1961-2019年黑龙江省冬季气温季节内变化及环流异常特征

Intraseasonal variation of wintertime air temperature in Heilongjiang province and circulation anomalous characteristics from 1961 to 2019

利用1961—2019年黑龙江省冬季气温、NCEP再分析资料和环流指数资料,采用多变量经验正交函数分解、合成分析、相关分析等方法,分析黑龙江省冬季气温季节内变化及其环流异常特征,并进一步对比了主要环流因子在冬季气温季节内演变不同模态中的相对贡献。结果表明:季节内变化是黑龙江省冬季气温变化的基本特征。黑龙江省冬季气温存在季节内一致变化、12月和翌年1—2月反位相变化、12月至翌年1月和2月反位相变化三个主要模态。当冬季气温处于第一模态分布一致偏暖(冷)时,环流呈现北极涛动(AO)正(负)位相的分布特征,东亚冬季风(EAWM)偏弱(强)。当冬季气温发生季节内冷暖转换时,季内极涡、高空急流、西伯利亚高压(SH)和EAWM强度、中高纬环流经向度等均有明显调整。第二模态1月和第三模态2月环流场分别呈现类似极地欧亚型(PEA)和东大西洋型(EA)遥相关的分布特征。AO、SH、EAWM、PEA和EA是冬季气温季节内演变的重要影响因子。

Based on air temperature data,the National Centre for Environment and Prediction(NCEP)reanalysis data,and circulation indices in Heilongjiang province in winter from 1961 to 2019,we analyzed the intraseasonal variation of wintertime air temperature in Heilongjiang province and the circulation anomalous characteristics using the methods of multivariate empirical orthogonal function(EOF)decomposition,synthetic analysis,correlation analysis,etc.We also compared the relative contribution of main circulation factors in the different modes during the intraseasonal evolution of temperature.The results showed that the intraseasonal variation of wintertime air temperature in Heilongjiang province is one of its basic features.There are three major modes for wintertime air temperature in Heilongjiang province,including the intraseasonal consistent variation,the antiphase variation between December and January-February in the next year,and the antiphase variation between December-January and February.When the air temperature in winter shows the first mode and distributes uniformly warm(cold),the circulation is characterized by an Arctic Oscillation(AO)positive(negative)phase and relatively weaker(stronger)East Asian winter monsoon.When a warm-cold transition occurs in winter,significant variation can be found in the intraseasonal polar vortex,the upper-level jets,the Siberian High(SH),and EAWM intensity,and mid-high latitudes circulation meridian,etc.The circulation in January in the second mode and in February in the third mode show a similar distribution to the Polar Eurasian(PEA)and the East Atlantic(EA)teleconnections,respectively.AO,SH,EAWM,PEA,and EA are the important influencing factors on the intraseasonal variation of wintertime air temperature.