气候变化领域集成服务门户(CCPortal): Simulating Marine Isotope Stage 7 with a coupled climate-ice sheet model

CCPortal

DOI	10.5194/cp-16-2183-2020
	Simulating Marine Isotope Stage 7 with a coupled climate-ice sheet model
	Choudhury D.; Timmermann A.; Schloesser F.; Heinemann M.; Pollard D.
发表日期	2020
ISSN	18149324
起始页码	2183
结束页码	2201
卷号	16 期号:6
英文摘要	It is widely accepted that orbital variations are responsible for the generation of glacial cycles during the late Pleistocene. However, the relative contributions of the orbital forcing compared to CO2 variations and other feedback mechanisms causing the waxing and waning of ice sheets have not been fully understood. Testing theories of ice ages beyond statistical inferences, requires numerical modeling experiments that capture key features of glacial transitions. Here, we focus on the glacial buildup from Marine Isotope Stage (MIS) 7 to 6 covering the period from 240 to 170 ka (ka: thousand years before present). This transition from interglacial to glacial conditions includes one of the fastest Pleistocene glaciation-deglaciation events, which occurred during MIS 7e-7d-7c (236-218 ka). Using a newly developed three-dimensional coupled atmosphere-ocean-vegetation-ice sheet model (LOVECLIP), we simulate the transient evolution of Northern Hemisphere and Southern Hemisphere ice sheets during the MIS 7-6 period in response to orbital and greenhouse gas forcing. For a range of model parameters, the simulations capture the evolution of global ice volume well within the range of reconstructions. Over the MIS 7-6 period, it is demonstrated that glacial inceptions are more sensitive to orbital variations, whereas terminations from deep glacial conditions need both orbital and greenhouse gas forcings to work in unison. For some parameter values, the coupled model also exhibits a critical North American ice sheet configuration, beyond which a stationary-wave-ice-sheet topography feedback can trigger an unabated and unrealistic ice sheet growth. The strong parameter sensitivity found in this study originates from the fact that delicate mass imbalances, as well as errors, are integrated during a transient simulation for thousands of years. This poses a general challenge for transient coupled climate-ice sheet modeling, with such coupled paleo-simulations providing opportunities to constrain such parameters. © 2020 Author(s).
语种	英语
scopus关键词	carbon dioxide; climate modeling; climate variation; glacial-interglacial cycle; ice sheet; marine isotope stage; orbital forcing; Southern Hemisphere
来源期刊	Climate of the Past
文献类型	期刊论文
条目标识符	http://gcip.llas.ac.cn/handle/2XKMVOVA/153179
作者单位	Center for Climate Physics, Institute for Basic Science (IBS), Busan, 46241, South Korea; Pusan National University, Busan, 46241, South Korea; International Pacific Research Center, University of Hawaii at Manoa, Honolulu, HI 96822, United States; Institute of Geosciences, Kiel University, Kiel, 24118, Germany; Earth and Environmental Systems Institute, Pennsylvania State University, University Park, PA 16802, United States
推荐引用方式 GB/T 7714	Choudhury D.,Timmermann A.,Schloesser F.,et al. Simulating Marine Isotope Stage 7 with a coupled climate-ice sheet model[J],2020,16(6).
APA	Choudhury D.,Timmermann A.,Schloesser F.,Heinemann M.,&Pollard D..(2020).Simulating Marine Isotope Stage 7 with a coupled climate-ice sheet model.Climate of the Past,16(6).
MLA	Choudhury D.,et al."Simulating Marine Isotope Stage 7 with a coupled climate-ice sheet model".Climate of the Past 16.6(2020).