Last Century Warming Over the Canadian Atlantic Shelves Linked to Weak Atlantic Meridional Overturning Circulation
Last Century Warming Over the Canadian Atlantic Shelves Linked to Weak Atlantic Meridional Overturning Circulation
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DOI：
10.1029/2018gl080083
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发表时间：
2018-08
影响因子：
5.2
通讯作者：
B. Thibodeau;C. Not;Jiang Zhu;A. Schmittner;D. Noone;C. Tabor;Jiaxu Zhang;Zhengyu Liu
中科院分区：
文献类型：
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作者：
B. Thibodeau;C. Not;Jiang Zhu;A. Schmittner;D. Noone;C. Tabor;Jiaxu Zhang;Zhengyu Liu
大西洋纬向翻转环流（AMOC）是全球气候系统的重要组成部分。最近的研究表明，二十世纪的AMOC在过去的一千年中以前所未有的幅度（~15%）减弱。在这里，我们提出了一个记录的底栖有孔虫从沉积物岩心从劳伦特海峡和证明，δ 18 O的趋势与AMOC的强度。在这100年的记录中，AMOC信号稳步下降，在20世纪70年代末达到最低值，最弱的AMOC信号保持不变，直到2000年。我们还提供了一个更长的δ 18 O记录1,500年，并强调了上个世纪δ 18 O趋势的独特性。此外，小冰期的特征是统计上较重的δ 18 O，表明相对较弱的AMOC。讨论了在全球变暖和高纬度淡水输入下驱动AMOC强度的机制的意义。
The Atlantic meridional overturning circulation (AMOC) is a key component of the global climate system. Recent studies suggested a twentieth‐century weakening of the AMOC of unprecedented amplitude (~15%) over the last millennium. Here we present a record of δ18O in benthic foraminifera from sediment cores retrieved from the Laurentian Channel and demonstrate that the δ18O trend is linked to the strength of the AMOC. In this 100‐year record, the AMOC signal decreased steadily to reach its minimum value in the late 1970s, where the weakest AMOC signal then remains constant until 2000. We also present a longer δ18O record of 1,500 years and highlight the uniqueness of the last century δ18O trend. Moreover, the Little Ice Age period is characterized by statistically heavier δ18O, suggesting a relatively weak AMOC. Implications for understanding the mechanisms driving the intensity of AMOC under global warming and high‐latitude freshwater input are discussed.