The Lifecycle of Marine Fog in the Coastal Zone

Fog is a collection of suspended water droplets or ice crystals in the atmospheric boundary layer that appears under favourable dynamic, thermodynamic, chemical, and surface conditions with visibility less than 1 km. Fog negatively affects society due to its ability to reduce visibility, which leads to economic losses of the same enormity of tornadoes. Notwithstanding extensive research, the ability to predict fog accurately is limited. Coastal fog is particularly difficult to predict because of the complex interactions between the lower atmosphere, upper ocean, and land surface. This dissertation presents several cases studies that aim to improve the understanding of coastal fog. The first part of the dissertation investigates a captivating fog dissipation event that was observed during the ’Fog and Turbulence Interactions in the Marine Atmosphere’ (FATIMA) project’s Grand Banks field campaign in the North Atlantic, where a fog-free region appeared immediately downstream of an islet (Sable Island) as fog advected past it. The second part concerns a mixing-fog event that appeared during the C-FOG field campaign off the coast of Newfoundland, Canada, where an oceanic cold front collided with a peninsula to produce misty/foggy conditions. In the third part of the dissertation, to aid fog prediction using numerical weather prediction models, a comprehensive set of laboratory experiments was conducted to quantify mixing as a function of the obstacle height.