气候变化领域集成服务门户(CCPortal): Observed statistical connections overestimate the causal effects of arctic sea ice changes on midlatitude winter climate

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DOI	10.1175/JCLI-D-20-0293.1
	Observed statistical connections overestimate the causal effects of arctic sea ice changes on midlatitude winter climate
	Blackport R.; Screen J.A.
发表日期	2021
ISSN	08948755
起始页码	3021
结束页码	3038
卷号	34 期号:8
英文摘要	Disentangling the contribution of changing Arctic sea ice to midlatitude winter climate variability remains challenging because of the large internal climate variability in midlatitudes, difficulties separating cause from effect, methodological differences, and uncertainty around whether models adequately simulate connections between Arctic sea ice and midlatitude climate. We use regression analysis to quantify the links between Arctic sea ice and midlatitude winter climate in observations and large initial-condition ensembles of multiple climate models, in both coupled configurations and so-called Atmospheric Model Intercomparison Project (AMIP) configurations, where observed sea ice and/or sea surface temperatures are prescribed. The coupled models capture the observed links in interannual variability between winter Barents-Kara sea ice and Eurasian surface temperature, and between winter Chukchi-Bering sea ice and North American surface temperature. The coupled models also capture the delayed connection between reduced November-December Barents-Kara sea ice, a weakened winter stratospheric polar vortex, and a shift toward the negative phase of the North Atlantic Oscillation in late winter, although this downward impact is weaker than observed. The strength and sign of the connections both vary considerably between individual 35-yr-long ensemble members, highlighting the need for large ensembles to separate robust connections from internal variability. All the aforementioned links are either absent or are substantially weaker in the AMIP experiments prescribed with only observed sea ice variability. We conclude that the causal effects of sea ice variability on midlatitude winter climate are much weaker than suggested by statistical associations, evident in observations and coupled models, because the statistics are inflated by the effects of atmospheric circulation variability on sea ice. © 2021 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	Arctic; Climate change; Climate models; Climate variability; Sea ice; Teleconnections
语种	英语
scopus关键词	Atmospheric pressure; Atmospheric temperature; Climate change; Oceanography; Sea ice; Surface properties; Surface waters; Atmospheric circulation variability; Atmospheric model intercomparison projects; Initial condition ensembles; Interannual variability; Internal climate variability; North Atlantic oscillations; Sea surface temperature (SST); Stratospheric polar vortex; Climate models; atmosphere-ocean coupling; atmospheric modeling; climate change; climate modeling; climate variation; North Atlantic Oscillation; sea ice; sea surface temperature; teleconnection; winter; Arctic Ocean; Barents Sea; Chukchi Sea; Kara Sea
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/178651
作者单位	College of Engineering, Mathematics, and Physical Sciences, University of Exeter, Exeter, United Kingdom
推荐引用方式 GB/T 7714	Blackport R.,Screen J.A.. Observed statistical connections overestimate the causal effects of arctic sea ice changes on midlatitude winter climate[J],2021,34(8).
APA	Blackport R.,&Screen J.A..(2021).Observed statistical connections overestimate the causal effects of arctic sea ice changes on midlatitude winter climate.Journal of Climate,34(8).
MLA	Blackport R.,et al."Observed statistical connections overestimate the causal effects of arctic sea ice changes on midlatitude winter climate".Journal of Climate 34.8(2021).