Mixing ratio (ppb) Parameter Maximum Minimum Day Night Average Delhi NH3 23.52 3.23 13.55 ± 0.31 12.92 ± 0.46 13.24 ± 0.39 NO 71.61 2.05 35.51 ± 2.38 43.40 ± 2.68 39.29 ± 2.52 NO2 20.22 0.75 13.04 ± 0.37 12.35 ± 0.42 12.69 ± 0.39 Dibrugarh NH3 26.45 1.27 13.48 ± 2.11 13.43 ± 2.45 13.46 ± 2.31 NO 5.02 0.91 2.72 ± 0.12 2.69 ± 0.11 2.70 ± 0.12 NO2 3.65 0.65 1.23 ± 0.06 1.57 ± 0.10 1.41 ± 0.08 Thiruvananthapuram NH3 22.69 1.08 12.11 ± 1.46 13.20 ± 1.56 12.65 ± 1.51 NO 6.51 0.72 3.06 ± 0.23 3.11 ± 0.19 3.09 ± 0.21 NO2 3.02 0.83 1.68 ± 0.14 1.30 ± 0.05 1.49 ± 0.10 ± Standard error (SE) of the mean, P < 0.05

Table 2: Mixing ratio of NH3, NO and NO2 over Delhi, Dibrugarh and Thiruvananthapuram.