Ocean transition layer characteristics based on the Arabian sea mooring data

Ocean models are sensitive to the way the along isopycnal mixing dominated mesocale interior connects to the vertically well mixed surface boundary layer. The transition from the mixed layer to the interior occurs in a transition layer whose basic characteristics are now being investigated using data. Ocean General Circulation Model studies (Danabasoglu et al 2008) have shown that transition layer characterizations are important for climate simulations. A recent study by Johnston and Rudnick (2008) has characterized the transition layer using Seasoar data. Here we characterize the transition layer thickness in terms of the statistics of thickness of enhanced stratification and shear regions below the mixed layer, as well as the depth of penetration of the wind stress using Arabian sea mooring data. In addition, the transition layer variations are related to the surface fluxes of momentum and heat during time intervals when heat budgets are one dimensional.