The Effect of Sea Ice on Tidal Propagation in the Kitikmeot Sea, Canadian Arctic Archipelago

The tides in the Kitikmeot Sea, in the southern Canadian Arctic Archipelago, are found to be heavily influenced by seasonal sea-ice formation and blocking in a strait. Data from a moored current profiler in Dease Strait exhibit strong tidal damping during wintertime seasonal sea-ice cover, with 50%-60% reduction in tidal elevation and 65% reduction in tidal velocities. We used a 3D unstratified barotropic numerical tidal model of the region to show that the observed wintertime tidal damping likely requires both high sea-ice friction and a partial sea-ice blockage in Victoria Strait (VS), the eastern gateway of the Kitikmeot Sea, where tidal-induced ridging causes thick, rough ice to accumulate over its shallow sill. Our analysis of the model shows different dynamics for the M-2 and K-1 tides. Both tidal constituents are dominated by the Atlantic tides entering through VS. Overall, similar to 90% of the M-2 tidal energy entering VS does not reach Dease Strait because, in addition to dissipation in VS (similar to 25%), it is significantly diverted into adjoining bays and around an amphidrome in eastern Queen Maud Gulf (similar to 65%). In contrast, the smaller K-1 tide is less diverted into the subsidiary channels, after similar to 20% dissipation in VS and only similar to 25% in adjoining bays, it propagates far into the region and is amplified due to resonance in Dease Strait and Coronation Gulf, resulting in larger tidal height than the M-2 tide in Coronation Gulf.

Automated summary

Tides in the Kitikmeot Sea are heavily influenced by seasonal sea-ice formation and blocking in a strait, leading to significant tidal damping during wintertime sea-ice cover. The dynamics of the M-2 and K-1 tides show different patterns, with both tidal constituents dominated by Atlantic tides entering through Victoria Strait. The smaller K-1 tide is less diverted into subsidiary channels compared to the M-2 tide, propagating further into the region and resulting in larger tidal height in Coronation Gulf.