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Deglacial Atlantic Ocean Ventilation Rates

大西洋冰消期通风率

基本信息

批准号：
NE/F016751/1
负责人：
Tina Van De Flierdt
金额：
$ 28.29万
依托单位：
Imperial College London
依托单位国家：
英国
项目类别：
Research Grant
财政年份：
2009
资助国家：
英国
起止时间：
2009 至无数据
项目状态：
已结题

来源：
https://gtr.ukri.org/projects?ref=NE%2FF016751%2F1
关键词：
Deglacial Atlantic Ocean Ventilation Rates

项目摘要

This research project addresses a scientific issue that is of first-order importance, deglacial ocean ventilation rates. Ocean ventilation rates describe the time elapsed since a water mass last 'saw' the atmosphere. This age information is important because ocean ventilation rates are intimately linked to climate change through the formation of deep waters at high latitudes. Most of the carbon in the coupled ocean-atmosphere system is located in the deep ocean, which exerts an important influence on climate via the greenhouse gas connection. Small changes in the rate of deep water formation are likely to have a large impact on the atmospheric carbon budget. Geochemical analyses of marine sediments cores show that many such changes in ocean circulation have happened in the geological past. The most recent large amplitude changes occurred during the last deglaciation (~20 to 10 thousand years ago), a time when the large ice sheets in North America and Northern Europe were retreating. Measurements of the radiocarbon content of deep-sea corals indicate that during the last deglaciation, the ocean was flipping back and forth between different modes of operation (i.e., different water mass distributions and different flow rates). However, it is impossible to convert the radiocarbon contents of water mass masses directly into ventilation rates, if we do not know the mixing proportions of water masses derived from high northern and southern latitude sources. This hurdle can be overcome by measuring the neodymium (Nd) isotopic composition in deep-sea corals from the western North Atlantic Ocean. Deep-sea corals are reliable recorders of the Nd isotopic composition of the water mass in which they grow. The Nd isotopic composition of the water mass in turn, is closely tied to the age of the continents in its formation area, leading to very different Nd isotopic signatures for high northern versus southern latitude waters in the Atlantic Ocean. These distinct signatures enable us to 'un-mix' the composition of waters in the western North Atlantic during abrupt climate events of the last deglaciation. Applying this knowledge of water mass mixtures to the existing radiocarbon data set on the same, absolutely dated samples, we can unravel how rapid and from where ventilation of the Atlantic Ocean occurred during the last deglaciation. Information such as this has not been obtained before, and has the potential to revolutionise our understanding of the ocean's role in rapid climate change.

这一研究项目解决了一个首要的科学问题，即去冰川海洋通风率。海洋通风率描述了自水团最后一次看到大气以来所经过的时间。这一年龄信息很重要，因为海洋通风率与高纬度深水的形成与气候变化密切相关。海洋-大气耦合系统中的大部分碳位于深海，通过与温室气体的联系对气候产生重要影响。深水形成速度的微小变化可能会对大气碳收支产生重大影响。海洋沉积物岩心的地球化学分析表明，在地质过去曾发生过许多这样的海洋环流变化。最近的大规模变化发生在最后一次冰川消融(约2万至1万年前)，当时北美和北欧的大冰盖正在消退。对深海珊瑚放射性碳含量的测量表明，在上一次冰川消融期间，海洋在不同的作业模式(即不同的水团分布和不同的流速)之间来回翻转。然而，如果我们不知道南北高纬度来源的水团的混合比例，就不可能将水团的放射性碳含量直接转换为通风率。这一障碍可以通过测量来自北大西洋西部的深海珊瑚中的钕(ND)同位素组成来克服。深海珊瑚是它们生长的水团中ND同位素组成的可靠记录器。反过来，水团的Nd同位素组成又与其形成区域内大陆的年龄密切相关，导致大西洋高纬度水域南北两个纬度水域的ND同位素特征截然不同。这些不同的信号使我们能够在最后一次冰川消融的突然气候事件期间‘混合’北大西洋西部水域的组成。将这种水团混合物的知识应用于同一绝对年代样品的现有放射性碳数据集，我们可以解开上次冰川消融期间大西洋通风发生的速度和地点。这样的信息以前从未获得过，有可能彻底改变我们对海洋在快速气候变化中所扮演角色的理解。

项目成果

期刊论文数量（10）

专著数量（0）

科研奖励数量（0）

会议论文数量（0）

专利数量（0）

Neodymium isotopic composition and concentration in the western North Atlantic Ocean: Results from the GEOTRACES GA02 section

DOI：
10.1016/j.gca.2015.12.019
发表时间：
2016-03
期刊：
Geochimica et Cosmochimica Acta
影响因子：
5
作者：
M. Lambelet;T. Flierdt;K. Crocket;M. Rehkämper;K. Kreissig;B. Coles;M. Rijkenberg;L. Gerringa
通讯作者：
M. Lambelet;T. Flierdt;K. Crocket;M. Rehkämper;K. Kreissig;B. Coles;M. Rijkenberg;L. Gerringa

GEOTRACES intercalibration of neodymium isotopes and rare earth element concentrations in seawater and suspended particles. Part 2: Systematic tests and baseline profiles

DOI：
10.4319/lom.2012.10.252
发表时间：
2012-04
期刊：
Limnology and Oceanography: Methods
影响因子：
0
作者：
K. Pahnke;T. van de Flierdt;K. Jones;M. Lambelet;S. Hemming;S. Goldstein
通讯作者：
K. Pahnke;T. van de Flierdt;K. Jones;M. Lambelet;S. Hemming;S. Goldstein

Measurement of fossil deep-sea coral Nd isotopic compositions and concentrations by TIMS as NdO+, with evaluation of cleaning protocols

DOI：
10.1016/j.chemgeo.2014.03.011
发表时间：
2014-05-26
期刊：
CHEMICAL GEOLOGY
影响因子：
3.9
作者：
Crocket, Kirsty C.;Lambelet, Myriam;Robinson, Laura F.
通讯作者：
Robinson, Laura F.

Evidence of silicic acid leakage to the tropical Atlantic via Antarctic Intermediate Water during Marine Isotope Stage 4

海洋同位素第四阶段期间硅酸通过南极中层水泄漏到热带大西洋的证据

DOI：
10.1002/palo.20030
发表时间：
2013
期刊：
Paleoceanography
影响因子：
0
作者：
Griffiths J
通讯作者：
Griffiths J

Global ocean conveyor lowers extinction risk in the deep sea

全球海洋输送机降低深海灭绝风险

DOI：
10.1016/j.dsr.2014.03.004
发表时间：
2014
期刊：
影响因子：
0
作者：
Henry LA;Frank N;Hebbeln D;Wienberg C;Robinson L;van de Flierdt T;Dahl M;Douarin M;Morrison CL;Correa ML;Rogers AD;Ruckelshausen M;Roberts JM
通讯作者：
Roberts JM