Mixing by turbulent motions in the ocean is important for global ocean circulation, nutrient supply to surface waters, and the global ocean heat budget. Turbulent mixing takes the form of a diffusive process where the vertical flux is proportional to the concentration gradient with an eddy diffusivity coefficient, Kz, as a constant of proportionality. Osborn (1980) suggested that Kz is in turn related to the flux Richardson number (Rif) or mixing efficiency (G) that is commonly assumed to be a constant value of 0.2. However, recent observations have suggested a dependence of Rif on a variety of other parameters. Here, I discuss direct measurements of the buoyancy flux (and hence the mixing efficiency), the dependence of Rif, and examine the implications of a variable mixing efficiency on current estimates of mixing in the ocean.
Research into the marine systems of the world takes us to remote locations.
Engaging and educating students and citizens about Georgia's coasts and the world's oceans.
Birds at Sapelo Island
Either seasonally or permanently, shorebirds and indigenous species call this island home
Exploring the deep
Exploring the deep ocean of the Gulf of Mexico using Alvin.
Salt Marsh Ecosystems
Understanding the effects of a changing environment on salt marshes.