Rainwater chemistry and atmospheric deposition at Ilha Grande, RJ.

Wet (n = 21) and dry (n = 23) deposition samples were collected front March to September 2002 at the southern coast of IIha Grande. Rainwater pH varied front 4.3 to 6.3 and ionic concentrations (in mu mol L-1) decreased in the order Cl- > Na+ > Mg2+ > SO42- > NO3- similar to NH4+ > K+ similar to H+ > Ca2+. Scavenging of sea-salt aerosols was the major source of Cl-, Na+, Mg2+, and Ca2+. Half of total SO42- was non-sea-salt SO42-. Total composition fluxes of NH4+, NO3-, and non-sea-salt SO42- were respectively 9.3, 17.8, and 16.0 mol ha(-1) month(-1).