Seasonal factors influencing in chemical composition of total suspended particles at Pune, India Original Research Article

A study on the chemical characterization of boundary layer aerosols is made based on the collection of TSP and size separated aerosol mass samples at Pune during March 2007–February 2008. This study will be helpful in simulating atmospheric processes responsible for aerosol development over Pune region and understanding its environmental implications related to radiation budget and climate. It is found that major fraction of Ca2+ is locally generated by suspension of soil dust during all the seasons. During pre-monsoon season, coarse Mg2+ is originated from the soil and the sea salt, whereas fine Mg2+ is generated from the local biomass burning. Sizeable amount of SO42− is emitted from local industrial and brick kilnʹs activities. Neutralization of NO3− , generated both from biogenic and anthropogenic sources, is made by NH3 gas generated mainly from anthropogenic sources. The data are further examined in terms of the factors specific to the individual seasons influencing physical and chemical characteristics of the boundary layer aerosols. The specific factors are: (a) Intense local convection during pre-monsoon season; (b) southwesterly wind flow and rainfall activity during monsoon season; and (c) Day time convection and occurrence of low level inversion during post-monsoon and winter seasons.