DOI: 10.5194/cp-10-1887-2014
Scopus记录号: 2-s2.0-84908315607
论文题名: The role of the northward-directed (sub)surface limb of the Atlantic Meridional Overturning Circulation during the 8.2 ka event
作者: Tegzes A.D. ; Jansen E. ; Telford R.J.
刊名: Climate of the Past
ISSN: 18149324
出版年: 2014
卷: 10, 期: 5 起始页码: 1887
结束页码: 1904
语种: 英语
Scopus关键词: albedo
; climate variation
; heat transfer
; Holocene
; meridional circulation
; outburst
; paleoclimate
; proglacial environment
; Arctic
; Arctic Ocean
; Atlantic Ocean
; Atlantic Ocean (North)
; Canada
; Greenland
; Hudson Bay
; Norwegian Sea
英文摘要: The so-called "8.2 ka event" is widely regarded as a major Holocene climate perturbation. It is most readily identifiable in the oxygen-isotope records from Greenland ice cores as an approximately 160-year-long cold interval between 8250 and 8090 years BP. The prevailing view has been that the cooling over Greenland, and potentially over the northern North Atlantic at least, was triggered by the catastrophic final drainage of the Agassiz-Ojibway proglacial lake as part of the remnant Laurentide Ice Sheet collapsed over Hudson Bay at around 8420 ± 80 years BP. The consequent freshening of surface waters in the northern North Atlantic Ocean and the Nordic Seas resulted in weaker overturning, and hence reduced northward ocean heat transport. We have reconstructed variations in the strength of the eastern branch of the Atlantic Inflow into the Nordic Seas around the time of the lake outbursts. While the initial freshwater forcing may have been even larger than originally thought, as the lake outbursts may have been accompanied by a major iceberg discharge from Hudson Bay, our proxy records from the mid-Norwegian Margin do not evidence a uniquely large slowdown in the eastern branch of the Atlantic Inflow at the time. Therefore, its main role in the 8.2 ka event may have been the (rapid) advection of fresh and cold waters to high northern latitudes, initiating rapid sea-ice expansion and an increase in surface albedo. © 2014 Author(s). Citation statistics:
资源类型: 期刊论文
标识符: http://119.78.100.158/handle/2HF3EXSE/49205
Appears in Collections: 气候变化与战略
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Recommended Citation:
Tegzes A.D.,Jansen E.,Telford R.J.. The role of the northward-directed (sub)surface limb of the Atlantic Meridional Overturning Circulation during the 8.2 ka event[J]. Climate of the Past,2014-01-01,10(5)