Surface heat budget in an oceanic simulation using data from Tropical Ocean‐Global Atmosphere Coupled Ocean‐Atmosphere Response Experiment

Abstract

A three‐dimensional regional ocean model is used to investigate the response of the upper ocean to different atmospheric weather events encountered during the Tropical Ocean‐Global Atmosphere Coupled Ocean‐Atmosphere Response Experiment (COARE). The basic model is a version of the ocean general circulation model developed at the Laboratoire d'Océanographie Dynamique et de Climatologie in Paris and includes open lateral boundaries and a 1.5 level order turbulence closure scheme. The horizontal grid spacing is 0.1° in longitude and 0.08° in latitude. There are 29 vertical levels, with a resolution of 5 m near the top. The surface atmospheric forcing used comes from a combination of European Centre for Medium‐Range Weather Forecasts model output and estimates from bulk parameterization. The data set collected during the Intensive Observation Period enables a detailed initialization of the model. The analyses of the model output show that most features are in good agreement with the observations. During westerly wind bursts the mixed layer heat budget is negative (−83 W m−2) over a larger part of the COARE domain mainly because of the strong latent heat flux and weak solar radiation. Strong inhomogeneities due to local importance of horizontal advection contrast with relative homogeneous net heat flux. In this period all terms of the heat balance are active in the oceanic mixing layer. During the calm period the budget is weakly positive (15 W m−2) but still remains patchy because of the contribution of horizontal advection.