气候变化领域集成服务门户(CCPortal): Simulating the climate response to atmospheric oxygen variability in the Phanerozoic: A focus on the Holocene; Cretaceous and Permian

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DOI	10.5194/cp-15-1463-2019
	Simulating the climate response to atmospheric oxygen variability in the Phanerozoic: A focus on the Holocene; Cretaceous and Permian
	Wade D.C.; Luke Abraham N.; Farnsworth A.; Valdes P.J.; Bragg F.; Archibald A.T.
发表日期	2019
ISSN	18149324
起始页码	1463
结束页码	1483
卷号	15 期号:4
英文摘要	The amount of dioxygen (O2) in the atmosphere may have varied from as little as 5% to as much as 35% during the Phanerozoic eon (54 Ma-present). These changes in the amount of O2 are large enough to have led to changes in atmospheric mass, which may alter the radiative budget of the atmosphere, leading to this mechanism being invoked to explain discrepancies between climate model simulations and proxy reconstructions of past climates. Here, we present the first fully 3-D numerical model simulations to investigate the climate impacts of changes in O2 under different climate states using the coupled atmosphere-ocean Hadley Centre Global Environmental Model version 3 (HadGEM3-AO) and Hadley Centre Coupled Model version 3 (HadCM3-BL) models.We show that simulations with an increase in O2 content result in increased global-mean surface air temperature under conditions of a pre-industrial Holocene climate state, in agreement with idealised 1-D and 2-D modelling studies. We demonstrate the mechanism behind the warming is complex and involves a trade-off between a number of factors. Increasing atmospheric O2 leads to a reduction in incident shortwave radiation at the Earth's surface due to Rayleigh scattering, a cooling effect. However, there is a competing warming effect due to an increase in the pressure broadening of greenhouse gas absorption lines and dynamical feedbacks, which alter the meridional heat transport of the ocean, warming polar regions and cooling tropical regions. Case studies from past climates are investigated using HadCM3-BL and show that, in the warmest climate states in the Maastrichtian (72.1-66.0 Ma), increasing oxygen may lead to a temperature decrease, as the equilibrium climate sensitivity is lower. For the Asselian (298.9-295.0 Ma), increasing oxygen content leads to a warmer global-mean surface temperature and reduced carbon storage on land, suggesting that high oxygen content may have been a contributing factor in preventing a "Snowball Earth" during this period of the early Permian. These climate model simulations reconcile the surface temperature response to oxygen content changes across the hierarchy of model complexity and highlight the broad range of Earth system feedbacks that need to be accounted for when considering the climate response to changes in atmospheric oxygen content. © 2019 Author(s). This work is distributed under the Creative Commons Attribution 4.0 License.
语种	英语
scopus关键词	air temperature; carbon sequestration; climate effect; Cretaceous; global warming; Holocene; numerical model; oxygen; paleoclimate; Permian; Phanerozoic; shortwave radiation; simulation; three-dimensional modeling
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/146789
作者单位	Department of Chemistry, Centre for Atmospheric Science, Cambridge, United Kingdom; Department of Chemistry, National Centre for Atmospheric Science, Cambridge, United Kingdom; School of Geographical Sciences, University of Bristol, Bristol, United Kingdom
推荐引用方式 GB/T 7714	Wade D.C.,Luke Abraham N.,Farnsworth A.,et al. Simulating the climate response to atmospheric oxygen variability in the Phanerozoic: A focus on the Holocene; Cretaceous and Permian[J],2019,15(4).
APA	Wade D.C.,Luke Abraham N.,Farnsworth A.,Valdes P.J.,Bragg F.,&Archibald A.T..(2019).Simulating the climate response to atmospheric oxygen variability in the Phanerozoic: A focus on the Holocene; Cretaceous and Permian.Climate of the Past,15(4).
MLA	Wade D.C.,et al."Simulating the climate response to atmospheric oxygen variability in the Phanerozoic: A focus on the Holocene; Cretaceous and Permian".Climate of the Past 15.4(2019).