Atmospheric Chemistry and Physics Characteristics, seasonality and sources of carbonaceous and ionic components in the tropical aerosols from Indian region

Abstract. To better characterize the tropical aerosols in Indian region, PM10 samples collected from Chen-nai, India (13.04 ◦ N; 80.17 ◦ E) were analyzed for carbona-ceous and water-soluble ionic components. Concentra-tion ranges of elemental carbon (EC) and organic car-bon (OC) were 2.4–14 µg m−3 (ave. 6.5 µg m−3) and 3.2– 15.6 µg m−3 (ave. 9.1 µg m−3) in winter samples whereas they were 1.1–2.5 µg m−3 (ave. 1.6 µg m−3) and 4.1– 17.6 µg m−3 (ave. 9.7 µg m−3) in summer samples, respec-tively. Concentration of secondary organic carbon (SOC) retrieved from EC-tracer method was 4.6±2.8 µg m−3 in winter and 4.3±2.8 µg m−3 in summer. OC accounted for 38.5±14 % (n = 49) of combined concentrations of carbonaceous and ionic components in PM10. We also found that OC concentrations are generally higher tha