The Arctic climate is changing rapidly, along with intensified melting of sea ice, which has significant impacts on surface air temperature (SAT) in Eurasia. This study reveals that the subseasonal response of SAT to the autumn Kara–Laptev Sea ice (KLSIC) differs significantly between early and late winter. The response of SAT to KLSIC forms a warm Arctic–cold Eurasia pattern in early winter. Conversely, the negative anomaly response of SAT to KLSIC in late winter is only distributed in the band range of Eurasia, without significant positive SAT anomaly over the Arctic Ocean. After further examination of the separate physical mechanisms involved in early and late winter, it is found that a decrease in KLSIC in autumn can lead to a strengthened Ural high and Siberian high in the Arctic–Eurasia region, which is conducive to cold events in the mid-latitudes of Eurasia in early winter. For late winter, a westward shift in the response of atmospheric circulation to KLSIC leads to a negative anomaly feedback of North Sea surface temperature, which triggers the propagation of Rossby waves to the Sea of Japan through the wave activity flux. Meanwhile, the deep trough of East Asia is strengthened and extends to the southeast, guiding northern cold air to the western Pacific. Our results highlight that different subseasonal effects of sea ice should be considered in Eurasian climate prediction, rather than only consider the effects in winter mean.

中文翻译：

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欧亚大陆早冬和晚冬地表气温对秋季卡拉-拉普捷夫海冰的不同响应

北极气候正在迅速变化，海冰融化加剧，对欧亚大陆的表面气温（SAT）产生重大影响。这项研究表明，SAT 对秋季卡拉-拉普捷夫海冰 (KLSIC) 的次季节响应在冬初和冬末之间存在显着差异。 SAT对KLSIC的响应在初冬形成了温暖的北极-寒冷的欧亚大陆格局。相反，晚冬 SAT 对 KLSIC 的负异常响应仅分布在欧亚大陆波段范围内，北冰洋上空没有显着的 SAT 正异常响应。进一步考察初冬和晚冬涉及的单独物理机制后发现，秋季KLSIC的减少会导致北极-欧亚地区乌拉尔高压和西伯利亚高压的加强，有利于北极地区寒冷事件的发生。初冬的欧亚大陆中纬度地区。冬末，大气环流对KLSIC响应的西移导致北海表面温度负异常反馈，从而触发罗斯贝波通过波浪活动通量传播到日本海。与此同时，东亚深槽加强并向东南延伸，引导北方冷空气进入西太平洋。我们的结果强调，在欧亚气候预测中应考虑海冰的不同次季节影响，而不是仅考虑冬季平均值的影响。