Shallow flows in the atmosphere and oceans: Geophysical and engineering applications

There are many naturally occurring flows in the atmosphere and oceans with large horizontal scales compared to the vertical scale (i.e. shallow water flows), some examples being large scale synoptic and meso-scale flows, regions of stratified turbulence (e.g. thermocline and stable atmospheric boundary layers) and flows over sloping surfaces. Engineered flows in stably stratified regions of the atmosphere and oceans also fall into the category of shallow flows, which include wakes of underwater vehicles and structures, jets and plumes from waste outfalls and releases, and plume-stack releases in the atmosphere. This paper first outlines some cases of stratification induced natural shallow flows, paying particular attention to stratified turbulence, boundary layer flows over sloping terrains and their modeling implications. Engineered flows in the environment are discussed next, with reference to wakes of self-propelled bodies in oceanic diurnal and permanent thermocline.