Modelagem climática regional das componentes do balanço de energia sobre o Bioma Caatinga

Abstract

In recent years, interest in studying the energy balance in the Caatinga has been increasing. There has been a growing number of studies using observed data measured by the eddy covariance (EC) technique and regional modeling for this biome. The objective of this work was to evaluate which of the available radiation schemes in the Regional Climate Model 4 (RegCM4.7) had a better ability to reproduce the net radiation (𝑅𝑛), latent heat flux (λ𝐸), and sensible heat flux (𝐻) in the Caatinga. The study covered the years 2014 and 2015, with two numerical simulations: one using the Rapid Radiation Transfer Model (RRTM) as the radiative transfer model and the other using the Community Climate Model 3 (CCM3). To validate the results, data obtained from a micrometeorological tower equipped with an EC system located in the Ecological Station of Seridó (ESEC-Seridó) in Serra Negra do Norte/RN, a preserved region of Caatinga, were used. The results were evaluated by assessing the errors using BIAS, RMSE, the Willmott concordance coefficient (𝑑), and Pearson's correlation (𝑟). It was possible to verify that the model is capable of representing the daily cycle of 𝑅𝑛 well, with underestimations in the rainy season and overestimations in the dry season. However, it had difficulties in reproducing the mean values and the daily cycle of 𝐻 and λ𝐸, overestimating λ𝐸 and underestimating 𝐻.