Climatologia da profundidade ótica e dependência espectral de aerossóis em regiões de floresta e cerrado no Brasil

Abstract

Aerosols play an important role in energy balance of the earth-atmosphere system. aerosol measurements were conducted at four sites, two in forest area (Rio Branco and Ji-Paraná) and two in Cerrado (Cuiaba and Campo Grande) using solar photometer AERONET (Aerosol Robotic Network) global network. 5 years of data allowed to classify properties of aerosols, the weather setting for each site. In this work, the optical depth of aerosol (ODA 440nm) and Angstrom exponent, α (440-870), were used for aerosol analysis. Average AOD (440nm) to Cerrado sites (Cuiaba and Campo Grande) are, respectively, 0.29 (± 0.40), 0.18 (± 0.24), with corresponding average α 1.20 (± 0.39) 1.16 (± 0.36). Average AOD (440nm) for forest sites (Rio Branco and JiParaná) are, respectively, 0.85 (± 0.71), 0.35 (± 0.44), with a corresponding average of 1.38 α (± 0.41) 1.40 (± 0.34). The AOD both Cerrado regions as forest show distinct peaks for dry and rainy season, and are related to seasonal patterns characteristic of aerosols in these regions. The α (440-870) having frequency modes which relate to the major types of aerosols present in both cerrado as forest. A main scenario of aerosols is defined as aerosols originating from biomass burning, with strong influence of local sources of contaminated aerosols. Aeerosol mixture are present significantly while airborne dust has little relevant occurrence in the analyzed data.