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1997－98年发生了近百年最强的厄尔尼诺现象，本文对1997－98年冬季（12－2月）500hPa环流特征、东亚温带气旋活动及天气特征进行了分析．同时也对多年厄尔尼诺过程、非厄尔尼诺过程相对应的大气环流及天气特征做了对比分析．研究表明，厄尔尼诺年北半球500hpa环流30°N以南低纬地区位势高度偏高：中纬度的槽脊分布与多年平均有较大不同，东亚大槽偏弱，同时北美大槽减弱，北太平洋高压也减弱，西风环流指数偏强，西太平洋副热带高压西伸明显，强度偏强．中国东部沿海气旋分布特征为北部偏少，南部明显偏多：降水为东部沿海地区偏多明显；气温为南部海区出现高温的机率较大。
In 1997-98, the strongest El Niño phenomenon occurred in nearly a century. In this paper, the characteristics of the 500hPa circulation in the winter of 1997-98 (December-February), the temperate cyclone activity in East Asia and the weather characteristics were analyzed. At the same time, the atmospheric circulation and weather characteristics corresponding to El Niño process and non-El Niño process are comparatively analyzed. The results show that the El Niño 500hpa Northern Hemisphere has a high geopotential height at low latitudes south of 30 ° N: the mid-latitude ridge distribution is quite different from the multi-year average, and the East Asian trough is weaker while the North American trough weakened. At the same time, High pressure also weakened, the westerly circulation index was stronger, and the western Pacific subtropical high was obviously extended in the west and stronger in intensity. The distribution of cyclones in the eastern coast of China is characterized by a small number of northern parts and a markedly more southern part. Precipitation is more obvious in the eastern coastal areas, and the temperature is more likely to occur in the southern part of the sea.