欧亚大陆冬季地表温度南北反相变化的年代际特征及机理  

Interdecadal Variations and Mechanisms of the Seesaw Pattern for Winter Surface Temperature between Northern and Southern Eurasia

作　　者：李一玲 王澄海[1] 张飞民[1] 

机构地区：[1]兰州大学大气科学学院,甘肃省干旱气候变化与减灾重点实验室,兰州730000

出　　处：《气候与环境研究》2018年第2期161-175,共15页Climatic and Environmental Research

基　　金：国家自然科学基金91437217、41471034、41661144017,公益性行业(气象)科研专项(重大专项)GYHY201506001-4

摘　　要：对欧亚大陆冬季地表温度南北反相的时空分布特征及机理的分析结果表明,欧亚大陆冬季地表温度约以55°N为界存在南北反相变化特征。1961~2015年欧亚大陆冬季地表温度变化具有显著的年际和年代际变化特征;年代际尺度上,北半球行星波"冬三"分布型变化与欧亚大陆地表温度南北反相变化密切联系。冬季欧亚地表温度南北反相变化存在明显的季节内转变。滤除年代际信号和全球变暖趋势后,欧亚大陆冬季地表温度与秋季北极海冰面积之间存在显著相关;北极海冰面积减小是欧亚、尤其中亚地区冬季地表温度降低的主要外强迫因素之一;同期北大西洋"三极子"和欧亚大陆冬季地表温度南北反相变化在年际尺度上存在显著相关。The characteristics and mechanism of the spatial and temporal seesaw pattern of winter surface temperature between northern and southern Eurasia was analyzed. Results show that the seesaw pattern of winter surface temperature between northern and southern Eurasia is evident with the boundary located at about 55°N. Besides, the interannual and interdecadal variations of winter surface temperature over Eurasia are also significant during 1961-2015. On the interdecadal scale, planetary waves in the Northern Hemisphere such as the "Three Troughs/Ridges in winter" are closelyassociated with the seesaw pattern. In addition, this seesaw pattern on the interdecadal scale also has an obvious transitional feature on seasonal scale. Results that exclude the interdecadal and global warming signals indicate that winter surface temperature in Eurasia is significantly correlated with the Arctic sea ice extent in autumn. The decrease in Arctic sea ice extent is one of the main external forcing factors that cause decreases in winter surface temperature in Eurasia, especially in central Asia. Further analysis shows that on interannual time scale, the seesaw pattern has a significant correlation with the synchronous sea surface temperature that displays a "three-pole" structure in the North Atlantic Ocean.

关 键 词：冬季地表温度 年际和年代际变化 大气环流形势 海冰 海面温度 

分 类 号：P461[天文地球—大气科学及气象学]