Year-to-year variability of surface air temperature over China in winter
Year-to-year variability of surface air temperature over China in winter
复制标题
中国冬季地面气温的年际变化
DOI：
10.1002/joc.5289
复制
发表时间：
2017
期刊：
影响因子：
--
通讯作者：
He Qiong
中科院分区：
文献类型：
--
作者：
Xiao Dong;Zuo Zhiyan;Zhang Renhe;Zhang Xingyu;He Qiong
利用1961-2014年中国冬季地面气温（SAT）的年际变化特征进行了分析。结果表明，SAT的年际变异可以解释中国大部分地区SAT变异的30%以上，其中华南、东北和西北地区的SAT变异可达60%以上。除青藏高原和西南地区的小区域外，中国大部分地区的主导型年际SAT表现出均匀的变化。北方太平洋环流是这种均匀变率型的关键因素。北方太平洋对流层中高层异常反气旋环流和减弱的中纬度西风急流与中国上空的均匀温暖有关。第二型为南北偶极子型，东北地区的变化与25°N以南地区和青藏高原的变化相反。南北偶极型是全球年平均卫星辐射异常型的一部分，因为它与欧亚大陆50°N以北大部分地区的年平均卫星辐射有着显著的关系。北冷/南暖型伴随着北极涛动的显著减弱。与南北偶极型相比，均匀变率型对应的大气环流异常要弱得多。前一年秋季印度洋偶极子的异常和11月中国附近的积雪是造成这种均匀型的两个关键原因。热带中太平洋海温（SST）、平流层准两年振荡（QBO）、鄂霍次克海冰和西西伯利亚积雪等因子对南北偶极子型有显著影响。与热带太平洋海温相比，印度洋海温对中国冬季海温的影响更为重要。
In this study, the year-to-year variability of surface air temperature (SAT) over China in winter was investigated during 1961–2014. The results indicate that the year-to-year SAT variability can explain more than 30% of the SAT variance over most parts of China, with up to 60% variance over southern China, northeastern China and northwestern China. The leading pattern of year-to-year SAT exhibits homogeneous variability over most parts of China, except in small areas over the Tibetan Plateau and southwestern China. The circulation over the northern Pacific is a key factor of this homogeneous variability pattern. An anomalous anticyclonic circulation and weakening midlatitude westerly jet in the middle and high troposphere over the northern Pacific are associated with the homogeneous warmth over China. The second pattern shows a south–north dipole, with variability in northeastern China opposite to that south of 25°N in China and over the Tibetan Plateau. The south–north dipole pattern is part of a global year-to-year SAT anomaly pattern because it exhibits a significant relationship with the year-to-year SAT over large parts north of 50°N over the Eurasian landmass. The north-cold/south-warm pattern is accompanied by a significant weakening of the Arctic Oscillation. In comparison, the atmospheric circulation anomalies associated with the homogeneous variability pattern are much weaker than those with the south–north dipole pattern. The anomalous Indian Ocean dipole in the previous autumn and the snow cover around China in November are the two key causes of the homogeneous variability pattern. Many factors, such as the tropical central Pacific sea surface temperature (SST), stratospheric quasi-biennial oscillation (QBO), Okhotsk sea ice and western Siberia snow cover, can significantly influence the south–north dipole pattern. Compared to the tropical Pacific SST, the impact of the Indian Ocean SST on the winter SAT over China is much more important.