Recent studies point to the sensitivity of mid-latitude winter climate to Arctic sea ice variability. However, there remain contradictory results in terms of character and timing of Northern Hemisphere large-scale circulation features to Arctic sea ice changes. This study assesses the impact of realistic late autumn eastern Arctic sea ice anomalies on atmospheric wintertime circulation at mid-latitudes, pointing to a hidden potential for seasonal predictability. ​Using a dynamical seasonal prediction system, an ensemble of seasonal forecast simulations of 23 historical winter seasons is run with reduced November sea ice cover in the Barents-Kara Seas, and is compared to the respective control seasonal hindcast simulations set. ​A non energy-conserving approach is adopted for achieving the desired sea ice loss, with artificial heat being added conditionally to the ocean surface heat fluxes so as to inhibit the formation of sea ice during November. Our results point to a robust atmospheric circulation response in the North Pacific sector, similar to previous findings on the multidecadal timescale. Specifically, an anticyclonic anomaly at upper and lower levels is identified over the eastern midlatitude North Pacific, leading to dry conditions over the North American southwest coast. The responses are related to a re-organization (weakening) of west-Pacific tropical convection and interactions with the tropical Hadley circulation. ​A possible interaction of the poleward-shifted Pacific eddy-driven jet stream and the Hadley cell is discussed​. ​The winter circulation response in the Euro-Atlantic sector is ephemeral in character and statistically significant in January only, corroborating previous findings of an intermittent and non-stationary Arctic sea ice-NAO link during boreal winter. These results ​aid our understanding of the seasonal impacts of reduced eastern Arctic sea ice on the midlatitude atmospheric circulation with implications for seasonal predictability in wintertime.

最近的研究指出中纬度冬季气候对北极海冰变化的敏感性。然而，在北半球大尺度环流特征对北极海冰变化的特征和时间上，仍存在矛盾的结果。这项研究评估了现实的深秋东部北极海冰异常对中纬度冬季大气环流的影响，指出了季节性可预测性的潜在潜力。使用动态季节性预测系统，在 11 月巴伦支 - 卡拉海的海冰覆盖减少的情况下运行 23 个历史冬季的季节性预测模拟集合，并与各自的控制季节性后报模拟集进行比较。采用非节能方法来实现所需的海冰损失，有条件地向海洋表面热通量添加人工热量，以抑制 11 月期间海冰的形成。我们的结果表明北太平洋地区的大气环流响应强劲，类似于之前在几十年时间尺度上的发现。具体而言，在北太平洋东部中纬度地区发现了上下层的反气旋异常，导致北美西南海岸的干燥条件。这些响应与西太平洋热带对流的重组（减弱）以及与热带哈德利环流的相互作用有关。讨论了向极移动的太平洋涡驱动急流和哈德雷单元之间可能的相互作用。欧洲-大西洋部门的冬季环流响应是短暂的，仅在 1 月份具有统计意义，这证实了之前对北极冬季期间间歇性和非平稳的北极海冰-NAO 链接的发现。这些结果有助于我们了解北极东部海冰减少对中纬度大气环流的季节性影响，并对冬季的季节性可预测性产生影响。