Bipolar impact and phasing of Heinrich-type climate variability
Bipolar impact and phasing of Heinrich-type climate variability
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DOI：
10.1038/s41586-023-05875-2
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发表时间：
2023-04
期刊：
影响因子：
64.8
通讯作者：
Kaden Martin;C. Buizert;J. Edwards;M. Kalk;Ben Riddell-Young;E. Brook;R. Beaudette;J. Severinghaus-J.
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文献类型：
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作者：
Kaden Martin;C. Buizert;J. Edwards;M. Kalk;Ben Riddell-Young;E. Brook;R. Beaudette;J. Severinghaus-J.
在最后一个冰河时代，劳伦泰德冰盖展示了北大西洋沉积物中记录的极端冰山排放事件。这些海因里希事件具有深远的气候影响，包括对水文和地球化学循环的广泛破坏。它们发生在Heinrich stadials-寒冷时期，大西洋翻转环流强烈减弱。海因里希型变异在格陵兰岛水同位素比中并不明显，这是一个过时的现场温度代理，使评估其区域气候影响和分阶段对抗南极气候变化的努力变得复杂。在这里，我们表明，海因里希事件没有检测到的温度影响格陵兰岛和冷却发生在几个海因里希stadials的发病，这两种类型的海因里希变化有一个明显的印记南极气候。南极冰芯显示，在海因里希事件期间，与甲烷增加同步的加速变暖，表明大气遥相关，尽管没有格陵兰气候信号。格陵兰冰芯氮稳定同位素比是一个敏感的温度指标，表明海因里希体育场1（距今17800年，目前定义为1950年）开始时突然冷却约3摄氏度。南极变暖滞后于冷却133 ± 93年，与海洋遥相关一致。巧合的是，近端网站的海因里希事件比远程网站的影响较小，这表明空间复杂的事件动态。
During the last ice age, the Laurentide Ice Sheet exhibited extreme iceberg discharge events that are recorded in North Atlantic sediments. These Heinrich events have far-reaching climate impacts, including widespread disruptions to hydrological and biogeochemical cycles, –. They occurred during Heinrich stadials—cold periods with strongly weakened Atlantic overturning circulation, –. Heinrich-type variability is not distinctive in Greenland water isotope ratios, a well-dated site temperature proxy, complicating efforts to assess their regional climate impact and phasing against Antarctic climate change. Here we show that Heinrich events have no detectable temperature impact on Greenland and cooling occurs at the onset of several Heinrich stadials, and that both types of Heinrich variability have a distinct imprint on Antarctic climate. Antarctic ice cores show accelerated warming that is synchronous with increases in methane during Heinrich events, suggesting an atmospheric teleconnection, despite the absence of a Greenland climate signal. Greenland ice-core nitrogen stable isotope ratios, a sensitive temperature proxy, indicate an abrupt cooling of about three degrees Celsius at the onset of Heinrich Stadial 1 (17.8 thousand years before present, where present is defined as 1950). Antarctic warming lags this cooling by 133 ± 93 years, consistent with an oceanic teleconnection. Paradoxically, proximal sites are less affected by Heinrich events than remote sites, suggesting spatially complex event dynamics.