气候变化领域集成服务门户(CCPortal): Stability of the Atlantic overturning circulation under intermediate (MIS3) and full glacial (LGM) conditions and its relationship with Dansgaard-Oeschger climate variability

CCPortal

DOI	10.1016/j.quascirev.2020.106443
	Stability of the Atlantic overturning circulation under intermediate (MIS3) and full glacial (LGM) conditions and its relationship with Dansgaard-Oeschger climate variability
	Zhang X.; Prange M.
发表日期	2020
ISSN	0277-3791
卷号	242
英文摘要	Paleoclimatic records reveal that millennial-scale climate variability during the Pleistocene was most pronounced during intermediate glacial conditions, like Marine Isotope Stage 3 (MIS3), rather than during interglacial and fully glaciated climates, like the Last Glacial Maximum (LGM). The rapid transitions between cold stadials and warm interstadials recorded in Greenland ice cores during MIS3, referred to as Dansgaard–Oeschger (D-O) events, have been correlated with millennial-scale climate variations worldwide. Although the origin of D-O events is a matter of controversy, striking evidence shows that variations in the strength of the Atlantic meridional overturning circulation (AMOC) were involved. Therefore, understanding the stability properties of the ocean circulation under different background climate conditions is key to understanding D-O millennial-scale climate variability. In the present study, the stability of the AMOC to northern high-latitude freshwater perturbations under MIS3 and LGM boundary conditions is investigated by using the coupled climate model CCSM3. Stability diagrams constructed from a large set of equilibrium experiments reveal a nonlinear dependence of AMOC strength on freshwater forcing under both MIS3 and LGM conditions. The MIS3 baseline state is close to an AMOC stability threshold, which makes the MIS3 climate unstable with respect to minor perturbations. A similar threshold behavior in AMOC stability is observed under LGM conditions; however, larger freshwater perturbations are necessary to pass the threshold and weaken the AMOC. The threshold's displacement relative to the MIS3 background climate is attributable to differences in the atmospheric hydrologic cycle and North Atlantic sea ice transport. Different atmospheric moisture transports are attributable to thermodynamic and dynamic processes related to differences in greenhouse gas forcing and ice-sheet height between MIS3 and the LGM. We conclude that the higher stability of the AMOC during the LGM is a physically plausible explanation for millennial-scale D-O-type climate variability being suppressed under full glacial conditions, whereas minor perturbations in freshwater fluxes could have triggered D-O climate shifts during MIS3. © 2020 Elsevier Ltd
英文关键词	Abrupt climate change; Atlantic meridional overturning circulation; Dansgaard-Oeschger events; Last glacial maximum; Marine isotope stage 3; Paleoclimate modeling
语种	英语
scopus关键词	Atmospheric movements; Climatology; Glacial geology; Greenhouse gases; Oceanography; Sea ice; Stability; Water; Atlantic meridional overturning circulations; Atmospheric hydrologic cycle; Atmospheric moisture; Coupled climate model; Greenhouse-gas forcing; Marine isotope stages; Overturning circulation; Paleoclimatic record; Climate models; climate conditions; climate modeling; climate variation; Dansgaard-Oeschger cycle; ice core; interglacial; Last Glacial Maximum; marine isotope stage; meridional circulation; oceanic circulation; paleoclimate; Pleistocene; Arctic; Atlantic Ocean; Atlantic Ocean (North); Greenland
来源期刊	Quaternary Science Reviews
文献类型	期刊论文
条目标识符	http://gcip.llas.ac.cn/handle/2XKMVOVA/151396
作者单位	Nanjing University of Information Science and Technology, China; MARUM – Center for Marine Environmental Sciences, University of Bremen, Germany
推荐引用方式 GB/T 7714	Zhang X.,Prange M.. Stability of the Atlantic overturning circulation under intermediate (MIS3) and full glacial (LGM) conditions and its relationship with Dansgaard-Oeschger climate variability[J],2020,242.
APA	Zhang X.,&Prange M..(2020).Stability of the Atlantic overturning circulation under intermediate (MIS3) and full glacial (LGM) conditions and its relationship with Dansgaard-Oeschger climate variability.Quaternary Science Reviews,242.
MLA	Zhang X.,et al."Stability of the Atlantic overturning circulation under intermediate (MIS3) and full glacial (LGM) conditions and its relationship with Dansgaard-Oeschger climate variability".Quaternary Science Reviews 242(2020).