The monograph describes the mixing ratios of ambient NH3 and other trace gases (NO, NO2, CO, SO2, and HNO3) and its interaction over urban and suburban areas, the Himalayan region and oceanic region of India. The average mixing ratios of ambient NH3, NO, NO2, SO2 and CO were recorded as 19.3 4.4 ppb, 21.1 5.8 ppb, 18.6 4.6 ppb, 1.7 0.5 ppb and 1.8 0.8 ppm, respectively in megacity Delhi. The average mixing ratios of ambient NH3, NO, NO2...