Numerical simulation of sea spray turbulent transport at the marine boundary layer*

In this study, we perform large-eddy simulations (LES) combined with Lagrangian particle tracking to investigate the turbulent flow and transport of spray droplets over realistic waves at the lower boundary. We prescribe spatial wave data as the lower boundary condition, which is obtained by transforming the temporal data from a wind-wave tank experiment at the Pytheas Institute in France. The sea spray generation function (SSGF) introduced by this experimental study is implemented into the droplet-laden LES model. The SSGF creates a wide range of low to intermediate inertia droplets at the water surface. It is estimated using the flux profile method, where the droplet concentrations are measured at a fixed height to estimate spray fluxes at the surface by assuming a vertical concentration profile shape. We aim to verify if the method is adequate at the wave boundary layer. LES are performed for a shear velocity of 1.01 m/s corresponding to a 10-meter wind speed 20 m/s. We compare the droplet concentration profiles from our model with experimental results. Alongside the Eulerian scheme, we discuss the findings from the droplets and wave-induced turbulence statistics, which give us insights into the transport of spray droplets and how this relates to droplet dispersion theories.