Precipitation chemistry in Amazonia – inorganic components
Mariana
Lino
Gouveia, Instituto de Física da Universidade de São Paulo. Rua do Matão, Travessa R, 187, CEP05508-900, São Paulo, S.P., Brasil, mariana@if.usp.br
(Presenting)
Luciene
Lorandi
Lara, CENA – Lab. de Ecologia Isotópia, CENA/USP, Av. Centenário, 303 13400-970, Piracicaba, SP, Brasil., luciene@cena.usp.br
Theotonio
Pauliquevis, Instituto de Física da Universidade de São Paulo. Rua do Matão, Travessa R, 187, CEP05508-900, São Paulo, S.P., Brasil, theo@if.usp.br
Paulo
Artaxo, Instituto de Física da Universidade de São Paulo. Rua do Matão, Travessa R, 187, CEP05508-900, São Paulo, S.P., Brasil, artaxo@if.usp.br
Rainwater chemical composition was measured from 3 long term wet deposition monitoring stations located in Balbina, Amazonas, Santarém, Pará, and Ouro Preto do Oeste, Rondônia. Ionic components were measured using ion chromatography, and trace elements were determined with ICP-MS. Measured concentrations comprehend sulphate, nitrate, phosphate, organic acids, chlorine, sodium, potassium, magnesium, calcium, DOC (dissolved organic carbon), DIC (dissolved inorganic carbon), among others. Ionic balance was achieved for the 3 sites, with the organic components being responsible for most of the ionic strength. Simultaneous aerosol measurements were performed, with the determination of scavenging ratios for some key trace elements for the three sites. For Balbina and Santarém, the sodium-chlorine ratio is about 0.82, with very significant correlation, meaning that sea-salt contributes to rainwater even in the Central Amazon basin. Significant deposition was observed for potassium, nitrogen compounds and organic acids.