EVALUATION OF REGCM4 RADIATION SCHEMES OVER NORTHEAST BRAZIL
RegCM4, Northeast, modeling, radiation balance, RRTM, CCM3.
Solar radiation and its surface balance (Rn) are extremely important variables for the physical and dynamic processes of the atmosphere, in addition to being the main sources of energy used in the exchange of heat and moisture in vegetation. Dynamic modeling is one of the most powerful research and development tools for climate science, from the operational field to end-of-century climate projections, models play a critical role. Considering that the future of this science requires a better understanding and improvement of these models, knowing whether it is now possible to reliably simulate important variables such as solar radiation and Rn is of paramount importance. This work aims to evaluate which of the radiation schemes present in the Regional Climate Model 4, version 4.7 (RegCM4.7), these being the Community Climate Model 3 (CCM3) and the Rapid Radiation Transfer Model (RRTM), have a better capacity in representing the daily cycle of Rn in the Northeast region of Brazil (NEB). To carry out the research, two hourly simulations were carried out for the year 2014, one using the RRTM and the other using the CCM3 as a radiation scheme. Reanalysis of the global model Hadley Global Environment Model 2 (HadGEM2) was used as contour data. The observed data were obtained by radiometer balance, model CNR4, installed at the Seridó Ecological Station (ESEC-Seridó), in Serra Negra do Norte, a preserved Caatinga region. The evaluation of the results will be given by evaluating the errors and the similarity between the simulations and the observed data, calculating the BIAS error or bias, the root mean square error (RMSE) and the coefficient of agreement of Willmott (d). In a brief analysis of the experiments, it was possible to verify that the radiation schemes diverge a little from each other, but both present the same behavior in relation to the daily cycle of Rn.