Variações sazonais de propriedades óticas de aerossóis e identificação de diferentes tipos na Amazônia baseado em dados AERONET

Abstract

Aerosol particles, both from natural origins and from anthropic processes, there are everywhere on the planet. Aerosols influence the climate, as they act in the absorption and scattering of solar radiation, in the formation of clouds, in the cycling of nutrients in ecosystems. They act as condensation nuclei in the formation of raindrops, in the visibility and health of the population. In this sense, aerosol monitoring at different wavelengths becomes useful as additional information is derived in the particle size distribution. The objective of this work was to study the climatology of Optical Depth of Aerosols (AOD 440nm) and Exponent Angstrom α (440nm-870nm). The data were acquired by AERONET (Aerosol Robotic Network) solar photometers installed in sites located in a forest region (Manaus-EMBRAPA) and another in a transition region between forest and pasture (Ji-Paraná). Data of 3 years allowed to evaluate the properties of these aerosols for each site. Aerosol spectral analysis was performed, where the mean AOD value (440nm) for the Manaus-EMBRAPA site was 0.30 (± 0.24) with mean α (440nm-870nm) 1.31 (± 0,37) at the Ji-Paraná site the mean AOD (440nm) was 0.29 (± 0.30) with mean α (440nm-870nm) 1.40 (± 0.30), indicating a higher variability in the Ji-Paraná site. In both sites a higher density of data related to the mixture of aerosols and aerosols of biomass and / or urban burning was identified, with strong influence of local sources of polluted aerosols, besides dust in suspension.