气候变化领域集成服务门户(CCPortal): Modeling the evolution of pulse-like perturbations in atmospheric carbon and carbon isotopes: The role of weathering-sedimentation imbalances

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DOI	10.5194/cp-16-423-2020
	Modeling the evolution of pulse-like perturbations in atmospheric carbon and carbon isotopes: The role of weathering-sedimentation imbalances
	Jeltsch-Thömmes A.; Joos F.
发表日期	2020
ISSN	18149324
起始页码	423
结束页码	451
卷号	16 期号:2
英文摘要	Measurements of carbon isotope variations in climate archives and isotope-enabled climate modeling advance the understanding of the carbon cycle. Perturbations in atmospheric CO2 and in its isotopic ratios (δ13C, Δ14C) are removed by different processes acting on different timescales. We investigate these differences on timescales of up to 100 000 years in pulse-release experiments with the Bern3DLPX Earth system model of intermediate complexity and by analytical solutions from a box model. On timescales from years to many centuries, the atmospheric perturbations in CO2 and δ13CO2 are reduced by air-sea gas exchange, physical transport from the surface to the deep ocean, and by the land biosphere. Isotopic perturbations are initially removed much faster from the atmosphere than perturbations in CO2 as explained by aquatic carbonate chemistry. On multimillennial timescales, the CO2 perturbation is removed by carbonate compensation and silicate rock weathering. In contrast, the δ13C perturbation is removed by the relentless flux of organic and calcium carbonate particles buried in sediments. The associated removal rate is significantly modified by spatial δ13C gradients within the ocean, influencing the isotopic perturbation of the burial flux. Space-time variations in ocean δ13C perturbations are captured by principal components and empirical orthogonal functions. Analytical impulse response functions for atmospheric CO2 and δ13CO2 are provided. Results suggest that changes in terrestrial carbon storage were not the sole cause for the abrupt, centennial-scale CO2 and δ13CO2 variations recorded in ice during Heinrich stadials HS1 and HS4, though model and data uncertainties prevent a firm conclusion. The δ13C offset between the Penultimate Glacial Maximum and Last Glacial Maximum reconstructed for the ocean and atmosphere is most likely caused by imbalances between weathering, volcanism, and burial fluxes. Our study highlights the importance of isotopic fluxes connected to weathering-sedimentation imbalances, which so far have been often neglected on glacial-interglacial timescales. © Author(s) 2020.
语种	英语
scopus关键词	burial (geology); calcium carbonate; carbon isotope; carbon storage; climate modeling; isotopic composition; Last Glacial Maximum; paleoclimate; perturbation; proxy climate record; sedimentation; silicate
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/146737
作者单位	Climate and Environmental Physics, Physics Institute and Oeschger Centre for Climate Change Research, University of Bern, Bern, Switzerland
推荐引用方式 GB/T 7714	Jeltsch-Thömmes A.,Joos F.. Modeling the evolution of pulse-like perturbations in atmospheric carbon and carbon isotopes: The role of weathering-sedimentation imbalances[J],2020,16(2).
APA	Jeltsch-Thömmes A.,&Joos F..(2020).Modeling the evolution of pulse-like perturbations in atmospheric carbon and carbon isotopes: The role of weathering-sedimentation imbalances.Climate of the Past,16(2).
MLA	Jeltsch-Thömmes A.,et al."Modeling the evolution of pulse-like perturbations in atmospheric carbon and carbon isotopes: The role of weathering-sedimentation imbalances".Climate of the Past 16.2(2020).