Spatio-temporal variations of Arctic amplification and their linkage with the Arctic oscillation

• Published in: Acta oceanologica Sinica Vol. 36; no. 8; pp. 42 - 51
• Main Authors: Wang, Yanshuo, Huang, Fei, Fan, Tingting
• Format: Journal Article
• Language: English
• Published: Beijing The Chinese Society of Oceanography 01.08.2017; Springer Nature B.V; 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%Physical Oceanography Laboratory/CIMST, Ocean University of China, Qingdao 266100, China
• Subjects: Air temperature; Amplification; Annual variations; Arctic Oscillation; Atmospheric circulation; Autumn; Circulation; Climate change; Climatology; Earth and Environmental Science; Earth Sciences; Ecology; Engineering Fluid Dynamics; Environmental Chemistry; Global warming; Marine & Freshwater Sciences; Northern Hemisphere; Oceanography; Planetary waves; Polar environments; Sea surface temperature; Seasons; Spatial distribution; Summer; Surface temperature; Surface-air temperature relationships; Temperature; Temperature effects; Temporal variations; Wind; Winds; Winter; Zonal winds; 中纬度地区; 北极涛动; 大气环流; 年代际变化; 放大; 时空变化; 时空特征; 空气温度; Arctic; Arctic region; Arctic oscillation; Arctic amplification; decadal shift; mid-latitude
• ISSN: 0253-505X; 1869-1099
• DOI: 10.1007/s13131-017-1025-z

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.