摘要:利用1980~2014年CRU TS3.24月平均气温数据和NCEP/NCAR再分析资料，分析了中国东北暖季（5~9月）气温的时空变化特征及其相应的大气环流状况。结果表明：中国东北暖季气温主要表现为全区一致型和南北反位相型两个模态，二者总解释方差高达86%。全区一致型具有明显的年代际变化特征，并在1990年代中期发生了显著的年代际突变，而南北反位相型具有明显的年际和年代际变化特征。全区一致型增暖对应着中国东北地区上空500 hPa位势高度的正异常和850 hPa的反气旋环流异常。当500 hPa位势高度南北反相时，对应于中国东北暖季气温的南北反位相型。进一步分析表明中国东北暖季气温的全区一致型及其1990年代中期的年代际突变与日本海及黑潮延伸区的海温异常及太平洋年代际振荡和大西洋多年代际振荡指数紧密相关。菲律宾以东的西太平洋、北太平洋中部、我国东南沿海、靠近北美东北部的北大西洋等海域的海温异常对中国东北暖季气温全区一致型的出现具有一定的预测作用。而南北反位相变化型与黑潮延伸区的海温异常关系显著，与大尺度指数的相关普遍不明显。在1990年代中期突变前，南北反位相型受到ENSO事件的影响，之后影响不显著。
关键词:中国东北/
暖季气温/
大气环流/
海温异常/
大尺度指数
Abstract:The warm season is defined as the months from May to September and the variability of warm season surface air temperature (WSAT) over northeastern China (NEC) and its corresponding regional atmospheric circulation are investigated based on monthly average temperature from Climatic Research Unit Version 3.24 and reanalysis data from the NCEP/NCAR dataset for the period of 1980-2014. The results show that there are two major modes of the WSAT over NEC, with the first mode describing a homogeneous structure and the second mode describing a seesaw pattern. These two modes explain 78.2% and 8.6% of the variance, respectively. The first mode exhibits obvious interdecadal variation characteristics with an abrupt shift in the mid-1990s, while the second mode shows both interannual and interdecadal variabilities. The consistent WSAT warming in the whole NEC corresponds to positive 500-hPa geopotential height anomaly and 850-hPa anticyclonic anomaly over NEC, while the seesaw pattern of WSAT over the NEC corresponds to 500-hPa geopotential height anomalies that are opposite in the northern and southern parts of NEC. Further analysis shows that the first mode and its shift in the mid-1990s are closely related with sea surface temperature (SST) anomalies in the Sea of Japan and the Kuroshio extension as well as the Pacific Decadal Oscillation (PDO) and Atlantic Multidecadal Oscillation (AMO). SST anomalies over the western Pacific to the east of the Philippines, the central North Pacific, the southeastern coast of China, and the North Atlantic near the northeastern North America all have implications for the prediction of WSAT in NEC. The second mode is closely associated with SST anomaly in the Kuroshio Extension, but has no significant relations with global climate indices. Before the abrupt shift in the mid-1990s, the second mode is affected by ENSO events. After that, the impacts of ENSO are not significant.
Key words:Northeastern China/
Warm season surface air temperature/
Atmospheric circulation/
Sea surface temperature anomaly/
Climate indices
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