| WANG Yanshuo,HUANG Fei,FAN Tingting. 2017. Spatio-temporal variations of Arctic amplification and their linkage with the Arctic oscillation. Acta Oceanologica Sinica, 36(8):42－51 |
| Spatio-temporal variations of Arctic amplification and their linkage with the Arctic oscillation |
| 北极放大的时空变化特征及其与北极涛动的联系 |
| Received:March 29, 2016 |
| DOI：10.1007/s13131-017-1025-z |
| Key words:Arctic amplification Arctic oscillation decadal shift mid-latitude |
| 中文关键词: 北极放大 北极涛动 年代际转型 中纬度 |
| 基金项目:The Global Change Research Program of China under contract No. 2015CB953904; the National Natural Science Foundation of China under contract Nos 41575067 and 41376008. |
| Author Name | Affiliation | E-mail | | WANG Yanshuo | Physical Oceanography Laboratory/CIMST, Ocean University of China, Qingdao 266100, China
Qingdao National Laboratory for Marine Science and Technology, Qingdao 266200, China
Ningbo Collabrative Innovation Center of Nonlinear Harzard System of Ocean and Atmosphere, Ningbo University, Ningbo 315211, China | | | HUANG Fei | Physical Oceanography Laboratory/CIMST, Ocean University of China, Qingdao 266100, China
Qingdao National Laboratory for Marine Science and Technology, Qingdao 266200, China
Ningbo Collabrative Innovation Center of Nonlinear Harzard System of Ocean and Atmosphere, Ningbo University, Ningbo 315211, China | huangf@ouc.edu.cn | | FAN Tingting | Physical Oceanography Laboratory/CIMST, Ocean University of China, Qingdao 266100, China
Qingdao National Laboratory for Marine Science and Technology, Qingdao 266200, China | |
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| Abstract: |
| The Arctic near-surface air temperatures are increasing more than twice as fast as the global average-a feature known as Arctic amplification (AA). A modified AA index is constructed in this paper to emphasize the contrast of warming rate between polar and mid-latitude regions, as well as the spatial and temporal characteristics of AA and their influence on atmospheric circulation over the Northern Hemisphere. Results show that AA has a pronounced annual cycle. The positive or negative phase activities are the strongest in autumn and winter, the weakest in summer. After experiencing a remarkable decadal shift from negative to positive phase in the early global warming hiatus period, the AA has entered into a state of being enlarged continuously, and the decadal regime shift of AA in about 2002 is affected mainly by decadal shift in autumn. In terms of spatial distribution, AA has maximum warming near the surface in almost all seasons except in summer. Poleward of 20°N, AA in autumn has a significant influence on the atmospheric circulation in the following winter. The reason may be that the autumn AA increases the amplitude of planetary waves, slows the wave speeds and weakens upper-level zonal winds through the thermal wind relation, thus influencing surface air temperature in the following winter. The AA correlates to negative phase of the Arctic oscillation (AO) and leads AO by 0-3 months within the period 1979-2002. However, weaker relationship between them is indistinctive after the decadal shift of AA. |
| 中文摘要: |
| 北极近表面气温增暖速率超过全球平均水平，这个现象被称为北极放大（AA）。本文构建了一个改进的AA指数来强调北极和中纬度增暖率之间的差异，以及AA的时空特征和其对北半球大气环流的影响。结果表明AA有显著的季节变化，在秋冬季最强，夏季最弱。在全球变暖减缓初期，AA完成了由负位相到正位相的显著的年代际转型并进入了持续放大时期，这个在2002年的年代际转型主要体现在秋季AA的年代际转。从空间分布来看，除了夏季外的其余季节AA的最大增暖都在近地面。在20°N以北，秋季AA对随后冬季的大气环流有显著影响。其原因可能在于，秋季AA通过使得行星波的振幅加大，波速减慢，并通过热成风关系使得对流层上层纬向风减弱，进而影响到随后冬季的表面气温。在1979-2002年间AA和北极涛动（AO）负位相有显著的正相关关系，且AA超前于AO 0-3个月。然而在AA年代际转型后它们的关系并不显著。 |
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