Distinct roles of the Southern Ocean and North Atlantic in the deglacial atmospheric radiocarbon decline
Distinct roles of the Southern Ocean and North Atlantic in the deglacial atmospheric radiocarbon decline
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DOI：
10.1016/j.epsl.2014.03.020
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发表时间：
2014-05-15
影响因子：
5.3
通讯作者：
Haug, Gerald H.
中科院分区：
文献类型：
--
作者：
Hain, Mathis P.;Sigman, Daniel M.;Haug, Gerald H.
在大气CO2 C-14/C（Delta C-14（atm））变化的背景下，自上一次冰期以来，两次Delta C-14（atm）急剧下降与深层封存的低C-14 CO2通过南大洋表面的排放或北大西洋深水（NADW）形成的突然开始有关。在模型模拟使用改进的重建C-14生产，大西洋环流的变化和南大洋CO2的释放都有助于整体冰消期三角洲C-14（大气压）的下降，但只有NADW的开始可以重现急剧三角洲C-14（大气压）的下降。为了完全模拟Delta C-l4（atm）数据，需要在NADW开始之前立即进行额外的处理。我们假设，这些“早期”三角洲C-14（大气压）下降记录增厚海洋的温跃层响应重建的NADW和/或在南半球西风的变化瞬态关闭。这种温跃层增厚可能在触发NADW爆发中发挥了作用。(C)2014爱思唯尔有限公司版权所有。
In the context of the atmospheric CO2 C-14/C (Delta C-14(atm)) changes since the last ice age, two episodes of sharp Delta C-14(atm) decline have been related to either the venting of deeply sequestered low-C-14 CO2 through the Southern Ocean surface or the abrupt onset of North Atlantic Deep Water (NADW) formation. In model simulations using an improved reconstruction of C-14 production, Atlantic circulation change and Southern Ocean CO2 release both contribute to the overall deglacial Delta C-14(atm) decline, but only the onset of NADW can reproduce the sharp Delta C-14(atm) declines. To fully simulate Delta C-l4(atm) data requires an additional process that immediately precedes the onsets of NADW. We hypothesize that these "early" Delta C-14(atm) declines record the thickening of the ocean's thermocline in response to reconstructed transient shutdown of NADW and/or changes in the southern hemisphere westerly winds. Such thermocline thickening may have played a role in triggering the NADW onsets. (C) 2014 Elsevier B.V. All rights reserved.