气候变化领域集成服务门户(CCPortal): The Pacific Meridional Mode over the last millennium

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DOI	10.1007/s00382-019-04740-1
	The Pacific Meridional Mode over the last millennium
	Sanchez S.C.; Amaya D.J.; Miller A.J.; Xie S.-P.; Charles C.D.
发表日期	2019
ISSN	0930-7575
起始页码	3547
结束页码	3560
卷号	53 期号:2020-05-06
英文摘要	The Pacific Meridional Mode, a coupled ocean–atmospheric interaction responsible for propagating subtropical anomalies to the tropics via thermodynamic mechanisms, features prominently in discussions of the response of climate variability to climate change. However, it is presently unclear how and why the variance in PMM might change, or even if greenhouse gas forcing might lead to heightened activity. Here, PMM variance over the last millennium is assessed in the Community Earth System Model Last Millennium Ensemble (LME). The model reproduces the main spatial characteristics of the PMM in the modern ocean in agreement with observations. With this basis, we assess the magnitude of the PMM variance over the past millennium, subject to forcing from a variety of sources. Internal (unforced) variability dominates the PMM variance in the LME, but prolonged periods of strong or weak PMM variance are found to be associated with characteristic spatial patterns, consistent across ensemble members and forcing experiments. The pattern of strong PMM variance features a cooler north Pacific, weaker Walker circulation, and a southward-shifted ITCZ. Comparison with a slab ocean model suggests that equatorial ocean dynamics are necessary to sustain the statistically significant multidecadal variability. With respect to the last millennium, present greenhouse forcing does not promote exceptional PMM variance. However, the PMM variability projected in the RCP8.5 scenario exceeds the thresholds expressed with the forcings applied over the Last Millennium. Aside from multidecadal variability, the model simulations also bear on ENSO variability and the sensitivity of climate variability to external forcing. © 2019, Springer-Verlag GmbH Germany, part of Springer Nature.
英文关键词	Decadal climate variability; ENSO; Last millennium; Pacific Meridional Mode (PMM); Paleoclimate
语种	英语
scopus关键词	air-sea interaction; computer simulation; decadal variation; El Nino-Southern Oscillation; meridional circulation; numerical model; paleoclimate
来源期刊	Climate Dynamics
文献类型	期刊论文
条目标识符	http://gcip.llas.ac.cn/handle/2XKMVOVA/146005
作者单位	Joint Institute for the Study of the Atmosphere and Ocean, University of Washington, Seattle, WA 98195, United States; Scripps Institution of Oceanography, University of California-San Diego, La Jolla, CA 92037, United States
推荐引用方式 GB/T 7714	Sanchez S.C.,Amaya D.J.,Miller A.J.,et al. The Pacific Meridional Mode over the last millennium[J],2019,53(2020-05-06).
APA	Sanchez S.C.,Amaya D.J.,Miller A.J.,Xie S.-P.,&Charles C.D..(2019).The Pacific Meridional Mode over the last millennium.Climate Dynamics,53(2020-05-06).
MLA	Sanchez S.C.,et al."The Pacific Meridional Mode over the last millennium".Climate Dynamics 53.2020-05-06(2019).