The Atlantic Multidecadal Oscillation (AMO) has garnered attention for its important role in shaping surface air temperature (SAT) patterns over Eurasia. While Eurasian winter SAT was traditionally attributed to changes in large-scale atmospheric circulations associated with the AMO, a careful examination of the latest unforced CMIP6 simulations in this study unveils a significant contribution of the AMO’s thermodynamic effects. Specifically, the heat released from the North Atlantic Ocean and transported to northern Eurasia through westerlies takes precedence over the effect of dynamic Rossby waves, resulting in warm (cold) phases during positive (negative) AMO cycles, along with increased (decreased) warm extremes and reduced (enhanced) cold extremes. This study contributes to an improved understanding of the dominating mechanism of the AMO’s impact on Eurasian SAT.

大西洋数十年涛动（AMO）因其在塑造欧亚大陆表面气温（SAT）模式方面的重要作用而受到关注。虽然欧亚冬季 SAT 传统上归因于与 AMO 相关的大规模大气环流的变化，但对本研究中最新的非受迫 CMIP6 模拟的仔细检查揭示了 AMO 热力学效应的重大贡献。具体来说，从北大西洋释放并通过西风带输送到欧亚大陆北部的热量优先于动态罗斯比波的影响，导致正（负）AMO循环期间出现暖（冷）阶段，并伴随着极端温暖的增加（减少）并减少（增强）极端寒冷。这项研究有助于更好地理解 AMO 对欧亚 SAT 影响的主导机制。