美国俄勒冈州立大学Martin, Kaden C小组近日研究海因里希型气候变率的两极影响和相位取得新突破。2023年4月24日出版的《自然》发表了这项成果。

研究人员表明，海因里希事件没有检测到温度对格陵兰岛的影响，并且冷却发生在几个海因里希亚冰期的开始阶段，这两种类型的海因里希变率对南极气候变化有明显的影响。南极冰芯证据显示，加速变暖与海因里希事件期间甲烷的增加同步，尽管格陵兰岛的气候信号没有出现，也表明了大气的遥相关性。格陵兰冰芯氮稳定同位素比率是一个敏感温度代用指标，表明在海因里希亚冰期1 (在出现之前距今1.78万年，其中出现被定义为1950年)突然降温约3摄氏度。

南极变暖比这种冷却滞后133± 93 年，这与海洋遥相关一致。矛盾的是，邻近的地点受海因里希事件的影响比远处的地点要小，这表明了事件动力学在空间上的复杂性。

据了解，在上一个冰河时期，劳伦提的冰盖展示了北大西洋沉积物中记录的极端冰山排放事件。这些海因里希事件引发了深远的气候影响，包括对水文和生物地球化学循环的广泛破坏。它们发生在海因里希亚冰期阶段——大西洋翻转环流强烈减弱的寒冷时期。海因里希型变率，在格陵兰岛水同位素比率中表现并不明显，这是一个过时的现场温度代用指标，使得评估其区域气候影响和应对南极气候变化的努力复杂化。

附：英文原文

Title: Bipolar impact and phasing of Heinrich-type climate variability

Author: Martin, Kaden C., Buizert, Christo, Edwards, Jon S., Kalk, Michael L., Riddell-Young, Ben, Brook, Edward J., Beaudette, Ross, Severinghaus, Jeffrey P., Sowers, Todd A.

Issue&Volume: 2023-04-24

Abstract: 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 (17.8thousand years before present, where present is defined as 1950). Antarctic warming lags this cooling by 133±93years, consistent with an oceanic teleconnection. Paradoxically, proximal sites are less affected by Heinrich events than remote sites, suggesting spatially complex event dynamics.

DOI: 10.1038/s41586-023-05875-2

Source: https://www.nature.com/articles/s41586-023-05875-2