Eddy-mixed layer interactions in the ocean

Numerical models have become essential tools in the study and prediction of natural climate variability and anthropogenic climate change. However the skill of such models in simulating the observed climate variability is still severely limited by (1) numerical approximations in the discretization of the hydrodynamical equations and (2) imperfect parameterizations of the myriad of atmospheric and oceanic processes that happen at scales too small to be explicitly resolved by the model. In the 1960s, at the dawning of the age of numerical modeling, the accuracy of the numerical schemes was the real bottleneck. For example, early models of the ocean generated excessive mixing across density surfaces due to poor numerical discretization. Great strides have been made over the past four decades in overcoming these technical difficulties both through improvement of the numerical codes and through increase in computational power. Currently the major source of model error has become the imperfect or missing parameterization of unresolved processes.