The role of environmental turbulence in the lifecycle of marine fog

Marine fog raises numerous visibility issues for aviation, seafaring and directed energy applications, making its understanding and prediction imperative in many areas including transportation, emergency response and defense. Nevertheless, accurately simulating and predicting the onset, duration, and dissolution of sea fog remains a highly challenging problem, due in large part to sensitivity of the fog lifecycle to microphysical processes, including atmospheric surface-layer turbulence and physicochemical properties of aerosols on which fog droplets develop. Here, to describe fog droplet activation and growth more accurately, the classical Köhler analysis is extended to include the role of viscous-convective straining motions of Kolmogorov eddies that encapsulate the fog condensation nuclei. Under this formulation, the new droplet equilibrium is possible at a radius explicitly determined by the TKE dissipation rate. Relevant fog-turbulence interaction mechanisms are discussed in this presentation with data taken during the Fog and Turbulence Interactions in the Marine Atmosphere (FATIMA) campaign using the novel super combo probe, where simultaneous velocity and temperature measurements were made down to the microscales during both clear and foggy conditions for the first time.