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Estimativa da radiação solar global à superfície usando um modelo estocástico: caso sem nuvens

A radiative transfer model was implemented for a 16-layer stratified atmosphere. The scheme is of a stochastic structure, with a random walk of diffuse photons between transition states until arriving to absorption states within layers, sky or ground. The formalism is associated a first order Markov process. The model exhibits a simple but powerful structure, when compared with other models used for multiple-layered atmospheres. The structure of the model allows the calculation of the planetary reflectance, global radiance in the surface and the absorption in the atmosphere. Transition parameters for each layer are calculated using a delta-SS two-flux approximation. Comparisons with surface measurements and with SBDART code (Santa Barbara DISORT Atmospheric Radiative Transfer), show a good performance of the model when assessing global radiation at ground level for Rayleigh atmospheres as well as for high-loaded aerosol atmospheres during burning season. The precision of the model, in the atmosphere transmittance estimation, makes it important for researchers that act in the area of remote sensing. Main advantages of the model are: simple structure, good accuracy and easy adaptation to an atmosphere composed of an even number of layers.

Solar radiation; irradiance; radiative transfer; stochastic model


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