The recent increase in Atlantic and Pacific ocean heat transports has led to a decrease in Arctic sea-ice area and volume. As the respective contributions from both oceans in driving sea-ice loss is still uncertain, our study explores this. We use the EC-Earth3 coupled global climate model and perform different sensitivity experiments to gain insights into the relationships between ocean heat transport and Arctic sea ice. In these model experiments, the sea-surface temperature is artificially increased in different regions of the North Atlantic and North Pacific Oceans and with different levels of warming. All the experiments lead to enhanced ocean heat transport, and consequently to a decrease in Arctic sea-ice area and volume. We show that the wider the domain in which the sea-surface temperature is increased and the larger the level of warming, the larger the increase in ocean heat transport and the stronger the decrease in Arctic sea-ice area and volume. We also find that for a same amount of ocean heat transport increase, the reductions in Arctic sea-ice area and volume are stronger when the sea-surface temperature increase is imposed in the North Pacific, compared to the North Atlantic. This is explained by the lower-salinity water at the Bering Strait and atmospheric warming of the North Atlantic Ocean in the Pacific experiments. Finally, we find that the sea-ice loss is mainly driven by reduced basal growth along the sea-ice edge and enhanced basal melt in the Central Arctic. This confirms that the ocean heat transport is the primary driver of Arctic sea-ice loss in our experiments.

最近大西洋和太平洋热传输的增加导致北极海冰面积和数量的减少。由于两个海洋在推动海冰损失方面的各自贡献仍不确定，因此我们的研究对此进行了探讨。我们使用EC-Earth3耦合的全球气候模型并执行不同的敏感性实验，以洞悉海洋热传输与北极海冰之间的关系。在这些模型实验中，在北大西洋和北太平洋的不同区域中，随着变暖程度的不同，海面温度被人为升高。所有的实验都导致海洋热传递的增强，从而导致北极海冰面积和体积的减少。我们表明，海表温度升高的范围越广，变暖水平越大，海洋热传输的增加幅度越大，北极海冰面积和体积的减少幅度越大。我们还发现，与北大西洋相比，在北太平洋施加海面温度升高的情况下，对于相同数量的海洋热传输增加，北极海冰面积和体积的减少更强烈。白令海峡盐度较低的海水和太平洋实验中北大西洋的大气变暖可以解释这一点。最后，我们发现海冰的流失主要是由沿海冰边缘的基础生长减少和北极中部的基础融化增加所致。这证实了海洋热传输是我们实验中北极海冰损失的主要驱动力。