Abstract: A generalised Osborn-Cox relation

 

 

Authors: D. Olbers, C. Eden, R. Greatbatc

The generalised Transformed Residual Mean (TRM-G) framework is reviewed andillustrated using a numerical simulation of vertical shear instability. It is shown how TRM-G reveals the physically relevant amount of diapycnal eddy uxes and implied diapycnal mixing, and how TRM-G relates to the Osborn-Cox relation, which is often used to obtain observational estimates of the diapycnal diffusivity. An exact expression for the diapycnal diffusivity in TRM-G is given in the presence of molecular diffusion, based on acknowledging and summing up an entire hierarchy of eddy buoyancy moments.