A novel approach to the rapid formation of a deep layer of marine fog and cloud in the NW Atlantic is proposed. On July 13-14, 2019, a deep layer of fog and cloud extending to 2 km height was observed over Sable Island off the coast of Nova Scotia in Atlantic Canada. This fog and cloud event was dominantly caused by the rapid penetration of a trough from a cyclone over northeastern Canada.
The trough moved rapidly from SW-W to E-NE and entered the coastal waters of Nova Scotia. There was no evidence of an advection-type fog mechanism as the surface air temperature was not adjusted to the colder sea-surface temperature leading to saturation of the near-surface air.
Darko Koračin,
University of Split, Croatia
The front part of a massive cloud band in the trough that passed over Sable Island generated precipitation prior to fog formation. The rain evaporated in the unsaturated and warm subcloud layer, effectively lowered the air temperature, significantly increased the wet-bulb temperature in this layer, and caused fog to form.
In summary, the development of this deep layer of fog and cloud in the NW Atlantic was caused by evolving synoptic conditions, the simultaneous effects of a rapid trough incursion over coastal waters with a massive cloud band, induced precipitation leading to cloud lowering into the subcloud layer, and the convergence of near-surface winds leading to vertical mixing in a stable marine boundary layer.
While working at the Desert Research Institute in Reno, Nevada, at the University of Split, Croatia, and recently as a visiting professor at UND, Dr. Koračin has conducted research and teaching activities in the field of atmospheric sciences.
In addition to observational analyses, his expertise includes the development and application of high-resolution mesoscale meteorological and dispersion models, fluid mechanics models, and global and regional climate models. His main research interests are air-sea interaction and coastal atmospheric and cloud dynamics with a focus on the formation, evolution, and dissipation of marine fog based on observations and modeling.
Dr. Koračin has served as a principal or co-principal investigator on many research projects in the US and abroad on fog, coastal and ocean dynamics, air pollution, complex terrain flows, radiation and turbulence processes, renewable energy, and climate processes over land and sea.