气候变化领域集成服务门户(CCPortal): Mechanisms of millennial-scale atmospheric CO2 change in numerical model simulations

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DOI	10.1016/j.quascirev.2019.05.013
	Mechanisms of millennial-scale atmospheric CO2 change in numerical model simulations
	Gottschalk J.; Battaglia G.; Fischer H.; Frölicher T.L.; Jaccard S.L.; Jeltsch-Thömmes A.; Joos F.; Köhler P.; Meissner K.J.; Menviel L.; Nehrbass-Ahles C.; Schmitt J.; Schmittner A.; Skinner L.C.; Stocker T.F.
发表日期	2019
ISSN	0277-3791
起始页码	30
结束页码	74
卷号	220
英文摘要	Numerical models are important tools for understanding the processes and feedbacks in the Earth system, including those involving changes in atmospheric CO2 (CO2,atm) concentrations. Here, we compile 55 published model studies (consisting of 778 individual simulations) that assess the impact of six forcing mechanisms on millennial-scale CO2,atm variations: changes in freshwater supply to the North Atlantic and Southern Ocean, the strength and position of the southern-hemisphere westerlies, Antarctic sea ice extent, and aeolian dust fluxes. We generally find agreement on the direction of simulated CO2,atm change across simulations, but the amplitude of change is inconsistent, primarily due to the different complexities of the model representation of Earth system processes. When freshwater is added to the North Atlantic, a reduced Atlantic Meridional Overturning Circulation (AMOC) is generally accompanied by an increase in Southern Ocean- and Pacific overturning, reduced Antarctic sea ice extent, spatially varying export production, and changes in carbon storage in the Atlantic (rising), in other ocean basins (generally decreasing) and on land (more varied). Positive or negative CO2,atm changes are simulated during AMOC minima due to a spatially and temporally varying dominance of individual terrestrial and oceanic drivers (and compensating effects between them) across the different models. In contrast, AMOC recoveries are often accompanied by rising CO2,atm levels, which are mostly driven by ocean carbon release (albeit from different regions). The magnitude of simulated CO2,atm rise broadly scales with the duration of the AMOC perturbation (i.e., the stadial length). When freshwater is added to the Southern Ocean, reduced deep-ocean ventilation drives a CO2,atm drop via reduced carbon release from the Southern Ocean. Although the impacts of shifted southern-hemisphere westerlies are inconsistent across model simulations, their intensification raises CO2,atm via enhanced Southern Ocean Ekman pumping. Increased supply of aeolian dust to the ocean, and thus iron fertilisation of marine productivity, consistently lowers modelled CO2,atm concentrations via more efficient nutrient utilisation. The magnitude of CO2,atm change in response to dust flux variations, however, largely depends on the complexity of models' marine ecosystem and iron cycle. This especially applies to simulations forced by Antarctic sea ice changes, in which the direction of simulated CO2,atm change varies greatly across model hierarchies. Our compilation highlights that no single (forcing) mechanism can explain observed past millennial-scale CO2,atm variability, and identifies important future needs in coupled carbon cycle-climate modelling to better understand the mechanisms governing CO2,atm changes in the past. © 2019 The Authors
英文关键词	Atmospheric CO2 variations; Carbon cycle; Dust; Freshwater hosing; Palaeoclimate modelling; Sea ice; Southern-hemisphere westerlies
语种	英语
scopus关键词	Carbon dioxide; Dust; Ecosystems; Iron; Numerical models; Sea ice; Water; Atlantic meridional overturning circulations; Carbon cycles; Freshwater hosing; Marine productivity; Model representation; Numerical model simulations; Palaeoclimate; Southern Hemisphere; Oceanography; air-soil interaction; air-water interaction; carbon cycle; carbon dioxide; climate modeling; dust; Ekman pumping; eolian deposit; Kimmeridgian; marine ecosystem; meridional circulation; numerical model; paleoclimate; sea ice; simulation; Southern Hemisphere; terrestrial environment; westerly; Atlantic Ocean; Atlantic Ocean (North); Pacific Ocean; Southern Ocean
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/151812
作者单位	Institute of Geological Sciences and Oeschger Center for Climate Change Research, University of Bern, Bern, Switzerland; Lamont-Doherty Earth Observatory of Columbia University, Palisades, NY, United States; Climate and Environmental Physics, Physics Institute, and Oeschger Center for Climate Change Research, University of Bern, Bern, Switzerland; Alfred-Wegener-Institut, Helmholtz-Zentrum für Polar- und Meeresforschung, Bremerhaven, Germany; Climate Change Research Centre, University of New South Wales, Sydney, Australia; ARC Centre of Excellence for Climate Extremes, Australia; Godwin Laboratory for Palaeoclimate Research, Earth Sciences Department, University of Cambridge, Cambridge, United Kingdom; College of Earth, Ocean, and Atmospheric Sciences, Oregon State University, Corvallis, OR, United States
推荐引用方式 GB/T 7714	Gottschalk J.,Battaglia G.,Fischer H.,et al. Mechanisms of millennial-scale atmospheric CO2 change in numerical model simulations[J],2019,220.
APA	Gottschalk J..,Battaglia G..,Fischer H..,Frölicher T.L..,Jaccard S.L..,...&Stocker T.F..(2019).Mechanisms of millennial-scale atmospheric CO2 change in numerical model simulations.Quaternary Science Reviews,220.
MLA	Gottschalk J.,et al."Mechanisms of millennial-scale atmospheric CO2 change in numerical model simulations".Quaternary Science Reviews 220(2019).