Abstract

Physical oceanographers have known for several decades the total amount of abyssal mixing and upwelling required to balance the deep-water formation, but are still working to understand the mechanisms and locations-how and where it happens. From observational studies, we know that areas of rough topography are important, and the hundreds of Grand-Canyon sized canyons that line mid-ocean ridges have particularly energetic mixing.

This talk will present results from a fluid dynamics study of diffusive boundary layers interacting with varying topography, showing mechanisms by which rough topography translates into energetic currents and mixing. These boundary layer interactions can both increase the total amount of mixing near topography and can provide a mechanism for exchanging mixed boundary water with the stratified far field. These boundary layer processes may be a source of a dynamically important amount of abyssal upwelling, profoundly affecting predictions of the basin-scale circulation.