Gradual South‐North Climate Transition in the Atlantic Realm Within the Younger Dryas
Gradual South‐North Climate Transition in the Atlantic Realm Within the Younger Dryas
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DOI：
10.1029/2021gl092620
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发表时间：
2021-03
影响因子：
5.2
通讯作者：
Haiwei Zhang;Hai Cheng;C. Spötl;Xu Zhang;F. Cruz;A. Sinha;A. Auler;N. Stríkis;Xianfeng Wang-Xianfe
中科院分区：
文献类型：
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作者：
Haiwei Zhang;Hai Cheng;C. Spötl;Xu Zhang;F. Cruz;A. Sinha;A. Auler;N. Stríkis;Xianfeng Wang-Xianfe
新仙女木（Younger Dryas，简称YD）是一个气候突变事件，人们对它的研究非常广泛，但对其结构的了解仍然很少。巴西东北部的气候对与大西洋气候突变相关的热带辐合带（ITCZ）的纬度位置非常敏感。在这里，我们使用精确的speleothem多代理记录从巴西东北部的YD内的ITCZ位置的变化报告。我们提供的证据表明，ITCZ逐渐向北迁移的西风带和极锋在北方高纬度地区内的YD的向极移动之前。这可能是由于大西洋经向翻转环流（AMOC）减弱导致大气中CO2浓度逐渐增加。我们认为，大气中CO2的持续增加可能引发了AMOC的恢复和大西洋大气环流的重组。
The abrupt climate event Younger Dryas (YD) has been extensively studied; however, its structure is still poorly understood. Climate in northeastern Brazil is very sensitive to the latitudinal position of the intertropical convergence zone (ITCZ) associated with abrupt climate change in the Atlantic. Here, we report changes in the ITCZ position within the YD by using precise speleothem multiproxy records from northeastern Brazil. We provide evidence for a gradual northward migration of the ITCZ preceding poleward shifts of the westerlies and the polar front in northern high latitudes within the YD. This can be attributed to gradual increase in atmospheric CO2 concentration as a consequence of the weakening Atlantic Meridional Overturning Circulation (AMOC). We suggest that a persistent increase in atmospheric CO2 might have triggered a resumption of the AMOC and reorganization of the atmosphere circulation in the Atlantic during the mid‐YD.