Modulation of Bubble-Mediated CO2 Gas Transfer Due To Wave-Current Interactions

Abstract

Wave breaking modulates air-sea fluxes of energy, momentum, heat, and gases. Building on recent advances in the modeling of CO2 gas exchange and wave breaking, we investigate the variability of bubble-mediated gas transfer coefficients due to wave-current interactions. Submesoscale current gradients strongly modulate wave breaking, which can enhance the bubble-mediated gas transfer coefficient along temperature fronts and cold filaments. The enhancement of the gas transfer coefficient is over relatively small areas averaging out over larger regions. However, the correlation between positively anomalous gas transfer coefficients and regions with strong downwelling could potentially enhance CO2 exchange over regions with increased submesoscale activity. An empirical scaling based on the mean wave period, root-mean-square current gradients, and friction velocity can explain the root-mean-square differences of gas transfer coefficients computed from solutions with and without current forcing.