Fig. 5: Improvements in navigation metrics by refining sea ice simulations.

a and b present the ratios of positive (\({R}_{{PD}}\)) and negative (\({R}_{{ND}}\)) differences for Polar Class 6 (PC6) and Open Water (OW) ships. These ratios are calculated against the reference dataset (REF). A ratio of 0 suggests the experiment closely matches REF results. c–f illustrate improvements in estimating the fastest trans-Arctic shipping routes in October, derived from optimizing sea ice concentration (Opt_SIC) and thickness (Opt_SIT), respectively. The black pentagram shows the location of the North Pole.