A modelling study of the ice-free tidal dynamics in the Canadian Arctic Archipelago

Abstract

The dynamics of M2 and K1 ocean tides in the Canadian Arctic Archipelago (CAA) have been investigated using a three-dimensional hydrodynamic model, which uses an unstructured mesh with a horizontal resolution ranging from 0.5 km in narrow channels to 10–40 km in the open ocean. The model is evaluated against observed tidal elevations and tidal currents, and the evaluation indicates that the model is able to reproduce the observations at the tidal gauge sites, particularly those in the narrow straits of the CAA. In order to examine the interactions between the Arctic and the Atlantic tides in the CAA, idealized experiments were conducted by considering tidal effects through the open boundary on the Arctic and the Atlantic sides separately. The results show that the Atlantic tide is strong throughout the CAA but deceases rapidly when it encounters the open Arctic shelf for both M2 and K1 tides; on the other hand, the Arctic tide is mainly confined to the Arctic Ocean and Amundsen Gulf; it has a minor influence in the Baffin Bay. Nonlinear interactions between the Arctic and Atlantic tides are generally weak except local areas in the southern and northern CAA, where the nonlinear contribution is able to reach 10–20% of the tidal variability. Using the model results, the tidal energy flux was also analyzed, and the analysis indicated that the Lancaster Sound and Jones Sound are main pathways of the tidal energy from the Baffin Bay to the CAA, and the energy is dissipated due mainly to the vertical diffusion and the bottom friction.