科学家们一直担心,随着气候变化情况恶化,来自北极地区的冰冷海水可能把欧洲冰冻,即欧洲局部地区温度下降、海港封冻。但最新一期英国《自然》杂志刊登研究报告说,这种预测有疏漏。 e-taBrl;
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领导这项研究的美国迈阿密大学研究人员丽莎·比尔说,欧洲冰冻的预测忽视了另外一股洋流——“厄加勒斯暖流”的影响。这股暖流源自非洲南端印度洋与大西洋交汇处。实地观测和计算机模拟的综合结果显示,随着气候变化,“厄加勒斯暖流”对于欧洲气候的影响不断增强,它会把温暖的海水从印度洋带入大西洋。 <IX)D `mf
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西欧沿海地区的温度比北半球许多同纬度地区要高,原因是“北大西洋暖流”每年从赤道带来大量温暖的海水。但联合国政府间气候变化专门委员会(IPCC)等机构曾预测,气候变化会使北极地区的冰大量融化,大量冰冷的海水流入大西洋,减弱“北大西洋暖流”的效果,导致欧洲和北美部分地区温度大幅下降。 HfF4BQxm
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丽莎·比尔认为,自己的研究表明包括IPCC等权威机构在内的气候变化预测都有存在缺陷的可能。她说,对非洲等地区海域的观测数据现在仍然偏少,应该进一步加强对“厄加勒斯暖流”等的监测,以更加详细的数据来为气候变化决策提供参考。 LB)sk$)
The Atlantic Ocean receives warm, saline water from the Indo-Pacific Ocean through Agulhas leakage around the southern tip of Africa. Recent findings suggest that Agulhas leakage is a crucial component of the climate system and that ongoing increases in leakage under anthropogenic warming could strengthen the Atlantic overturning circulation at a time when warming and accelerated meltwater input in the North Atlantic is predicted to weaken it. Yet in comparison with processes in the North Atlantic, the overall Agulhas system is largely overlooked as a potential climate trigger or feedback mechanism. Detailed modelling experiments—backed by palaeoceanographic and sustained modern observations—are required to establish firmly the role of the Agulhas system in a warming climate.