DOI: 10.1016/j.gloplacha.2017.04.001
论文题名: Modeling 400–500-kyr Pleistocene carbon isotope cyclicity through variations in the dissolved organic carbon pool
作者: Ma W. ; Wang P. ; Tian J.
刊名: Global and Planetary Change
ISSN: 0921-8181
出版年: 2017
卷: 152 起始页码: 187
结束页码: 198
语种: 英语
Scopus关键词: Dissolution
; Isotopes
; Lakes
; Nutrients
; Stream flow
; Weathering
; Chemical weathering
; Computationally efficient
; Dissolved inorganic carbon
; Dissolved organic carbon
; Intermediate complexity
; Mass conservation
; Microbial process
; Transient simulation
; Organic carbon
英文摘要: The carbon isotope (δ13C) record from the Plio-Pleistocene shows prominent 400-kyr cycles with maximum values at eccentricity minima during the Pliocene. The period extends to 500kyr in the Pleistocene after ~1.6Ma. Five δ13C maxima occurred at ~0.2, 0.5, 1.0, 1.5 and 1.9Ma over the last 2Ma. Although several hypotheses have been suggested to explain why the 400–500-kyr cycles are so strong in δ13C records and how they may have originated, the mechanism is still not clear. The aim of this study was to test the dissolved organic carbon (DOC) hypothesis, which was proposed recently to explain this 400–500-kyr cycle in deeper time. We used an intermediate complexity box model that is computationally efficient for studies involving longer timescales. The model incorporates sophisticated microbial processes, dividing the oceanic carbon cycle into a rapid and a slow cycle. The model result suggests that when more nutrients enter the surface ocean, the rapid carbon cycle is more active, and less refractory DOC (RDOC) is produced. The opposite sequence occurs when fewer nutrients enter the ocean. The modeled RDOC concentration and the δ13C of dissolved inorganic carbon (DIC) are anti-correlated with riverine nutrient input. According to mass conservation, the release of isotopically lighter carbon from the RDOC pool leads to lighter DIC δ13C while an increase in the RDOC pool enriches it. The transient simulations produced a one-to-one correspondence between modeled and measured δ13C. This study supports the hypothesis that chemical weathering-induced variations in the DOC pool act as a pacemaker for δ13C changes over 400–500-kyr cycles. © 2017 Elsevier B.V. URL: https://www.scopus.com/inward/record.uri?eid=2-s2.0-85017179851&doi=10.1016%2fj.gloplacha.2017.04.001&partnerID=40&md5=33df591a9e3241f79dc5ef838664247e
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资源类型: 期刊论文
标识符: http://119.78.100.158/handle/2HF3EXSE/11738
Appears in Collections: 全球变化的国际研究计划 气候变化与战略
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作者单位: State Key Laboratory of Marine Geology, Tongji University, Shanghai, China
Recommended Citation:
Ma W.,Wang P.,Tian J.. Modeling 400–500-kyr Pleistocene carbon isotope cyclicity through variations in the dissolved organic carbon pool[J]. Global and Planetary Change,2017-01-01,152.