DOI: 10.1038/ngeo1782
论文题名: Millennial-scale changes in atmospheric CO2 levels linked to the Southern Ocean carbon isotope gradient and dust flux
作者: Ziegler M. ; Diz P. ; Hall I.R. ; Zahn R.
刊名: Nature Geoscience
ISSN: 17520894
出版年: 2013
卷: 6, 期: 6 起始页码: 457
结束页码: 461
语种: 英语
Scopus关键词: biological pump
; carbon dioxide
; carbon isotope
; deep water
; dust
; ice core
; intermediate water
; subantarctic region
; upwelling
; Atlantic Ocean
; Southern Ocean
; Foraminifera
英文摘要: The rise in atmospheric CO2 concentrations observed at the end of glacial periods has, at least in part, been attributed to the upwelling of carbon-rich deep water in the Southern Ocean. The magnitude of outgassing of dissolved CO2, however, is influenced by the biological fixation of upwelled inorganic carbon and its transfer back to the deep sea as organic carbon. The efficiency of this biological pump is controlled by the extent of nutrient utilization, which can be stimulated by the delivery of iron by atmospheric dust particles. Changes in nutrient utilization should be reflected in the δ13C gradient between intermediate and deep waters. Here we use the δ13C values of intermediate- and bottom-dwelling foraminifera to reconstruct the carbon isotope gradient between thermocline and abyssal water in the subantarctic zone of the South Atlantic Ocean over the past 360,000 years. We find millennial-scale oscillations of the carbon isotope gradient that correspond to changes in dust flux and atmospheric CO2 concentrations as reported from Antarctic ice cores. We interpret this correlation as a relationship between the efficiency of the biological pump and fertilization by dust-borne iron. As the correlation is exponential, we suggest that the sensitivity of the biological pump to dust-borne iron fertilization may be increased when the background dust flux is low. © 2013 Macmillan Publishers Limited. All rights reserved. Citation statistics:
资源类型: 期刊论文
标识符: http://119.78.100.158/handle/2HF3EXSE/106786
Appears in Collections: 气候减缓与适应 科学计划与规划
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作者单位: School of Earth and Ocean Sciences, Cardiff University, Cardiff, CF10 3AT, United Kingdom; Institució Catalana de Recerca i Estudis Avançats (ICREA), 08010 Barcelona, Spain; Institut de Ciència i Tecnologia Ambientals (ICTA), Departament de fi'Sica, Universitat Autònoma de Barcelona, 08193 Bellaterra, Spain; Department of Xeociencias Mariñas e Ordenación Do Territorio, Facultade de Ciencias Do Mar, University of Vigo, 36310 Vigo, Spain
Recommended Citation:
Ziegler M.,Diz P.,Hall I.R.,et al. Millennial-scale changes in atmospheric CO2 levels linked to the Southern Ocean carbon isotope gradient and dust flux[J]. Nature Geoscience,2013-01-01,6(6)