Simulação númerica dos fluxos turbulentos em ambientes do ecossistema caatinga do semiárido brasileiro.

Abstract

This study aims to numerically simulate This work aims to numerically simulate turbulent flows, in particular, the latent and sensible heat fluxes in two contrasting environments of Caatinga vegetation (preserved and degraded). For this purpose, data collected in situ from two micrometeorological towers of the research project entitled “Energy Balance and CO2 fluxes in Environments of the Caatinga Ecosystem in the Brazilian Semiarid” were used. Thus, four periods of the year 2014 were chosen with the following dates: 23 to 31 March, 21 to 29 June, 22 to 30 September, and 23 to 31 December. For the same periods, numerical simulations were performed using the Weather Research & Forecasting (WRF) model for two domains with resolutions of 15 km, 5 km and 1 km. Despite the below-average rainfall, in the analysis of the average latent heat fluxes data measured, it was noted that in the period of June 2014, these values were much higher than in other months due to June being the wettest month of the year. As a result, much of the available energy was used to evapotranspiration. The simulated results showed that the latent heat flux present better results when compared to the data observed in June, both in preserved Caatinga and in degraded Caatinga in the two grids of the model, d01 (15Km), d02 (5Km) and d03 (1Km). As for the sensible heat fluxes, in practically all simulations, the model satisfactorily simulated the observed data.