Impact of Droplets on Latent and Sensible Heat Flux at the Air-Sea Interface

Sea-spray droplets ejected into the air take part in a series of complex physical processes which lead to the modification of mass, momentum, and energy exchange at the air-sea interface, particularly in extreme conditions. Details of these processes, which include droplet formation, turbulent transport, and thermodynamic evolution, remain obscured but have potentially huge influences on a variety of atmospheric and oceanic applications. While current models have sought to capture the general bulk influence of spray droplets, a solid, process-level understanding of the physics behind these models needs to be established. To address this, direct numerical simulations (DNS) of turbulent air flow are implemented with two-way coupled Lagrangian evaporating droplets. Specifically, turbulent open-channel flow is simulated with particles being injected from the lower boundary in such a way that maintains a constant mass loading of droplets in the domain. Droplet size and concentration are then systematically varied in order to investigate the fate of specific classes of droplets and their feedback mechanisms on the surrounding air. This presentation will deliver some insights for the droplet-induced modifications to both sensible and latent heat fluxes, which in the future will be used to refine and develop parameterizations aimed at characterizing the role of sea spray in the marine air boundary layer.