DOI: 10.1016/j.quascirev.2014.11.012
Scopus记录号: 2-s2.0-84918767406
论文题名: Deglacial weakening of the oceanic soft tissue pump: Global constraints from sedimentary nitrogen isotopes and oxygenation proxies
作者: Galbraith E.D. ; Jaccard S.L.
刊名: Quaternary Science Reviews
ISSN: 2773791
出版年: 2015
卷: 109 起始页码: 38
结束页码: 48
语种: 英语
英文关键词: Biological pump
; Carbon dioxide
; Dissolved oxygen
; Ice ages
; Iron fertilization
; Marine sediments
; Nitrogen isotopes
; Ocean circulation
Scopus关键词: Carbon
; Carbon dioxide
; Dissolved oxygen
; Glacial geology
; Isotopes
; Nitrogen
; Oxygenation
; Sedimentology
; Submarine geology
; Tissue
; Biological pumps
; Ice age
; Iron fertilization
; Marine sediments
; Nitrogen isotopes
; Ocean circulation
; Oceanography
; accumulation
; benthos
; biological pump
; carbon dioxide
; deglaciation
; Holocene
; Last Glacial Maximum
; marine sediment
; meridional circulation
; nitrogen isotope
; oxygenation
; polar region
; westerly
; Pacific Ocean
; Pacific Ocean (North)
英文摘要: Among the many potential explanations for the 80ppm rise of atmospheric CO2 concentrations at the end of the last ice age, most involve a weakening of the oceanic soft tissue pump. Here we use global data compilations of sedimentary nitrogen isotopes and benthic oxygenation proxies to provide a synoptic global perspective on the deglacial soft tissue pump weakening. The net change between the Last Glacial Maximum and Holocene shows a removal of respired carbon everywhere that proxy data is available, with the exception of the upper 1.5km of the North Pacific, while excess nitrate accumulated in polar oceans. These observations could be explained by intensifying iron limitation, a shoaling of organic matter remineralization, and/or a change in ocean circulation, but are inconsistent with a change in the magnitude or position of the Southern mid-latitude westerlies. The net soft tissue pump weakening was front-loaded in the early deglaciation (~17.5-~14ka), when atmospheric δ13C and δ14C were changing rapidly, and appears to have contributed little net change thereafter. Superimposed on the overall deglacial trend were pronounced transient changes that coincided with variability in the Atlantic Meridional Overturning Circulation (AMOC) and bipolar seesaw. The seesaw variability is most clearly expressed as anti-phased oxygenation changes between the upper 1.5km of the North Pacific and the deep North Atlantic, consistent with an Atlantic-Pacific ventilation seesaw, but it dominated transient variability in records throughout the world. Although the soft tissue pump seesaw made little contribution to the contrast between the glacial and interglacial states, it could have contributed to deglacial variability in atmospheric CO2 and might have catalyzed the deglaciation. © 2014 Elsevier Ltd. Citation statistics:
资源类型: 期刊论文
标识符: http://119.78.100.158/handle/2HF3EXSE/60035
Appears in Collections: 过去全球变化的重建
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作者单位: Earth and Planetary Sciences, McGill University, Montreal, QC, Canada; Institute of Geological Sciences and Oeschger Center for Climate Change Research, University of Bern, Switzerland
Recommended Citation:
Galbraith E.D.,Jaccard S.L.. Deglacial weakening of the oceanic soft tissue pump: Global constraints from sedimentary nitrogen isotopes and oxygenation proxies[J]. Quaternary Science Reviews,2015-01-01,109