This study investigates the impact of sea ice and snow changes on surface air temperature (SAT) trends on the multidecadal time scale over the mid- and high-latitudes of Eurasia during boreal autumn, winter and spring based on a 30-member ensemble simulations of the Community Earth System Model (CESM). A dynamical adjustment method is used to remove the internal component of circulation-induced SAT trends. The leading mode of dynamically adjusted SAT trends is featured by same-sign anomalies extending from northern Europe to central Siberia and to the Russian Far East, respectively, during boreal spring and autumn, and confined to western Siberia during winter. The internally generated component of sea ice concentration trends over the Barents-Kara Seas contributes to the differences in the thermodynamic component of internal SAT trends across the ensemble over adjacent northern Siberia during all the three seasons. The sea ice effect is largest in autumn and smallest in winter. Eurasian snow changes contribute to the spread in dynamically adjusted SAT trends as well around the periphery of snow covered region by modulating surface heat flux changes. The snow effect is identified over northeast Europe-western Siberia in autumn, north of the Caspian Sea in winter, and over eastern Europe-northern Siberia in spring. The effects of sea ice and snow on the SAT trends are realized mainly by modulating upward shortwave and longwave radiation fluxes.

这项研究基于对30个成员的整体模拟，调查了北冰洋，秋冬和春季中高纬度欧亚大陆中高纬度海冰和积雪变化对地表气温（SAT）趋势的影响。社区地球系统模型（CESM）。动态调整方法用于消除循环引起的SAT趋势的内部成分。动态调整SAT趋势的领先模式的特点是，同等符号异常分别在春季和秋季期间从北欧延伸到西伯利亚中部和俄罗斯远东，并在冬季局限于西伯利亚西部。在所有三个季节中，Barents-Kara海域内海冰浓度趋势的内部产生成分导致了整个西伯利亚北部整个集合体内部SAT趋势的热力学成分差异。在秋季，海冰效应最大，而在冬季，海冰效应最小。欧亚的积雪变化通过调节表面热通量变化，促进了动态调整的SAT趋势以及积雪区域周围的分布。降雪效果在秋季被确定为在东北北欧-西伯利亚，冬季在里海以北，在春季为东欧-北西伯利亚。海冰和雪对SAT趋势的影响主要是通过调制向上的短波和长波辐射通量来实现的。