Aerosols and trace gases characterization over Indo-Gangetic plain in semiarid region

•This study deals with characterization of aerosol and trace gases over Indo Gangetic plain.•TSPM loads are much higher than recommended values set by National Ambient Air Quality in India.•Trace gas concentrations are in the reported range.•Fog has played important role in levels of aerosols and its chemical constituents.•Meteorological conditions play important role in winter season.

This paper deals with measurements of aerosols, their chemical properties and precursor trace gases at Agra in the Indo-Gangetic plain. The average TSPM level is 441.2 μg m−3 and ranges between 60.8 μg m−3 and 1004.6 μg m−3 which are higher than National Ambient Air Quality Standard Values of India. High wind speed from North West direction influences the aerosol load. TSPM load is higher during prefoggy/foggy days and lower during post foggy days. NH4+ concentration is highest followed by NO3−, SO42−, Cl−, K+, Ca2+, Na+, Mg2+ and F−. The high concentration of NH4+ may be probably due to nearby cattle yard, use of fertilizers and biogenic emissions. The concentration of trace gases SO2, NO2, HNO3 and NH3 are 20.8 μg m−3, 26.3 μg m−3, 1.6 μg m−3, 18.6 μg m−3, respectively. The transportation of urban plumes may be responsible for high concentration of SO2 and NO2. HNO3/NO3− ratio is less than unity. There was no correlation between SO2 and SO42−. The ratio of SO42− + NO3− + Cl−/NH4+ are 1.8 and 2.3, respectively indicate that acidifying components are not neutralized only by NH4+ ion.