DOI: 10.5194/cp-9-2595-2013
Scopus记录号: 2-s2.0-84887566265
论文题名: Peak glacial 14C ventilation ages suggest major draw-down of carbon into the abyssal ocean
作者: Sarnthein M. ; Schneider B. ; Grootes P.M.
刊名: Climate of the Past
ISSN: 18149324
出版年: 2013
卷: 9, 期: 6 起始页码: 2595
结束页码: 2614
语种: 英语
Scopus关键词: abyssal zone
; carbon isotope
; data set
; deep sea
; dissolved inorganic carbon
; glacial-interglacial cycle
; Heinrich event
; ice core
; Last Glacial
; paleoclimate
; ventilation
; Pacific Ocean
; Pacific Ocean (North)
; Southern Ocean
英文摘要: Ice core records demonstrate a glacial-interglacial atmospheric CO 2 increase of ~ 100 ppm, while 14C calibration efforts document a strong decrease in atmospheric 14C concentration during this period. A calculated transfer of ~ 530 Gt of 14C-depleted carbon is required to produce the deglacial coeval rise of carbon in the atmosphere and terrestrial biosphere. This amount is usually ascribed to oceanic carbon release, although the actual mechanisms remained elusive, since an adequately old and carbon-enriched deep-ocean reservoir seemed unlikely. Here we present a new, though still fragmentary, ocean-wide Δ14C data set showing that during the Last Glacial Maximum (LGM) and Heinrich Stadial 1 (HS-1) the maximum 14C age difference between ocean deep waters and the atmosphere exceeded the modern values by up to 1500 14C yr, in the extreme reaching 5100 14C yr. Below 2000 m depth the 14C ventilation age of modern ocean waters is directly linked to the concentration of dissolved inorganic carbon (DIC). We propose as a working hypothesis that the modern regression of DIC vs. Δ14C also applies for LGM times, which implies that a mean LGM aging of ~ 600 14C yr corresponded to a global rise of ~ 85-115 μmol DIC kg-1 in the deep ocean. Thus, the prolonged residence time of ocean deep waters may indeed have made it possible to absorb an additional ~ 730-980 Gt DIC, one third of which possibly originated from intermediate waters. We also infer that LGM deep-water O2 dropped to suboxic values of < 10 μmol kg-1 in the Atlantic sector of the Southern Ocean, possibly also in the subpolar North Pacific. The deglacial transfer of the extra-aged, deep-ocean carbon to the atmosphere via the dynamic ocean-atmosphere carbon exchange would be sufficient to account for two trends observed, (1) for the increase in atmospheric CO2 and (2) for the 190‰ drop in atmospheric Δ14C during the so-called HS-1 "Mystery Interval", when atmospheric 14C production rates were largely constant. © Author(s) 2013. 资助项目: DFG, Deutsche Forschungsgemeinschaft
; DFG, Deutsche Forschungsgemeinschaft
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资源类型: 期刊论文
标识符: http://119.78.100.158/handle/2HF3EXSE/49342
Appears in Collections: 气候变化与战略
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Recommended Citation:
Sarnthein M.,Schneider B.,Grootes P.M.. Peak glacial 14C ventilation ages suggest major draw-down of carbon into the abyssal ocean[J]. Climate of the Past,2013-01-01,9(6)