DOI: 10.1002/2016GB005425
Scopus记录号: 2-s2.0-85018995038
论文题名: Calculating the balance between atmospheric CO2 drawdown and organic carbon oxidation in subglacial hydrochemical systems
作者: Graly J ; A ; , Drever J ; I ; , Humphrey N ; F
刊名: Global Biogeochemical Cycles
ISSN: 8866236
出版年: 2017
卷: 31, 期: 4 起始页码: 709
结束页码: 727
语种: 英语
英文关键词: carbon cycle
; chemical weathering
; glaciers
; microbial oxidation
; subglacial processes
Scopus关键词: atmospheric gas
; carbon cycle
; carbon dioxide
; carbon flux
; chemical weathering
; drawdown
; glacier
; ice sheet
; microbial activity
; organic carbon
; organic matter
; oxidation
; soil carbon
; subglacial environment
英文摘要: In order to constrain CO2 fluxes from biogeochemical processes in subglacial environments, we model the evolution of pH and alkalinity over a range of subglacial weathering conditions. We show that subglacial waters reach or exceed atmospheric pCO2 levels when atmospheric gases are able to partially access the subglacial environment. Subsequently, closed system oxidation of sulfides is capable of producing pCO2 levels well in excess of atmosphere levels without any input from the decay of organic matter. We compared this model to published pH and alkalinity measurements from 21 glaciers and ice sheets. Most subglacial waters are near atmospheric pCO2 values. The assumption of an initial period of open system weathering requires substantial organic carbon oxidation in only 4 of the 21 analyzed ice bodies. If the subglacial environment is assumed to be closed from any input of atmospheric gas, large organic carbon inputs are required in nearly all cases. These closed system assumptions imply that order of 10 g m−2 y−1 of organic carbon are removed from a typical subglacial environment—a rate too high to represent soil carbon built up over previous interglacial periods and far in excess of fluxes of surface deposited organic carbon. Partial open system input of atmospheric gases is therefore likely in most subglacial environments. The decay of organic carbon is still important to subglacial inorganic chemistry where substantial reserves of ancient organic carbon are found in bedrock. In glaciers and ice sheets on silicate bedrock, substantial long-term drawdown of atmospheric CO2 occurs. ©2017. American Geophysical Union. All Rights Reserved. Citation statistics:
资源类型: 期刊论文
标识符: http://119.78.100.158/handle/2HF3EXSE/77753
Appears in Collections: 气候变化事实与影响
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作者单位: Department of Geology and Geophysics, University of Wyoming, Laramie, WY, United States
Recommended Citation:
Graly J,A,, Drever J,et al. Calculating the balance between atmospheric CO2 drawdown and organic carbon oxidation in subglacial hydrochemical systems[J]. Global Biogeochemical Cycles,2017-01-01,31(4)