Variations in the concentrations of ionic species in rain events at Pune

Abstract

In the present work, evolutions of the concent rations of major neutralizing agents (Ca²⁺ and NH₄⁺) and acidic species (SO₄^2- and NO₃^-) are computed with Slinn's model using the initial number concentrations of particle size distributions measured at Pune during 1998-1999. Theoretically predicted ionic concentrations are compared with observed ionic concentrations in the sequential samples collected in the rain events at Pune. Also, equivalent ratios [(SO₄^2- + NO₃^-)/(Ca²⁺ + NH₄⁺)] are computed theoretically to study the neutralizing capacity of the atmosphere during precipitation events and compared them with observed ones. The variation of observed equivalent ratios with accumulated rain (mm) indicated that acidic components are always neutralized with neutralizing species.