Wang Zhaomin, Zhang Xiangdong, Guan Zhaoyong, Sun Bo, Yang Xin, Liu Chengyan
1] Polar Climate System and Global Change Laboratory, Nanjing University of Information Science and Technology, Nanjing, China. 210044 [2] Earth System Modelling Center (ESMC), Nanjing International Academy of Meteorological Sciences(NIAMS), Nanjing University of Information Science and Technology, Nanjing, China. 210044.
International Arctic Research Center and Department of Atmospheric Sciences, University of Alaska Fairbanks, 930 Koyukuk Dr., Fairbanks, Alaska 99775, USA.
Sci Rep. 2015 Mar 10;5:8909. doi: 10.1038/srep08909.
A prominent feature of recent climatic change is the strong Arctic surface warming that is contemporaneous with broad cooling over much of Antarctica and the Southern Ocean. Longer global surface temperature observations suggest that this contrasting pole-to-pole change could be a manifestation of a multi-decadal interhemispheric or bipolar seesaw pattern, which is well correlated with the North Atlantic sea surface temperature variability, and thus generally hypothesized to originate from Atlantic meridional overturning circulation oscillations. Here, we show that there is an atmospheric origin for this seesaw pattern. The results indicate that the Southern Ocean surface cooling (warming) associated with the seesaw pattern is attributable to the strengthening (weakening) of the Southern Hemisphere westerlies, which can be traced to Northern Hemisphere and tropical tropospheric warming (cooling). Antarctic ozone depletion has been suggested to be an important driving force behind the recently observed increase in the Southern Hemisphere's summer westerly winds; our results imply that Northern Hemisphere and tropical warming may have played a triggering role at an stage earlier than the first detectable Antarctic ozone depletion, and enhanced Antarctic ozone depletion through decreasing the lower stratospheric temperature.
近期气候变化的一个显著特征是北极地区地表强烈变暖，与此同时，南极洲大部分地区和南大洋普遍降温。更长时间的全球地表温度观测表明，这种两极相反的变化可能是一种年代际半球间或双极跷跷板模式的表现，这种模式与北大西洋海表温度变化密切相关，因此通常被认为起源于大西洋经向翻转环流振荡。在此，我们表明这种跷跷板模式有大气成因。结果表明，与跷跷板模式相关的南大洋表面冷却（变暖）可归因于南半球西风带的增强（减弱），而这可追溯到北半球和热带对流层变暖（变冷）。有人提出南极臭氧消耗是近期观测到的南半球夏季西风增强背后的一个重要驱动力；我们的结果意味着北半球和热带变暖可能在首次可检测到的南极臭氧消耗之前的某个阶段就发挥了触发作用，并通过降低平流层下部温度增强了南极臭氧消耗。
