Counter-Gradient Term Applied to the Turbulence Parameterization in the BRAMS

The numerical weather prediction is a routine in operational meteorological centers, where sophisticated computer models are executed. The atmospheric dynamics is simulated by solving the Navier-Stokes equations, considering several physical phenomena. One parameterization applied to this dynamical system is to represent the turbulence. A counter-gradient flow can be described for higher order closure turbulence approaches. Here, a first order parameterization for the turbulent flow is coupled with an explicit counter-gradient term. Both latter schemes are based on the Taylors statistical theory of turbulence. The parameterization schemes are applied to the BRAMS, a mesoscale meteorological model. The simulation is compared with experimental data measured in the Brazilian Amazon region.