Mechanisms for millennial‐scale global synchronization during the last glacial period
Mechanisms for millennial‐scale global synchronization during the last glacial period
复制标题
末次冰期千年尺度的全球同步机制
DOI：
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发表时间：
2005
期刊：
影响因子：
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通讯作者：
T. Ivanochko
中科院分区：
文献类型：
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作者：
A. Timmermann;U. Krebs;Flavio Justino;H. Goosse;T. Ivanochko
上一次冰川时期的全球气候被突然变暖和偶尔涌入北大西洋的淡水脉冲打断，扰乱了深水生产。这些巨大的淡水脉冲被称为海因里希事件，部分原因是劳伦蒂冰盖内的不稳定。来自北大西洋的古证据表明，这些事件改变了深水的产生，并改变了整个北半球的下游气候。在热带西太平洋，表面温度和盐度随着高纬度的海洋和气候变化而变化。在这里，我们介绍了耦合模拟实验的结果，这些实验揭示了北大西洋和西热带太平洋之间可能的动力联系。这种联系涉及北大西洋千年尺度冰川密度变化带来的全球海洋驻波模式、经向海面温度梯度引发的大气遥相关以及局地海气相互作用。此外，我们的模拟结果与Cariaco盆地、印度洋、苏鲁海和澳大利亚北部的水文记录进行了比较。
Global climate during the last glacial period was punctuated by abrupt warmings and occasional pulses of freshwater into the North Atlantic that disrupted deepwater production. These massive freshwater pulses known as Heinrich events arose, in part, from instabilities within the Laurentide ice sheet. Paleoevidence from the North Atlantic suggests that these events altered the production of deep water and changed downstream climate throughout the Northern Hemisphere. In the tropical western Pacific sea, surface temperatures and salinity varied together with ocean and climate changes at high latitudes. Here we present results from coupled modeling experiments that shed light on a possible dynamical link between the North Atlantic Ocean and the western tropical Pacific. This link involves a global oceanic standing wave pattern brought about by millennial-scale glacial density variations in the North Atlantic, atmospheric teleconnections triggered by meridional sea surface temperature gradients, and local air-sea interactions. Furthermore, our modeling results are compared with hydrological records from the Cariaco basin, the Indian Ocean, the Sulu Sea, and northern Australia.