气候变化领域集成服务门户(CCPortal): Radiocarbon ages and plateau definitions of sediments from the abyssal ocean

CCPortal

DOI	https://doi.org/10.1594/PANGAEA.820475
	Radiocarbon ages and plateau definitions of sediments from the abyssal ocean
	Sarnthein; Michael; Schneider; Birgit; Grootes; Pieter Meiert
发布日期	2013-10-15
数据集类型	dataset
英文简介	Ice core records demonstrate a glacial-interglacial atmospheric CO2 increase by ~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 d14C dataset 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 working hypothesis that the modern regression of DIC vs d14C also applies for LGM times, which implies that a mean LGM aging by ~600 14C yr corresponded to a global rise of ~85-115 µmol DIC/kg 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 <10µmol/kg in the Atlantic sector of the Southern Ocean, possibly also in the subpolar North Pacific. The outlined 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-permil drop in atmospheric d14C during the so-called HS-1 'Mystery Interval', when atmospheric 14C production rates were largely constant.
空间范围	Median Latitude: 33.751360 * Median Longitude: 172.782385 * South-bound Latitude: -13.082500 * West-bound Longitude: 117.383333 * North-bound Latitude: 67.866660 * East-bound Longitude: -21.765000
时间范围	1994-05-05T00:00:00 - 2002-05-23T00:00:00
语种	英语
国家	国际
学科大类	气候变化
学科子类	气候变化
文献类型	数据集
条目标识符	http://gcip.llas.ac.cn/handle/2XKMVOVA/233561
推荐引用方式 GB/T 7714	Sarnthein,Michael,Schneider,et al. Radiocarbon ages and plateau definitions of sediments from the abyssal ocean.2013-10-15.https://doi.org/10.1594/PANGAEA.820475.