气候变化领域集成服务门户(CCPortal): Impact of multidecadal variability in Atlantic SST on winter atmospheric blocking

CCPortal

DOI	10.1175/JCLI-D-19-0324.1
	Impact of multidecadal variability in Atlantic SST on winter atmospheric blocking
	Kwon Y.-O.; Seo H.; Ummenhofer C.C.; Joyce T.M.
发表日期	2020
ISSN	0894-8755
起始页码	867
结束页码	892
卷号	33 期号:3
英文摘要	Recent studies have suggested that coherent multidecadal variability exists between North Atlantic atmospheric blocking frequency and the Atlantic multidecadal variability (AMV). However, the role of AMV in modulating blocking variability on multidecadal times scales is not fully understood. This study examines this issue primarily using the NOAA Twentieth Century Reanalysis for 1901-2010. The second mode of the empirical orthogonal function for winter (December-March) atmospheric blocking variability in the North Atlantic exhibits oppositely signed anomalies of blocking frequency over Greenland and the Azores. Furthermore, its principal component time series shows a dominant multidecadal variability lagging AMV by several years. Composite analyses show that this lag is due to the slow evolution of the AMV sea surface temperature (SST) anomalies, which is likely driven by the ocean circulation. Following the warm phase of AMV, the warm SST anomalies emerge in the western subpolar gyre over 3-7 years. The ocean-atmosphere interaction over these 3-7-yr periods is characterized by the damping of the warm SST anomalies by the surface heat flux anomalies, which in turn reduce the overall meridional gradient of the air temperature and thus weaken the meridional transient eddy heat flux in the lower troposphere. The anomalous transient eddy forcing then shifts the eddy-driven jet equatorward, resulting in enhanced Rossby wave breaking and blocking on the northern flank of the jet over Greenland. The opposite is true with the AMV cold phases but with much shorter lags, as the evolution of SST anomalies differs in the warm and cold phases. © 2019 American Meteorological Society. For information regarding reuse of this content and general copyright information, consult the AMS Copyright Policy (www.ametsoc.org/PUBSReuseLicenses).
英文关键词	Atmospheric temperature; Heat flux; Mechanical waves; Orthogonal functions; Surface waters; Atmospheric blocking; Empirical Orthogonal Function; Meridional gradients; Multidecadal variability; Ocean-atmosphere interactions; Principal Components; Sea surface temperature anomalies; Surface heat fluxes; Oceanography; atmospheric blocking; decadal variation; Rossby wave; sea surface temperature; temperature anomaly; wave breaking; winter; Arctic; Atlantic Ocean; Atlantic Ocean (North); Azores; Greenland; Portugal
语种	英语
来源期刊	Journal of Climate
文献类型	期刊论文
条目标识符	http://gcip.llas.ac.cn/handle/2XKMVOVA/171470
作者单位	Woods Hole Oceanographic Institution, Woods Hole, MA, United States
推荐引用方式 GB/T 7714	Kwon Y.-O.,Seo H.,Ummenhofer C.C.,et al. Impact of multidecadal variability in Atlantic SST on winter atmospheric blocking[J],2020,33(3).
APA	Kwon Y.-O.,Seo H.,Ummenhofer C.C.,&Joyce T.M..(2020).Impact of multidecadal variability in Atlantic SST on winter atmospheric blocking.Journal of Climate,33(3).
MLA	Kwon Y.-O.,et al."Impact of multidecadal variability in Atlantic SST on winter atmospheric blocking".Journal of Climate 33.3(2020).