The effects of the parameterization of physical processes in the Argentine Naval Meteorological service five-level model

In this paper, the analysis of the impact of the parameterization of physical processes in the SMARA (Servicio Meteorológico de la Armada de la República Argentina) quasi-geostrophic five-level model is presented for 1–10 January 1988 and 1–10 July 1988. The physics of the model concentrates on three general areas: frictional dissipation, diabatic heating in the w-equation, and moisture sources and sinks in the moisture equation. rms of frictional dissipation are parameterized in the model: surface skin friction (the momentum losses due to surface drag) and the internal friction due to vertical shear (momentum change due to wind shear between the model layers). The diabatic heating term in the ω-equation is obtained as a result of a number of parameterizations: vertical diffusion of heat, dry adiabatic adjustment, surface sensible heat flux, radiation, large-scale precipitation, small-scale cumulus parameterization, and moist adiabatic adjustment. The time change of specific humidity is partially determined by the vertical diffusion of moisture, the surface moisture flux, as well as large-scale precipitation, small-scale cumulus parameterization, and moist adiabatic adjustment. Three types of convection were simulated: middle-level convection, penetrating convection, and low-level convection by means of a five-level extension of the cumulus convection scheme of ArakawaShubert (J. Atmos. Sci., 31: 674–701, 1974). Calculations of shortwave and long wave radiation fluxes in a model is a complex problem. Hence, a simplified scheme for computing radiative transfer in the troposphere that follows the Katayamaʹs scheme (Technical Report no. 6, Univ. California, 1972) of radiation was used modified to introduce the overlapping of interactive different clouds. The forecast charts obtained here are satisfactory considering that this is a quasi-geostrophic model.