DOI: 10.1016/j.quascirev.2018.04.002
Scopus记录号: 2-s2.0-85045458594
论文题名: Mid-depth respired carbon storage and oxygenation of the eastern equatorial Pacific over the last 25,000 years
作者: Umling N.E. ; Thunell R.C.
刊名: Quaternary Science Reviews
ISSN: 2773791
出版年: 2018
卷: 189 起始页码: 43
结束页码: 56
语种: 英语
英文关键词: B/Ca
; Equatorial Pacific
; Foraminifera
; Holocene
; Micropaleontology
; Paleoceanography
; Pleistocene
; Quaternary
; Stable isotopes
; U/Ca
Scopus关键词: Calcium
; Carbon dioxide
; Carbonation
; Forestry
; Glacial geology
; Isotopes
; Oxygenation
; Productivity
; Water levels
; Equatorial Pacific
; Foraminifera
; Holocenes
; Micropaleontology
; Paleoceanography
; Pleistocene
; Quaternary
; Stable isotopes
; Organic carbon
; carbon dioxide
; carbon isotope
; carbon sequestration
; concentration (composition)
; deglaciation
; dissolution
; dissolved inorganic carbon
; Holocene
; Last Glacial Maximum
; micropaleontology
; oxygenation
; paleoceanography
; Pleistocene
; Quaternary
; speciation (biology)
; stable isotope
; Pacific Ocean
; Pacific Ocean (Equatorial)
; Cibicidoides wuellerstorfi
; Foraminifera
英文摘要: A growing body of evidence suggests that respired carbon was stored in mid-depth waters (∼1–3 km) during the last glacial maximum (LGM) and released to the atmosphere from upwelling regions during deglaciation. Decreased ventilation, enhanced productivity, and enhanced carbonate dissolution are among the mechanisms that have been cited as possible drivers of glacial CO2 drawdown. However, the relative importance of each of these mechanisms is poorly understood. New approaches to quantitatively constrain bottom water carbonate chemistry and oxygenation provide methods for estimating historic changes in respired carbon storage. While increased CO2 drawdown during the LGM should have resulted in decreased oxygenation and a shift in dissolved inorganic carbon (DIC) speciation towards lower carbonate ion concentrations, this is complicated by the interplay of carbonate compensation, export productivity, and circulation. To disentangle these processes, we use a multiproxy approach that includes boron to calcium (B/Ca) ratios of the benthic foraminifera Cibicidoides wuellerstorfi to reconstruct deep-water carbonate ion concentrations ([CO3 2−]) and the uranium to calcium (U/Ca) ratio of foraminiferal coatings in combination with benthic foraminiferal carbon isotopes to reconstruct changes in bottom water oxygen concentrations ([O2]) and organic carbon export. Our records indicate that LGM [CO3 2−] and [O2] was reduced at mid water depths of the eastern equatorial Pacific (EEP), consistent with increased respired carbon storage. Furthermore, our results suggest enhanced mixing of lower Circumpolar Deep Water (LCDW) to EEP mid water depths and provide evidence for the importance of circulation for oceanic-atmospheric CO2 exchange. © 2018 Elsevier Ltd Citation statistics:
资源类型: 期刊论文
标识符: http://119.78.100.158/handle/2HF3EXSE/112202
Appears in Collections: 气候减缓与适应
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作者单位: School of Earth, Ocean and Environment, University of South Carolina, 701 Sumter Street, EWS 617, Columbia, SC 29208, United States; Woods Hole Oceanographic Institution, Woods Hole, MA 02543, United States
Recommended Citation:
Umling N.E.,Thunell R.C.. Mid-depth respired carbon storage and oxygenation of the eastern equatorial Pacific over the last 25,000 years[J]. Quaternary Science Reviews,2018-01-01,189