Numerical Simulation of the Airflow Over Barbados

Abstract

A hydrostatic three-dimensional primitive equation model, which includes topography and detailed boundary layer parameterization, has been developed to simulate the lower tropospheric flow overv Barbados on synoptically undisturbed days. Observations indicate that on such days island precipitation shows a distinct nighttime maximum. Using observed data for the initial conditions, the model is fast integrated to a steady-state solution, whereupon a diurnal temperature wave is imposed on the island surface. Three experiments are run: 1) with a realistic representation of the terrain and shape of Barbados, 2) with no terrain but a realistic shape, and 3) with a cross section of Barbados where three-dimensional asymmetries of terrain and coastline are ignored. Results indicate that topography is an important factor in the modification of low-level flow over Barbados, only in a three-dimensional reputation don upward motion develop downwind of the west coast, as observed, and the nocturnal rainfall maximum may be attributed to a moister nighttime low-level environment as compared to the day. Additional meteorological observations are needed to verify certain aspects of the model predictions.