DOI: 10.1175/JCLI-D-18-0040.1
Scopus记录号: 2-s2.0-85052935529
论文题名: Changes in atmospheric blocking circulations linked with winter Arctic warming: A new perspective
作者: Luo D. ; Chen X. ; Dai A. ; Simmonds I.
刊名: Journal of Climate
ISSN: 8948755
出版年: 2018
卷: 31, 期: 18 起始页码: 7661
结束页码: 7678
语种: 英语
英文关键词: Arctic
; Blocking
; Dispersion
Scopus关键词: Dispersion (waves)
; Sea ice
; Arctic
; Atmospheric blocking
; Blocking
; Energy dispersions
; Observational analysis
; Potential vorticity gradients
; Relative vorticity
; Sea ice concentration
; Vorticity
英文摘要: Winter atmospheric blocking circulations such as Ural blocking (UB) have been recognized to play an important role in recent winter Eurasian cooling. Observational analyses performed here reveal that the winter warming in the Barents-Kara Seas (BKS) related to the recent decline of sea ice concentration (SIC) has been accompanied by a large increase in the mean duration of the UB events. A new energy dispersion index (EDI) is designed to help reveal the physics behind this association and show how the BKS warming can influence the mean duration of UB events. This EDI mainly reflects the role of the meridional potential vorticity (PV) gradient in the blocking persistence and it characterizes the changes in energy dispersion and nonlinearity strength of blocking. The meridional PV gradient combines the relative vorticity gradient (related to the nonuniform meridional shear of the mean zonal wind) and the mean zonal wind strength. It is revealed that the BKS warming leads to a significant lengthening of the UB duration because of weakened energy dispersion and intensified nonlinearity of the UB through reduced meridional PV gradient. Furthermore, the duration of the UB is found to depend more strongly on the meridional PV gradient than the mean westerly wind strength, although the meridional PV gradient includes the effect of mean westerly wind strength. Thus, the meridional PV gradient is a better indicator of the change in the blocking duration related to Arctic warming than the zonal wind strength index. © 2018 American Meteorological Society.
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资源类型: 期刊论文
标识符: http://119.78.100.158/handle/2HF3EXSE/110702
Appears in Collections: 影响、适应和脆弱性 气候变化事实与影响
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作者单位: Key Laboratory of Regional Climate-Environment for Temperate East Asia, Institute of Atmospheric Physics, Chinese Academy of Sciences, Beijing, China; Department of Atmospheric and Environmental Sciences, University at Albany, State University of New York, Albany, NY, United States; School of Earth Sciences, University of Melbourne, Melbourne, VIC, Australia
Recommended Citation:
Luo D.,Chen X.,Dai A.,et al. Changes in atmospheric blocking circulations linked with winter Arctic warming: A new perspective[J]. Journal of Climate,2018-01-01,31(18)