Tidal mixing and the Meridional Overturning Circulation from the Last Glacial Maximum
Tidal mixing and the Meridional Overturning Circulation from the Last Glacial Maximum
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DOI：
10.1029/2009gl039309
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发表时间：
2009-08
影响因子：
5.2
通讯作者：
J. Green;C. Green;G. Bigg;T. Rippeth;J. Scourse;Katsuto Uehara
中科院分区：
文献类型：
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作者：
J. Green;C. Green;G. Bigg;T. Rippeth;J. Scourse;Katsuto Uehara
使用全球潮汐模型表明，末次盛冰期（LGM；距今 18,000-22,000 年）期间向深海供应的潮汐能较多。结果用于修改为当前和末次盛冰期海洋建立的海洋-大气耦合模型中的垂直混合率。末次盛冰期期间机械能水平的增加被较新鲜的北大西洋上游所抵消，尽管隐含混合能增加了三倍，但导致循环和深水形成减少。这确定了在气候模型中准确表示垂直混合对于估计快速灾难性古海洋事件的恢复时间尺度和时间的重要性。根据垂直混合方案中隐含能量的估计水平，建议对基于扩散率的混合方案进行修正。
Using a global tidal model it is shown that the supply of tidal energy to the deep ocean was larger during the Last Glacial Maximum (LGM; 18,000–22,000 years BP). The results were used to modify the rate of vertical mixing in a coupled ocean‐atmosphere model set up for the present and LGM oceans. The increased levels of mechanical energy during the LGM were countered by a fresher upper North Atlantic, which led to a reduced circulation and deep water formation in spite of a trebling of the implicit mixing energy. This identifies the significance of accurately representing vertical mixing in climate models to estimate the recovery time‐scales and timings of rapid catastrophic paleoceanographic events. From the estimated levels of implicit energy in the vertical mixing scheme an amendment to diffusivity based mixing schemes is suggested.