气候变化领域集成服务门户(CCPortal): Evidence for a volcanic underpinning of the Atlantic multidecadal oscillation

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DOI	10.1038/s41612-018-0036-6
	Evidence for a volcanic underpinning of the Atlantic multidecadal oscillation
	Birkel S.D.; Mayewski P.A.; Maasch K.A.; Kurbatov A.V.; Lyon B.
发表日期	2018
ISSN	23973722
卷号	1 期号:1
英文摘要	The Atlantic multidecadal oscillation (AMO) is a 60–70 year pattern of sea-surface temperature (SST) variability in the North Atlantic commonly ascribed to internal ocean dynamics and changes in northward heat transport. Recent modeling studies, however, suggest that SSTs fluctuate primarily in response to major volcanic eruptions and changes in atmospheric circulation. Here, we utilize historical SST, atmospheric reanalysis, and stratospheric aerosol optical depth data to examine the basic evidence supporting a volcanic link. We find that cool intervals across the North Atlantic coincide with two distinct episodes of explosive volcanic activity (1880s–1920s and 1960s–1990s), where key eruptions include 1883 Krakatau, 1902 Santa María, 1912 Novarupta, 1963 Agung, 1982 El Chichón, and 1991 Pinatubo. Cool SST patterns develop in association with an increased prevalence of North Atlantic Oscillation (NAO)+ atmospheric patterns caused by stratospheric aerosol loading and a steepened poleward temperature gradient. NAO+ patterns promote wind-driven advection, evaporative cooling, and increased albedo from enhanced Saharan dust transport and anthropogenic aerosols. SSTs across the subpolar gyre are regulated by strength of low pressure near Iceland and the associated wind-driven advection of cold surface water from the Labrador Sea. This is contrary to an interpretation that subpolar SSTs are driven by changes in ocean overturning circulation. We also find that North Pacific and global mean SST declines can be readily associated with the same volcanic triggers that affect the North Atlantic. Thus, external forcing from volcanic aerosols appears to underpin multi-decade SST variability observed in the historical record. © 2018, The Author(s).
语种	英语
scopus关键词	aerosol; Atlantic Multidecadal Oscillation; atmospheric circulation; heat transfer; sea surface temperature; volcanic eruption; Atlantic Ocean; Atlantic Ocean (North)
来源期刊	npj Climate and Atmospheric Science
文献类型	期刊论文
条目标识符	http://gcip.llas.ac.cn/handle/2XKMVOVA/178163
作者单位	Climate Change Institute and School of Earth and Climate Sciences, University of Maine, Orono, ME, United States
推荐引用方式 GB/T 7714	Birkel S.D.,Mayewski P.A.,Maasch K.A.,et al. Evidence for a volcanic underpinning of the Atlantic multidecadal oscillation[J],2018,1(1).
APA	Birkel S.D.,Mayewski P.A.,Maasch K.A.,Kurbatov A.V.,&Lyon B..(2018).Evidence for a volcanic underpinning of the Atlantic multidecadal oscillation.npj Climate and Atmospheric Science,1(1).
MLA	Birkel S.D.,et al."Evidence for a volcanic underpinning of the Atlantic multidecadal oscillation".npj Climate and Atmospheric Science 1.1(2018).