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Because of large internal variabilities, the role of Arctic sea ice concentration (SIC) on regional climate cannot be easily separated. This study uses two groups of large ensemble atmospheric model simulations under climatological and observed SIC boundary conditions to investigate the role of SIC in the 2014-2015 December to February Eurasian warm winter (DJF15). It is shown that the SIC has large impact on the probability distribution function of the DJF15 temperature and pressure fields. The anomalous high Barents Sea ice during the 2014-2015 autumn and winter leads to significant shift in the probability distribution function skewness of the DJF15 surface temperature (from -0.13 to -0.48) and the related sea level pressure (from -0.18 to 0.32) that favor more occurrences of warm temperature anomaly and positive North Atlantic Oscillation-like pattern. This asymmetry is consistent with anomalous forcing in phase with the anomalies of the sea level pressure field.

Plain Language Summary Anomalous Arctic sea ice regulates heat exchanges between the ocean and atmosphere, thereby modifying the equator-pole temperature gradient and affecting the atmospheric circulation and weather patterns at southern latitudes. In this study, we utilize large ensemble numerical simulations to investigate the role of Arctic sea ice on the Eurasian warm winter in 2014-2015. Our analysis shows that the sea ice forcing shifts the skewness of the simulated event-related temperature and sea level pressure, resulting in asymmetrical forcing on the related sea level pressure depending on the atmospheric state. These results emphasize the importance of analyzing beyond the mean and variance in fully characterizing sea ice forcing on atmosphere, which are essential for regional weather pattern prediction and climate risk assessments.