We introduced a modulating factor to the surface heat flux in the EC-Earth3 model to address the lack of parameterization for turbulent exchange over sea ice leads and correct the bias in Arctic sea ice. Three pairwise experiments showed that the amplified heat flux effectively reduces the overestimated sea ice, especially during cold periods, thereby improving agreement with observed and reanalysis data for sea ice area, volume, and ice edge, particularly in the North Atlantic sector.