Determinação de frequências dominantes de dados micrometereológicos relacionados a fenômenos naturais em três ecossistemas de Mato Grosso

Abstract

In this study we used micrometeorological variables (temperature, relative humidity, net radiation, sensible heat flux, latent heat flux, photosynthetic active radiation, carbon concentration and water concentration) for three ecosystems: the Amazon transition forest, Vochysia divergens (Cambarazal) and Mixed Pasture (Cerrado), by getting around 110 sets of data a month. Aiming to analyze the data, it was employed a method of time series analysis: Fourier series and the Monte Carlo method for calculating error frequencies and correlate with dominant natural phenomena that influence the ecosystem. With the results obtained by Fourier analysis we can conclude that this research tool can provide important information on the dynamics of microclimatic variables. The dominant periods with higher incidence and greater range of variation in the parameters studied in the time scale were 24, 12, 8 and 6 hours. Higher frequencies appeared dominant, but with lower incidence and variability, especially in periods of 5, 4 and 2 hours. As Net Radiation presented averages with similar behavior to the rest of the variables, we can say that all the peaks are related to solar radiation. The higher frequencies (5-2 hours) may be due to the influence of clouds and aerosols. Although possible differences in cloud cover can be the cause of the greater range of variation in the wetland by the incident radiation, in the studied periods, and less variation in the transition forest. The general conclusion of the work is that in all the three ecosystems studied the incoming solar radiation is the main phenomenon influencing the behavior of all other variables.