南極海冰2016年達(dá)到最低點(diǎn)，可能是人類活動所致
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南極海冰面積（sea ice extent, SIE）自1979年以來呈現(xiàn)上升趨勢，但在2016年南半球春季期間急劇減少，至2016年12月達(dá)到歷史最低。
2019年1月2日, 來自澳大利亞氣象局的Guomin Wang團(tuán)隊在《自然-通訊》期刊發(fā)表的一項研究“Compounding tropical and stratospheric forcing of the record low Antarctic sea-ice in 2016”中指出，大氣與海洋現(xiàn)象的組合在此次海冰面積減少中發(fā)揮了主要作用。
異常的大氣環(huán)流最初是由印度洋和西太平洋上的熱帶強(qiáng)對流驅(qū)動的，這導(dǎo)致了南極洲周圍形成三波環(huán)流模式，使得印度洋、羅斯海區(qū)和別林斯高晉海區(qū)的海冰面積減少。隨后，極地平流層渦流顯著減弱，導(dǎo)致極地表面西風(fēng)帶大幅減弱，這進(jìn)一步使得印度洋和太平洋海區(qū)海冰面積減少。
這些過程似乎反映出異常的大氣-海洋內(nèi)部變化性。然而，熱帶印度洋的變暖趨勢（可能部分是由人類活動所致）可能在一定程度上加劇了2016年海冰面積減少的嚴(yán)峻程度。
論文相關(guān)信息
摘要：After exhibiting an upward trend since 1979, Antarctic sea ice extent (SIE) declined dramatically during austral spring 2016, reaching a record low by December 2016. Here we show that a combination of atmospheric and oceanic phenomena played primary roles for this decline. The anomalous atmospheric circulation was initially driven by record strength tropical convection over the Indian and western Pacific Oceans, which resulted in a wave-3 circulation pattern around Antarctica that acted to reduce SIE in the Indian Ocean, Ross and Bellingshausen Sea sectors. Subsequently, the polar stratospheric vortex weakened significantly, resulting in record weakening of the circumpolar surface westerlies that acted to decrease SIE in the Indian Ocean and Pacific Ocean sectors. These processes appear to reflect unusual internal atmosphere-ocean variability. However, the warming trend of the tropical Indian Ocean, which may partly stem from anthropogenic forcing, may have contributed to the severity of the 2016 SIE decline.
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