Downscaling dinâmico sobre o Nordeste do Brasil utilizando um modelo climático regional: impacto de diferentes parametrizações na precipitação simulada

Abstract

Studies using regional models in performing dynamic downscaling have been adequate to reproduce the local scale of a region. In this sense, the present study aimed to analyze the sensitivity of rainfall simulation for the year 2009 in the Brazilian Northeast (NEB) using three cumulus parameterization schemes available in RegCM4 model, namely: Anthes Kuo (Kuo) Grell closure Fristish Chappell (GFC), and MIT-Emmanuel (EM). As a condition of initial and boundary large scale model information were used European Centre for Medium-Range Weather Forecasts (ECMWF), specifically the product ERA_interim. Project data Tropical Rainfall Measuring Mission (TRMM) were used for the evaluation of simulated rainfall. Testing and statistical parameters were used as a metric in evaluating simulations. It was found that the model can adequately represent the precipitation compared with data from TRMM. The experiments that came closer to the observations were GFC and EM. The RegCM4 underestimated precipitation in the NEB in early March and overestimating in mid-July. However, we can say that the model is able to reproduce well the climate variability in the region of the NEB, after some adjustments using different parameterizations for the tropics.