North Atlantic versus Southern Ocean contributions to a deglacial surge in deep ocean ventilation
North Atlantic versus Southern Ocean contributions to a deglacial surge in deep ocean ventilation
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DOI：
10.1130/g34133.1
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发表时间：
2013-06
期刊：
影响因子：
5.8
通讯作者：
L. Skinner;A. Scrivner;D. Vance;S. Barker;S. Fallon;C. Waelbroeck
中科院分区：
文献类型：
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作者：
L. Skinner;A. Scrivner;D. Vance;S. Barker;S. Fallon;C. Waelbroeck
过去的冰川-间冰期气候转变伴随着大气中二氧化碳的千年尺度脉冲，人们普遍认为这是由南大洋释放的二氧化碳造成的。然而，南大洋在调节过去的海洋-大气CO2交换中的作用的直接替代证据是稀缺的。在这里，我们使用结合放射性碳和钕同位素测量，从最后一次冰消期，以确认大大增强翻转和/或海气交换率相对于今天，特别是在博林Allerod温暖的间隔。我们表明，这种冰消期的脉冲在海洋通风不是由北大西洋翻转单独驱动的，必须涉及增加南方来源的深层沃茨的通风。因此，我们的研究结果证实，在冰川消退期间，在南大洋有效的海气（CO2）交换的物理和/或动力障碍的消除，并强调南极地区作为全球气候/碳循环反馈的关键所在地。
Past glacial-interglacial climate transitions were accompanied by millennial-scale pulses in atmospheric CO2 that are widely thought to have resulted from the release of CO2 via the Southern Ocean. However, direct proxy evidence for a Southern Ocean role in regulating past ocean-atmosphere CO2 exchange is scarce. Here we use combined radiocarbon and neodymium isotope measurements from the last deglaciation to confirm greatly enhanced overturning and/or air-sea exchange rates relative to today, in particular during the Bolling-Allerod warm interval. We show that this deglacial pulse in ocean ventilation was not driven by the North Atlantic overturning alone, and must have involved an increase in the ventilation of southern-sourced deep waters. Our results thus confirm the removal of a physical and/or dynamical barrier to effective air-sea (CO2) exchange in the Southern Ocean during deglaciation, and highlight the Antarctic region as a key locus for global climate/carbon-cycle feedbacks.