中国近100年来4个年代际的气候变化特征

4-PHASE CLIMATE CHANGE FEATURES IN THE LAST 100 YEARS OVER CHINA

研究了本世纪中国年平均气温、年总降水量的气候趋势。指出，２０世纪中国西北、东北、华北明显变暖；降水趋势值不大，但以负趋势为主。２０世纪８０年代中国降水、气温的区域特征明显：华北暖干、西南冷干、东北暖略偏湿、长江中下游冷湿。此外，还研究了２０世纪４个年代际的气候变化特征及差异。指出，在数十年尺度的暖背景下，中国的华北、长江下游等大部分地区降水偏少（比冷背景），东北降水偏多。２０世纪７０年代开始的增暖主要发生在西北、东北；黄河以南的增温还达不到４０年代的程度。相应的降水特征：除了黄河以南及江淮流域降水比４０年代多以外，其它大部分地区降水偏少。

n this study, the climate trend of the annual average air temperature and total annual rainfall in China in the present century has been examined. It is noted that the Northwest.the North China have become notably warmer this century but the rainfall trend has not been evident. mainly negative. In the 1980s China's rainfall and temperature showed noticeable regional features f warm and dry in North China, cold and dry in the Southwest.warm and wet in the Northeast area, cold and wet in the middle-lower reaches of the Changjing River.Besides. the 4-phase climate features and differences of this century have been studied.It is found that on the scale of tens of years there was considerably less rainfall in most of China in the warm background than in the cold background. The increase of temperature which started from the 1970's was mainly experienced in the Northwest and Northeast,while in the southen part of the Huanghe River the temperature increase did not even reach the level of the 1940' s.The corresponding rainfall feature is that most of the areas experienced much less rainfall except in the south of the Huaihe River and over reaches of the Changjiang and Huaihe Revers.