Coherent deglacial changes in western Atlantic Ocean circulation.
Coherent deglacial changes in western Atlantic Ocean circulation.
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DOI：
10.1038/s41467-018-05312-3
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发表时间：
2018-07-27
影响因子：
16.6
通讯作者：
Chen T
中科院分区：
文献类型：
--
作者：
Ng HC;Robinson LF;McManus JF;Mohamed KJ;Jacobel AW;Ivanovic RF;Gregoire LJ;Chen T
过去气候的突然变化被归因于大西洋经向翻转环流（AMOC）强度的变化。然而，过去AMOC变化的确切时间和幅度仍然难以捉摸，这继续限制了我们对这种气候变率驱动机制的理解。在这里，我们显示了一个一致的信号231 Pa/230 Th代理，揭示了一个空间连贯的画面西大西洋环流变化在最后一次冰消期，在突然的千年尺度的气候转变。在冰消期开始时，我们观察到从大约1.9万年到1.65万年前（ka），西大西洋环流的早期减缓，与欧亚冰加速融化的时间一致。随后减弱的AMOC状态持续了1000多年（约16.5-15 ka），在此期间有大量的冰从劳伦泰德冰盖漂流。这一时间点表明，融化的冰在推动两步AMOC减速中发挥了作用，在海因里希体育场1期间，正反馈维持了持续的冰山崩解和气候变化。大西洋环流过去变化的确切时间和幅度及其与气候突变的关系仍然难以捉摸。在这里，作者展示了一幅西大西洋环流变化的空间连贯图，揭示了冰消期开始时AMOC的两步减速。
Abrupt climate changes in the past have been attributed to variations in Atlantic Meridional Overturning Circulation (AMOC) strength. However, the exact timing and magnitude of past AMOC shifts remain elusive, which continues to limit our understanding of the driving mechanisms of such climate variability. Here we show a consistent signal of the 231Pa/230Th proxy that reveals a spatially coherent picture of western Atlantic circulation changes over the last deglaciation, during abrupt millennial-scale climate transitions. At the onset of deglaciation, we observe an early slowdown of circulation in the western Atlantic from around 19 to 16.5 thousand years ago (ka), consistent with the timing of accelerated Eurasian ice melting. The subsequent weakened AMOC state persists for over a millennium (~16.5–15 ka), during which time there is substantial ice rafting from the Laurentide ice sheet. This timing indicates a role for melting ice in driving a two-step AMOC slowdown, with a positive feedback sustaining continued iceberg calving and climate change during Heinrich Stadial 1. The exact timing and magnitude of past changes in Atlantic Ocean circulation, and its relation to abrupt climate changes remains elusive. Here, the authors show a spatially coherent picture of western Atlantic circulation changes, which reveals a two-step AMOC slowdown at the beginning of the deglacial period.
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影响因子：
5.3
作者：
Gherardi, JM;Labeyrie, L;Cortijo, E
通讯作者：
Cortijo, E
影响因子：
--
作者：
Grousset, FE;Cortijo, E;Weber, O
通讯作者：
Weber, O
影响因子：
64.8
作者：
BROECKER, WS
通讯作者：
BROECKER, WS
DOI：
10.1016/j.nimb.2009.10.123
发表时间：
2010-04-01
影响因子：
1.3
作者：
Christl, Marcus;Lippold, Joerg;Synal, Hans-Arno
通讯作者：
Synal, Hans-Arno
影响因子：
5.2
作者：
Gregoire, Lauren J.;Otto-Bliesner, Bette;Valdes, Paul J.;Ivanovic, Ruza
通讯作者：
Ivanovic, Ruza