The Arctic has undergone perhaps the largest physical transition of any region on Earth over the past two decades as a result of increasing global greenhouse gas concentrations. Climate change has left high northern coasts susceptible to sea-level rise, wave action, and storm surge, where landfast and thick perennial sea ice once modulated coastal exposure. We are learning to incorporate mesoscale coastal physics and biogeochemistry into Earth System Models to enhance understanding of the changing state of the ocean and sea ice in relatively shallow regions (<500m) and at eddy-permitting scales. Here, we isolate one aspect of our development - that of regional mesh refinement in a fully coupled global Earth system model. Using Version 2 of the Energy Exascale Earth System Model (E3SMv2), we demonstrate the impact of mesh refinement in the proximity of Arctic coasts, and across the Arctic system. We present an analysis of the sea ice state in a simple controlled study that isolates the combined impacts of regionally-refined ocean-ice and atmosphere-land components (14km and 25km resolution respectively) as compared to standard coupled model resolution (30 and 110km resolution) in 500-year preindustrial simulations. Against a background of eddy versus non-eddy resolving ocean physics, and improved representation of Arctic storms accommodated by increased resolution, all other aspects of E3SM remain the same including column physics in each model, except for numerical changes necessitated by enhanced resolution. A robust Arctic signal emerges from these long simulations with a dramatic increase in sea ice thickness with higher resolution; no comparable change occurs for Antarctic sea ice, where resolution is nominally the same between the two simulations.