Dry deposition of sulphate and nitrate to polypropylene surfaces in a semi-arid area of India

Dry deposition rates of the major ionic species Cl−, NO3−, SO42−, Na+, K+, Ca2+ and Mg2+ were estimated by the surrogate collection technique using polypropylene surfaces. The dry deposition rates of the soil derived cations Ca2+, Na+, K+ and Mg2+ were of the order of 0.4–6.1 mg m−2 d−1. The dry deposition rates of the acidic ions NO3− and SO42− were of similar magnitude, suggesting that they are also soil derived or associated with the soil elements. On a seasonal basis, deposition rates were maximum during the winter followed by summer and minimum during the monsoon.