中国冬季气温不同年代际的季节内变化特征及成因分析  

Characteristics and Causes of Intraseasonal Variation of Winter Temperature in China under Different Interdecadal Scale

作　　者：马锋敏[1] 陈丽娟[2,3] 李想[2] 李维京[2,3] 许彬 MA Fengmin;CHEN Lijuan;LI Xiang;LI Weijing;XU Bin(The Climate Center in Jiangxi Province,Nanchang 330096;Laboratory for Climate Studies/CMA(China Meteorological Administration)–NJU(Nanjing University)Joint Laboratory for Climate Prediction Studies,National Climate Center,Beijing 100081;Collaborative Innovation Center on Forecast and Evaluation of Meteorological Disasters,Nanjing University of Information Science&Technology,Nanjing 210044)

机构地区：[1]江西省气候中心,南昌330096 [2]国家气候中心中国气象局气候研究开放实验室/中国气象局—南京大学气候预测研究联合实验室,北京100081 [3]南京信息工程大学气象灾害预报预警与评估协同创新中心,南京210044

出　　处：《大气科学》2022年第3期573-589,共17页Chinese Journal of Atmospheric Sciences

基　　金：国家自然科学基金项目41275073;国家重点研发计划项目2018YFC1506006;国家重点基础研究发展计划项目2015CB453203。

摘　　要：利用1951~2020年中国观测站气温资料、NCEP/NCAR再分析资料和统计方法,分析了不同年代际时间尺度背景下我国冬季气温的季节内变化特征及相联系的大气环流异常。结果表明,1986年前、后为两个年代际时间尺度阶段,各阶段内前冬(12月)与后冬(1~2月)气温异常反位相年的比例均高于同位相年。1986年之前,季节内的优势空间模态为前冬全国冷(暖)转为后冬南方暖(冷)的可能性大,即南方地区季节内变率大;而1986年之后的优势空间模态为前冬北方冷(暖)转为后冬全国明显暖(冷)的可能性大,即北方地区季节内变率大。冬季气温的季节内变化显著受到冬季风系统关键环流季节内变化的影响。对应优势模态的正异常年份,1986年之前,欧亚中高纬地区对流层环流异常信号从前冬到后冬显著性减弱,其中西北太平洋地区对流层中高层的环流调整更明显,副热带高度场增强,热带东风急流北扩,前冬到后冬的环流调整有利于前冬全国大范围偏冷而后冬我国南方地区气温升高,造成南方地区季节内反位相变率增大。1986年之后,欧亚高中低纬地区的环流异常从前冬到后冬显著性增强,欧亚中高纬度环流发生较大调整,而低纬度的环流变化不大,北方地区前冬冷到后冬全国明显转暖,造成北方地区季节内反位相变率大。即副热带环流和中高纬度环流分别在两个年代际尺度阶段南方和北方的冬季气温季节内变率中起到主导作用。This study investigates the intraseasonal variation characteristics of winter temperature in China and related atmospheric circulation anomalies under two different interdecadal time scale stages,classified as before and after 1986,using observed temperature data in China from 1951 to 2020,NCEP/NCAR reanalysis dataset,and statistical methods.The proportion of anti-phase years of temperature in early winter(December)and late winter(January–February)is higher in each stage than in the same phase years.Furthermore,the season-reliant empirical orthogonal function(S-EOF)method was used to obtain the dominant modes of the interseasonal variation in winter under two interdecadal time scale periods.Before 1986,the dominant spatial mode in winter showed that the national cold(warm)in early winter was likely to change to the warm(cold)in southern China in late winter,implying that the intraseasonal variability in the southern region was greater than that in the northern region.After 1986,the dominant spatial mode is more likely to demonstrate that the cold(warm)in northern China in early winter changed to the obvious warm(cold)in the entire country in late winter,indicating that the intraseasonal variability in the northern region is greater than that in the southern region.The interseasonal variation of winter temperature is significantly affected by the interseasonal variation of the key circulation of the East Asia winter monsoon system.Before 1986,the tropospheric circulation anomaly signal in the middle and high latitudes of Eurasia weakened significantly from early winter to late winter,correlating to the positive phase anomaly years of the dominant mode.The circulation adjustment in the middle and upper troposphere was more prominent in the Northwest Pacific,the subtropical height field was enhanced,and the tropical easterly jet expanded northward.The circulation adjustment in winter is conducive to the country-wide cold in early winter,while warm in southern China in late winter,resulting in strong intraseasonal

关 键 词：冬季气温 年代际时间尺度 季节内变化 优势模态 东亚冬季风 

分 类 号：P461[天文地球—大气科学及气象学]