Simulated wave evolution and coastal erosion in the Arctic and the Canadian Arctic Archipelago (2002-2022)

In the Arctic, ocean surface waves are becoming more energetic. This is due to the larger wind fetch caused by decreased sea ice cover in summer and delayed sea ice formation in fall. These changes, driven by global climate change and regional warming, are projected to be more extreme in the future. Surface gravity waves are a key factor in coastal erosion and flooding, which are already negatively affecting coastlines in the Arctic (Casas-Prat & Wang 2020). Understanding and quantifying surface waves evolution is therefore particularly important for the communities that live along the coasts of the Canadian Arctic Archipelago (CAA), yet it has not been investigated with modeling.

We used the spectral wave model Wavewatch III® (Tolman 1997, 1999a, 2009) to simulate gravity waves formation and propagation for the entire Arctic and the North Atlantic over 2002-2022, using output from a regional 1/4° NEMO simulation. Simulations reveal a positive wave height trend in Baffin Bay and locations near the sea ice margin in the Barents, Kara and East Greenland Seas. A positive trend is found in Baffin Bay from June to October (max 0.25 m/y), where peak wave heights of 4-6 m are also observed during fall, in the second decade of the run. This highlights the importance of combined delay in seasonal sea ice formation and storm activity in the CAA, with storms more likely to produce high waves conditions during fall.

Further ongoing work will: 1) analyze the impact of waves on coastal erosion; 2) project ocean and wave conditions under CMIP6 forcing: the numerical ocean model NEMO, at 1/4° resolution, and a nested grid over the CAA will allow WW3 wave simulations to be projected over 2100.