Josey Simon A, Meijers Andrew J S, Blaker Adam T, Grist Jeremy P, Mecking Jenny, Ayres Holly C
National Oceanography Centre, Southampton, UK.
British Antarctic Survey, Cambridge, UK.
Nature. 2024 Dec;636(8043):635-639. doi: 10.1038/s41586-024-08368-y. Epub 2024 Dec 18.
Recent Antarctic sea-ice decline is a substantial source of concern, notably the record low in 2023 (ref. ). Progress has been made towards establishing the causes of ice loss but uncertainty remains about its consequences for ocean-atmosphere interaction. Resolution of this uncertainty is important as ice decline can substantially alter surface heat loss and thus the ocean and atmosphere. Here we show that the strongest winter 2023 ice-retraction regions provide an important new source of turbulent ocean heat loss to the atmosphere in wintertime. Ice concentration in these regions (located primarily in the Weddell, Bellingshausen and Ross seas) is reduced by up to 80% and is accompanied by an unprecedented doubling of mid-winter ocean heat loss. Also, there is a phase shift in the time of peak heat loss from late April to mid-June, with weaker than normal heat loss in austral autumn. The winter surface-heat-loss intensification is accompanied by substantial changes on both sides of the ocean-atmosphere interface. These include increases in atmospheric-storm frequency and surface-heat-loss-driven dense water formation, although the implications of the densification for broader processes such as Antarctic bottom water formation remain unclear. Our results reveal that the 2023 Antarctic sea-ice loss has substantially modified air-sea interaction in the Southern Ocean and motivate in-depth analysis of the wider climate-system impacts.
近期南极海冰减少引发了广泛关注，尤其是2023年创下历史新低（参考文献）。在确定海冰损失原因方面已取得进展，但对于其对海气相互作用的影响仍存在不确定性。解决这一不确定性很重要，因为海冰减少会显著改变地表热量损失，进而影响海洋和大气。我们发现，2023年冬季海冰退缩最强烈的区域成为冬季海洋向大气湍流热损失的一个重要新来源。这些区域（主要位于威德尔海、别林斯高晋海和罗斯海）的海冰浓度降低了80%，同时冬季海洋热损失增加了一倍，这是前所未有的。此外，热量损失峰值时间从4月下旬推迟到6月中旬，且南半球秋季的热量损失低于正常水平。冬季地表热量损失加剧伴随着海气界面两侧的显著变化。这些变化包括大气风暴频率增加以及由地表热量损失驱动的高密度水形成，尽管这种密度增加对诸如南极底层水形成等更广泛过程的影响仍不明确。我们的研究结果表明，2023年南极海冰损失极大地改变了南大洋的海气相互作用，并促使对更广泛的气候系统影响进行深入分析。
