A Look at Amazon Basin Seasonal Dynamics with the Biophysical ...

COMPARISON AMONG TWO SIMPLE MODELS IN THE CLASSIFICATION OFDAYS AS RESPECT TO CLOUDINESSMoura 1 , R. G., Correia 1 , F. W. S., Mendes 1 , D.1 CPTEC - INPE, Cachoeira Paulista-SP, Brasilrildo@cptec.inpe.brABSTRACTThe Amazon Area, with its gigantic dimensions, a lot of times is studied by means ofsimulations using models. However, it is not easy, for example, to assess the amount ofshort wave radiation that reaches a certain surface, once this radiation depends mainly onthe cloudiness cover, which is difficult to estimate. This work consists of verifying theperformance of simple mathematic formulations to estimate the cloudiness, with theobjective of evaluating the convenience of using those formulations in the classification ofdays as respect to cloudiness. The results showed that in both formulations used in thiswork, it was verified that a large percentage of days was classified as cloudy days, and mostwas classified as partially cloudy, reminding that these results refer to the rainy periods ofthe first LBA campaign. However the largest differences found among the formulations isin the classification of days of clear sky, as one of them classifies, like this, approximatelyhalf of the studied days. Possibly this is related with the different ranges established byeach one of the different formulations.