文献类型：期刊文献

英文题名：Intraseasonal variability modes of winter surface air temperature over central Asia and their modulation by Greenland Sea ice and central Pacific El Nino-Southern Oscillation

作者：Qin, Mingyue[1,2];Li, Shuanglin[1,2];Xue, Yufeng[3];Han, Zhe[4]

机构：[1]Chinese Acad Sci, Climate Change Res Ctr, Inst Atmospher Phys, Beijing 100029, Peoples R China;[2]Univ Chinese Acad Sci, Beijing, Peoples R China;[3]Guangdong Ocean Univ, Coll Ocean & Meteorol, Zhanjiang 524008, Guangdong, Peoples R China;[4]Chinese Acad Sci, Inst Atmospher Phys, Key Lab Reg Climate Environm Temperate East Asia, Beijing, Peoples R China

年份：2022

卷号：42

期号：15

起止页码：8040

外文期刊名：INTERNATIONAL JOURNAL OF CLIMATOLOGY

收录：SCI-EXPANDED(收录号：WOS:000822624700001)、、WOS

基金：National Natural Science Foundation of China, Grant/Award Number: 41790473; National Science and Technology Major Project, Grant/Award Number: 2018YFA0606403

语种：英文

外文关键词：central Asia temperature; central-Pacific El Nino; intraseasonal variability; sea ice

外文摘要：The two dominant patterns of the winter (December-February) intraseasonal surface air temperature (SAT) over central Asia is derived by empirical orthogonal function analysis, with the first (mode 1) featuring a regional monopole and the second (mode 2) featuring a northwest-southeast-orientated dipole. Mode 1 is characterized with warmer (colder) Arctic and colder (warmer) Eurasia along with an anomalous high (low) over the Ural Mountains, while mode 2 is characterized with northwest-southeast dipole over Eurasia along with wave train-like atmospheric circulation anomalies from the western Atlantic to Asia. Whether the two intraseasonal modes are modulated by lower-boundary forcing is then investigated, and the results suggest that mode 1 is significantly modulated by sea ice concentration over the Greenland Sea, but by central-Pacific ENSO for mode 2. Finally, the underlying mechanisms are diagnosed, and the results suggest that the diabatic heating related with decreased sea ice in Greenland Sea induce a positive height anomaly over Urals which favours the formation of Ural blocking and therefore tends to intensify the occurrence of mode 1. Also, central-Pacific El Nino excites the Pacific-North American teleconnection, which alters North Atlantic subtropical jet extension, favours intensified energy conversion to intraseasonal wave train and subsequently intensifies the occurrence of mode 2. This study highlights the joint role of Arctic sea ice and the SST in the tropical central Pacific.