DOI: 10.1038/s41561-017-0041-0
论文题名: Role of polar anticyclones and mid-latitude cyclones for Arctic summertime sea-ice melting
作者: Wernli H. ; Papritz L.
刊名: Nature Geoscience
ISSN: 17520894
出版年: 2018
卷: 11, 期: 2 起始页码: 108
结束页码: 113
语种: 英语
Scopus关键词: air mass
; annual variation
; anticyclone
; atmospheric circulation
; cyclone
; extratropical cyclone
; mass transport
; melting
; polar region
; potential vorticity
; sea ice
; summer
; trajectory
; troposphere
; Arctic
英文摘要: Annual minima in Arctic sea-ice extent and volume have been decreasing rapidly since the late 1970s, with substantial interannual variability. Summers with a particularly strong reduction of Arctic sea-ice extent are characterized by anticyclonic circulation anomalies from the surface to the upper troposphere. Here, we investigate the origin of these seasonal circulation anomalies by identifying individual Arctic anticyclones (with a lifetime of typically ten days) and analysing the air mass transport into these systems. We reveal that these episodic upper-level induced Arctic anticyclones are relevant for generating seasonal circulation anomalies. Sea-ice reduction is systematically enhanced during the transient episodes with Arctic anticyclones and the seasonal reduction of sea-ice volume correlates with the area-averaged frequency of Arctic anticyclones poleward of 70° N (correlation coefficient of 0.57). A trajectory analysis shows that these anticyclones result from extratropical cyclones injecting extratropical air masses with low potential vorticity into the Arctic upper troposphere. Our results emphasize the fundamental role of extratropical cyclones and associated diabatic processes in establishing Arctic anticyclones and, in turn, seasonal circulation anomalies, which are of key importance for understanding the variability of summertime Arctic sea-ice melting. © 2018 The Author(s). Citation statistics:
资源类型: 期刊论文
标识符: http://119.78.100.158/handle/2HF3EXSE/105614
Appears in Collections: 气候减缓与适应 科学计划与规划
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作者单位: Institute for Atmospheric and Climate Science, ETH Zurich, Switzerland; Geophysical Institute, University of Bergen and Bjerknes Centre for Climate Research, Bergen, Norway
Recommended Citation:
Wernli H.,Papritz L.. Role of polar anticyclones and mid-latitude cyclones for Arctic summertime sea-ice melting[J]. Nature Geoscience,2018-01-01,11(2)