Identificação dos Principais Fatores de Controle do Aporte Atmosférico de Substâncias Inorgânicas no Maciço do itatiaia - RJ

AUTOR(ES)
DATA DE PUBLICAÇÃO

2001

RESUMO

The aim this work was to evaluate the atmospheric deposition of main ions in a remote site of Rio de Janeiro State (RJ). Dry/wet deposition were sampled weekly through automatic precipitation collectors in two sites in the Itatiaia National Park,during a complete seasonal cycle (January 1999 to January 2000). Sampling sites were located at the Itatiaia National Park headquarters (Sede site, at 820 m asl)and at the Itatiaia Plateau (Planalto site, at 2400 m asl). Samples were analyzed for Na+, K+, Mg2+, Ca2+, NH4 +, Cl-, NO3 -, SO4 2-, pH and conductivity. Ion concentrations in Sede were high than in Planalto, except for Cl- (p >0.05). In general, concentrations were low, but wet deposition rates were high, particularly for NH4 +, NO3 - and SO4 2-. NO3 - wet deposition (189 eq ha-1year-1) in Sede was higher than the value reported for Niterói city, RJ. The marine source influenced both sites, but Planalto site presented Cl- excess (non sea salt). Only 3% of the SO4-2 deposition was marine. Volume weighted average pH was 5.35 and 5.00 for Planalto and Sede sites, respectively. Cluster analysis was used to identify outlier events. Multiple linear regression was conducted to identify the main compounds of NO3 - and SO4 2-. Principal component analysis was applied to identify possible sources of rainwater ions. Three factors explained most of the rain concentration variability observed in each site. In the Sede site, these factors represent the acidgas sources, marine source and aerosol sources, while in Planato site the main sources were gas-aerosol, biogenic and marine.

ASSUNTO(S)

deposições atmosféricas geoquímica ambiental itatiaia, maciço do, (rj) brazil análise multivariada biomass burning chuva - análise geociencias multivariate analysis poluição atmosférica queimadas rainwater itatiaia, rj itatiaia, rj chuva atmospheric deposition

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