日本东京大学Sproson, Adam D.团队在研究近同步的北半球和巴塔哥尼亚冰原在末次冰期的变化中取得新进展。2024年5月8日，国际知名学术期刊《自然—地球科学》发表了这一成果。

据了解，北半球的日照强度与南半球的气候代用物大致相同，从而得出一个共同的结论，即，在晚第四纪期间，北半球的日照影响了南半球的气候。然而，南半球中纬度地区的记录表明，巴塔哥尼亚和新西兰冰川的推进早于末次盛冰期(29,000-18,000年前)。为了解决几乎同步的全球气候变化问题，需要对末次冰期的中纬度冰川活动进行持续的记录。

研究团队从智利边缘提取沉积铍的同位素记录，以追踪当地冰川的接近程度。研究评估了过去约89,000年巴塔哥尼亚冰盖海洋边缘的位置。研究发现，冰期和消冰期与北半球冰盖同步或早于北半球冰盖数千年。冰川扩张是由赤道迁移和南方西风的加强所驱动的，这与全球变冷和更陡峭的经向温度梯度有关。

当全球变暖与倾角增加和北半球急剧变冷同时发生时，冰川就会终止。研究结果表明，在轨道时间尺度上，平均全球气候、倾角和半球间远距联系之间的复杂相互作用，可能导致通过南部西风带的位移而接近同步全球冰盖演变。

附：英文原文

Title: Near-synchronous Northern Hemisphere and Patagonian Ice Sheet variation over the last glacial cycle

Author: Sproson, Adam D., Yokoyama, Yusuke, Miyairi, Yosuke, Aze, Takahiro, Clementi, Vincent J., Riechelson, Hailey, Bova, Samantha C., Rosenthal, Yair, Childress, Laurel B.

Issue&Volume: 2024-05-08

Abstract: Northern Hemisphere insolation intensity is roughly in phase with Southern Hemisphere climate proxies, leading to a common conclusion that northern insolation forces southern climate during the Late Quaternary. However, mid-latitude Southern Hemisphere records place the advance of Patagonian and New Zealand glaciers before the Last Glacial Maximum (29,000–18,000years ago) by several millennia. To resolve the cause(s) of nearly synchronous global climate change requires continuous archives of mid-latitude glacial activity for the last glacial cycle. Here we assess the position of the Patagonian Ice Sheet’s marine-terminating margin over the last ~89,000years using a sedimentary-beryllium-isotope record from the Chilean margin to track the proximity of local glaciers. We find that glaciations and deglaciations are synchronous with or precede Northern Hemisphere ice sheets by thousands of years. Glacial expansion was driven by equatorward migration and strengthening of the southern westerly winds, linked to global cooling and a steeper meridional temperature gradient. Glacial terminations occurred when global warming coincided with increasing obliquity and dramatic Northern Hemisphere cooling. Our results suggest that, on orbital timescales, a complex interaction between mean global climate, obliquity and interhemispheric teleconnections could have led to near-synchronous global ice sheet evolution through displacements of the southern westerlies.

DOI: 10.1038/s41561-024-01436-y

Source: https://www.nature.com/articles/s41561-024-01436-y