Silva, Cláudio Moisés Santos eFerreira, Rosaria Rodrigues2021-08-232021-08-232021-05-21FERREIRA, Rosaria Rodrigues. Aspectos ambientais de superfície no bioma Caatinga sob perspectiva observacional e de modelagem regional. 2021. 89f. Tese (Doutorado em Ciências Climáticas) - Centro de Ciências Exatas e da Terra, Universidade Federal do Rio Grande do Norte, Natal, 2021.https://repositorio.ufrn.br/handle/123456789/33234In the tropical region, the Caatinga biome plays a key role in maintaining the balance of surface energy and carbon dioxide (CO2). Thus, the objective of this study was to evaluate how the flows of the components of the energy balance and of the variables that represent the CO2 balance behave in the Caatinga biome, through the use of data measured in situ and with the use of a regional dynamic model. The aim was to evaluate the dexterity and skill of simulations with the Brazilian Developments on the Regional Atmospheric Modeling System (BRAMS) version 5.3 dynamic model, which was coupled to the Joint UK Land Environment Simulator (JULES) version 3.0 surface module. In addition, an assessment was made of the dynamics of CO2 through gross primary productivity (GPP). GPP data were obtained from the remote sensing product MOD17A2H estimated from the Moderate Resolution Imaging Spectroradiometer (MODIS). The observational data used as a validation parameter for the BRAMS model came from an experimental campaign that provided information about the Caatinga, using the eddy covariance method(Eddy Covariance). The results showed that the BRAMS model represented the rainfall regime satisfactorily when compared to the other databases. As for the measured surface parameters, the BRAMS model showed better ability in the dry month for the variables air temperature (Tar), relative air humidity (RH), sensitive heat flow (H), heat flow in the soil (G) and energy balance (Rn) and a bad ability for the latent heat flow (LE). It was also seen that for the dry month, with the exception of the LE flow (correlation r = 0,59), the other simulated variables showed a correlation above 0,80. In the rainy month Tar, LE and Rn had r > 0,90. In addition, it was observed that the G showed the highest deviation and overestimation in relation to the observation, despite having a high correlation (r > 0,80) in the two seasons. In general, after evaluating the ability of simulations with BRAMS in the Caatinga biome, it is suggested that this model can be used as a study tool for the region. However, improvements are necessary, especially in relation to the parameterization of Soil-Vegetation-Atmosphere associated with JULES. Regarding the assessment of CO2 through the GPP, this study showed that the product MOD17A2H represented the monthly variability of the GPP in the Caatinga with a correlation r = 0,65 and R2 = 0,43, however, although the product can describe the annual behavior of the GPP in the Caatinga, improvements are needed to better represent the GPP measured by the Eddy Covariance system.Acesso AbertoBalanço de energiaFloresta tropical sazonalmente secaBRAMSCO2ClimatologiadoctoralThesis