On Surface Waves in Arctic Seas

Surface waves in the Arctic Seas are jointly analyzed using satellite altimeter observations, classical fetch and duration laws of wave development, and a two-dimensional parametric wave model. A simplified scenario is first considered for the wave development under known physical fetch conditions during cold air outbreak events. Wave developments are found to agree well with the fetch laws, given known wave fetch and fetch-averaged wind speed, for significant wave heights (SWHs) less than 4–6 m and wind speeds below 20 m s −1 . Wind wave conditions remarkably change for moving storms, associated with rapidly evolving polar lows (PLs). For such conditions, wind-generated waves exhibit properties similar to those encountered during tropical cyclones (TCs), reaching very large SWHs (8–12 m) and long wavelengths (up to 350 m). Still, wave parametrizations based on the extended fetch concept, previously developed for TC conditions, cannot be directly applied to PL cases due to their inherent marked space–time non-stationarity. Instead, an extended duration concept for wave development under PLs is suggested. Extended duration laws provide first-guess wave parameters, based on characteristic wind speed, translation velocity, spatial scale, and duration of a PL. A 2D parametric wave model, previously developed for TC conditions, is then applied to simulate waves generated during cold air outbreaks and PLs. Comparisons with altimeter measurements are favourable making it possible to consider this simple modelling tool for fast estimates and predictions of waves generated under highly variable Arctic wind conditions.