UBC Math Department Colloquium: Luc Deike

Ocean waves forced by wind grow and eventually break, playing an important role in the coupling between the atmosphere and the ocean. Wave breaking modulates momentum and energy fluxes, controlling upper ocean currents affecting gas transfer and pollutant dispersion while air entrained by wave breaking modulates gas exchange and bursting bubbles contribute to the emission of sea spray aerosols to the atmosphere. Wind growth and wave breaking can be characterized by focusing on single events. However, the inherently multiscale nature of wind-forced wave breaking presents challenges for accurately characterizing the wave field, in terms of balance between wind input, nonlinear wave interactions, and dissipation due to breaking, as well as the associated turbulence generation. I will discuss recent efforts in bridging theoretical description of wind wave forcing and wave breaking at the level of individual events leveraging high resolution simulations at the meter scale with statistical representation of broad-banded wave fields, based on a recently developed multilayer framework to resolve broadband wave fields with waves spanning from O(1) to O(100) m. The resulting physical description of wind-wave breaking serves as basis to constrain air-sea fluxes at large scale and provides a path to incorporate waves' effects in parameterization used in ocean and earth system models.