DOI: 10.1002/gbc.20018
Scopus记录号: 2-s2.0-84877955255
论文题名: River discharge influences on particulate organic carbon age structure in the Mississippi/Atchafalaya River System
作者: Rosenheim B ; E ; , Roe K ; M ; , Roberts B ; J ; , Kolker A ; S ; , Allison M ; A ; , Johannesson K ; H
刊名: Global Biogeochemical Cycles
ISSN: 8866236
出版年: 2013
卷: 27, 期: 1 起始页码: 154
结束页码: 166
语种: 英语
英文关键词: carbon
; isotope
; POC
; radiocarbon
; river
Scopus关键词: Mississippi-atchafalaya rivers
; Organic components
; Particulate organic carbon
; POC
; radiocarbon
; Radiocarbon analysis
; Single components
; Thermo-chemical stability
; Carbon
; Carbon dioxide
; Isotopes
; Suspended sediments
; Rivers
; age structure
; bedload
; biogeochemistry
; carbon isotope
; carbon sink
; floodplain
; fluvial deposit
; particulate organic carbon
; pyrolysis
; radiocarbon dating
; river discharge
; river system
; sediment chemistry
; Atchafalaya River
; Atlantic Ocean
; Gulf of Mexico
; Louisiana
; Mississippi Delta
; Mississippi River
; United States
英文摘要: Applying ramped pyrolysis radiocarbon analysis to suspended river sediments, we generate radiocarbon (14C) age spectra for particulate organic carbon (POC) from the lower Mississippi-Atchafalaya River system (MARS) to better understand a major river system's role in carbon transport. Ramped pyrolysis 14C analysis generates age distributions of bulk carbon based on thermochemical stability of different organic components. Our results indicate higher proportions of older material in the POC during higher discharge. Ages increase throughout the high-discharge age spectra, indicating that no single component of the POC is responsible for the overall age increases observed. Instead, older material is contributed across the POC age spectrum and unrelated to increased bedload suspension. In this comparison of 2 spring discharges, less than half of the POC transported during higher discharge is less than 1000 14C years in age, constraining of the role of the MARS as a flux of atmospheric CO2 toward longer-term sedimentary sinks in the Mississippi delta and the Gulf of Mexico. The results suggest that delta-building processes benefit disproportionately from high discharge events carrying larger amounts of sediment because these events involve both a higher proportion of millennially-aged carbon from floodplain exchange of POC and a potentially higher proportion of petrogenic carbon (30-530% increase). Overall, an internally consistent picture of PO14C age distributions from a major river system emerges, as differences in space and time are small compared to the range of ages of POC sources in such a large basin. ©2013. 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/77600
Appears in Collections: 气候变化事实与影响
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作者单位: Department of Earth and Environmental Sciences, Tulane University, Blessey 210, New Orleans, LA 70118, United States; Louisiana Universities Marine Consortium, Chauvin, LA, United States; Institute for Geophysics, Jackson School of Geosciences, University of Texas, Austin, TX, United States
Recommended Citation:
Rosenheim B,E,, Roe K,et al. River discharge influences on particulate organic carbon age structure in the Mississippi/Atchafalaya River System[J]. Global Biogeochemical Cycles,2013-01-01,27(1)