热带东西太平洋异常下沉区偏东，导致澳大利亚东北部和巴西东北部从9月到次年2月严重高温干旱，而秘鲁和厄瓜多尔沿岸降水偏多。9~11月PNA（太平洋-北美）遥相关波列位置偏东，北美大槽显著减弱，使冬季北美大陆气温明显偏高。格陵兰岛到欧洲西北部位势高度偏低，亚欧北部显著偏暖。一般东部型El Ni?o事件中，异常对流位于赤道160°W附近。热带东西太平洋异常下沉区较超强事件偏西，导致澳大利亚西北部和南美西北部从9月到次年5月持续干旱，澳大利亚东部降水正常偏多。PNA波较超强事件偏西，北美大槽加深，秋冬季北美东部出现严寒。而El Ni?o Modoki事件中，异常对流位于180°附近，秘鲁和厄瓜多尔沿岸处于对流抑制区，降水偏少，受异常反气旋持续控制，澳大利亚大部分地区从9月到次年5月持续干旱。PNA波列更加偏西，冬季北美东南部偏冷。一般东部型事件和El Ni?o Modoki事件冬季，大西洋表现为NAO（北大西洋涛动）负位相，亚欧中纬度地区气温偏低。
Based on NOAA (National Oceanic and Atmospheric Administration) monthly OLR data during 1979 to 2019, NCEP/NCAR (National Centers for Environmental Prediction/National Center for Atmospheric Research Reanalysis), ECMWF (European Centre for Medium-Range Weather Forecasts) ERA5 monthly reanalysis datasets, and East Anglia CRU (Climatic Research Unit) surface temperature data during 1960 to 2019, the effects of El Ni?o events with anomalous convection at different zonal position on regional climate are discussed. The results show that: Studying the effects of El Ni?o events on atmospheric circulation and regional climate anomalies based on the zonal position of tropical Pacific anomalous convection can avoid the limitation that SST anomalies cannot reflect the atmospheric convection anomalies fully. The anomalous convection is located near 140°W in Super El Ni?o events. Anomalous subsidence over tropical western and eastern Pacific is eastward, resulting in higher temperature and drought in northeastern Australia, northeastern Brazil, and more rainfall along the coasts of Peru and Ecuador during boreal autumn and winter. The PNA (Pacific-North American) wave train is located eastward, which significantly weakens the North American trough and brings warmer winter in North American. The geopotential height from Greenland to northwest Europe is low, making northern Eurasian significantly warmer. In Eastern El Ni?o, the anomalous convection is located near 160°W. Accordingly, anomalous subsidence is westward, causing dry northwestern Australia, northwestern South America and wet eastern Australia from boreal autumn to spring. The PNA wave train originates in south of Aleutian Islands and deepens the North American trough, causing severe cold winter in eastern North America. The anomalous convection is located near 180 ° in El Ni?o Modoki. Contrary to Super El Ni?o, the coasts of Peru and Ecuador is dry due to abnormal subsidence and most of Australia tends to experience drought from boreal autumn to spring under the controlled of anomalous anticyclone. The PNA wave train is located westward, resulting in severe cold winter in southeastern America. In the winter of Eastern and El Ni?o Modoki events, the Atlantic shows a negative NAO (North Atlantic Oscillation) pattern, and the temperature in the middle latitudes of Eurasian is low.