Faculty of Environmental Earth Science, Hokkaido University, Hokkaido, 060-0810, Japan.
Faculty of Science, Niigata University, Niigata, 950-2181, Japan.
Nat Commun. 2019 Nov 8;10(1):5111. doi: 10.1038/s41467-019-13124-2.
Amplified Arctic warming and its relevance to mid-latitude cooling in winter have been intensively studied. Observational evidence has shown strong connections between decreasing sea ice and cooling over the Siberian/East Asian regions. However, the robustness of such connections remains a matter of discussion because modeling studies have shown divergent and controversial results. Here, we report a set of general circulation model experiments specifically designed to extract memory effects of land processes that can amplify sea ice-climate impacts. The results show that sea ice-induced cooling anomalies over the Eurasian continent are memorized in the snow amount and soil temperature fields, and they reemerge in the following winters to enhance negative Arctic Oscillation-like anomalies. The contribution from this memory effect is similar in magnitude to the direct effect of sea ice loss. The results emphasize the essential role of land processes in understanding and evaluating the Arctic-mid-latitude climate linkage.
北极地区的变暖幅度在不断加大，这与冬季中纬度地区的降温现象有着密切的关系，这一现象已经引起了广泛的关注。观测结果表明，北极海冰的减少与西伯利亚/东亚地区的降温之间存在紧密的联系。然而，由于模型研究结果存在分歧和争议，这种联系的可靠性仍然存在争议。在这里，我们报告了一组特定的环流模型实验结果，这些实验旨在提取陆地过程的记忆效应，以放大海冰对气候的影响。结果表明，欧亚大陆上由海冰引起的冷却异常在雪量和土壤温度场中被记忆，并在下一个冬季重现，以增强类似北极涛动的负异常。这种记忆效应的贡献与海冰损失的直接效应相当。研究结果强调了陆地过程在理解和评估北极与中纬度气候联系中的重要作用。
