Simulation of the Pacific equatorial thermocline with an ocean general circulation model

Abstract

The reproduction of equatorial thermocline characteristics by numerical models is of great importance for seasonal forecasts, and it is also a key factor in operational ocean forecasting. Due to difficulties in the numerical description of adiabatic eddy processes, the model thermocline is usually diffused and shifted in depth. In this work, we perform a numerical experimental study of the sensitivity of the Pacific equatorial thermocline to horizontal and vertical mixing parameterizations in the INMIO ocean general circulation model. It has been shown that the sharpness and location of the thermocline can be improved by a combined parameterization of eddy mixing and isopycnal diffusion, as well as by proper tuning of the background coefficient of vertical diffusion.