CGD scientists completed 20th Century Runs of the CESM-BGC version 1.5:
As new parameterizations of eddy mixing are developed there is a need for quantitative guidance from observations and high-resolution modeling to first validate the parameterization, and second to guide the choice of free parameters. A recently developed technique for computing the global distribution of the eddy diffusivity tensor from passive tracer simulations with high-resolution global ocean models was used to develop estimates of the spatial dependence and degree of anisotropy of mixing by mesoscale eddies. These estimates were used to constrain the range of values used in simulations with prototype versions of CESM that incorporate a new anisotropic form of the Gent-McWilliams parameterization.