Role of the Tropical Atlantic for the Interhemispheric Heat Transport During the Last Deglaciation
Role of the Tropical Atlantic for the Interhemispheric Heat Transport During the Last Deglaciation
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DOI：
10.1029/2020pa004107
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发表时间：
2021-05-01
影响因子：
3.5
通讯作者：
Friedrich, Oliver
中科院分区：
文献类型：
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作者：
Meier, Karl J. F.;Bahr, Andre;Friedrich, Oliver
在最后一次冰消期，大西洋经向翻转环流的千年尺度扰动突然发生，极大地改变了半球间的热量分布，影响了大陆冰量和水文气候等。相关的越赤道热输送是否以及如何受到向南流动的巴西流（BC）和向北流动的北巴西流（NBC）之间的相互作用的控制仍然存在争议。为了评估末次冰消期热带热输送的作用，我们获得了BC域21.5 ° S处的高分辨率有孔虫Mg/Ca基海表温度（SST）记录。这些数据显示，在海因里希体育场1期间，公元前至少有4.6摄氏度的未记录变暖，大约16 ka，表明热带南大西洋有大量的海洋热量积累。与此同时，NBC的强烈减弱阻止了这些多余的热量释放到北方热带地区。观测到的热量积累幅度大大超过了数值模型模拟，强调需要进一步仔细研究极端气候事件期间的大气和海洋热量传输。
During the last deglaciation abrupt millennial-scale perturbations of the Atlantic Meridional Overturning Circulation massively altered the interhemispheric heat distribution affecting, for example, continental ice volume and hydroclimate. If and how the related cross-equatorial heat transport was controlled by the interplay between the southward-flowing Brazil Current (BC) and northward-flowing North Brazil Current (NBC) remains controversial. To assess the role of tropical heat transport during the last deglaciation, we obtained a high-resolution foraminiferal Mg/Ca-based sea surface temperature (SST) record from the BC domain at 21.5 degrees S. The data reveal a yet undocumented warming of at least 4.6 degrees C of the BC during Heinrich Stadial 1 at similar to 16 ka indicating massive oceanic heat accumulation in the tropical South Atlantic. Simultaneously, a strongly diminished NBC prevented the release of this excess heat into the northern tropics. The observed magnitude of heat accumulation substantially exceeds numerical model simulations, stressing the need to further scrutinize atmospheric and oceanic heat transport during extreme climatic events.