DOI: 10.1007/s00382-013-1920-8
Scopus记录号: 2-s2.0-84906091466
论文题名: Critical mechanisms for the formation of extreme arctic sea-ice extent in the summers of 2007 and 1996
作者: Dong X. ; Zib B.J. ; Xi B. ; Stanfield R. ; Deng Y. ; Zhang X. ; Lin B. ; Long C.N.
刊名: Climate Dynamics
ISSN: 9307575
出版年: 2014
卷: 43, 期: 2017-01-02 起始页码: 53
结束页码: 70
语种: 英语
英文关键词: Cloud-radiation-water vapor feedback to the sea-ice-concentration variation
; Enhanced clouds-radiation-PWV feedback
; Extreme Arctic sea-ice extent formation mechanisms
; Trigger and cause of Arctic sea ice retreat
; Triggered by atmospheric forcings
英文摘要: Along with significant changes in the Arctic climate system, the largest year-to-year variation in sea-ice extent (SIE) has occurred in the Laptev, East Siberian, and Chukchi seas (defined here as the area of focus, AOF), among which the two highly contrasting extreme events were observed in the summers of 2007 and 1996 during the period 1979-2012. Although most efforts have been devoted to understanding the 2007 low, a contrasting high September SIE in 1996 might share some related but opposing forcing mechanisms. In this study, we investigate the mechanisms for the formation of these two extremes and quantitatively estimate the cloud-radiation-water vapor feedback to the sea-ice-concentration (SIC) variation utilizing satellite-observed sea-ice products and the NASA MERRA reanalysis. The low SIE in 2007 was associated with a persistent anticyclone over the Beaufort Sea coupled with low pressure over Eurasia, which induced anomalous southerly winds. Ample warm and moist air from the North Pacific was transported to the AOF and resulted in positive anomalies of cloud fraction (CF), precipitable water vapor (PWV), surface LWnet (down-up), total surface energy and temperature. In contrast, the high SIE event in 1996 was associated with a persistent low pressure over the central Arctic coupled with high pressure along the Eastern Arctic coasts, which generated anomalous northerly winds and resulted in negative anomalies of above mentioned atmospheric parameters. In addition to their immediate impacts on sea ice reduction, CF, PWV and radiation can interplay to lead to a positive feedback loop among them, which plays a critical role in reinforcing sea ice to a great low value in 2007. During the summer of 2007, the minimum SIC is 31 % below the climatic mean, while the maximum CF, LWnet and PWV can be up to 15 %, 20 Wm-2, and 4 kg m-3 above. The high anti-correlations (-0.79, -0.61, -0.61) between the SIC and CF, PWV, and LWnet indicate that CF, PWV and LW radiation are indeed having significant impacts on the SIC variation. A new record low occurred in the summer of 2012 was mainly triggered by a super storm over the central Arctic Ocean in early August that caused substantial mechanical ice deformation on top of the long-term thinning of an Arctic ice pack that had become more dominated by seasonal ice. © 2013 The Author(s). 资助项目: DOE, National Science Foundation
; EPSCoR, National Science Foundation
; NASA, National Science Foundation
; NSF, National Science Foundation
; NSF, National Science Foundation
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资源类型: 期刊论文
标识符: http://119.78.100.158/handle/2HF3EXSE/54675
Appears in Collections: 过去全球变化的重建
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作者单位: GCESS, Beijing Normal University, Beijing, China; The Department of Atmospheric Sciences, University of North Dakota, 4149 University Ave. Stop 9006, Grand Forks, ND, 58202-9006, United States; School of Earth and Atmospheric Sciences, Georgia Institute of Technology, Atlanta, GA, United States; Department of Atmospheric Sciences, International Arctic Research Center, University of Alaska Fairbank, Fairbank, AK, United States; NASA Langley Research Center, Hampton, VA, United States; DOE Pacific Northwest National Laboratory, Richland, WA, United States
Recommended Citation:
Dong X.,Zib B.J.,Xi B.,et al. Critical mechanisms for the formation of extreme arctic sea-ice extent in the summers of 2007 and 1996[J]. Climate Dynamics,2014-01-01,43(2017-01-02)