Beaufort Sea storm and resuspension modeling

Along the shallow Beaufort Sea coast of the Arctic Ocean, storm events during the summer are responsible for significant sediment resuspension and transport. Given the paucity of data in this difficult field area, a model has been developed to be used as a tool towards investigation of these processes. Two contrasting set of conditions are modeled; one simulation for a relatively quiescent period and a second simulation for a period that included a moderate and typical northwesterly storm. Results for these two periods are compared with shallow-water current and wave data collected by instrumented moorings. For the calm period, the model did not predict specific events very well, whereas for the period with a strong storm, the model performed very well in predicting wave height and wave period, and less well in predicting currents. However, under both calm and stormy conditions, mean current speeds and mean current directions were predicted with sufficient accuracy to proceed to calculations of sediment transport. Sensitivity analysis showed that currents contribute very little to the wave dominated resuspension, but mean currents could be used for computing sediment transport quantities and directions. Measurements of storm surge were represented well by the model output, aligning perfecting with the building and waning storm, but with a slight overprediction at the peak of the storm. The reasonable reproduction of wave heights and periods, and of storm surge indicate that the model is responding well to the input parameters. The modeling suggests that the most significant sediment erosion occurs at the northern tips of the Mackenzie Delta and the Tuktoyaktuk Peninsula, and around the area of Herschal Island. The model also indicates that waves are not fully developed during a storm for the present day ice limited fetch, and that extending the fetch a further 100 km to simulate ice retreat led to wave heights at the coast being increased by 20 cm.