S.K. Sharma, H. Pathak, A. Datta, M. Saxena, T. Saud, T.K. Mandal Proceedings of the International Academy of Ecology and Environmental Sciences ISSN 2220-8860 2011 1(1) 26-35 05/2011 International Academy of Ecology and Environmental Sciences atmospheric NH3 NO NO2 chemiluminescence method diurnal variation Mixing ratios of atmospheric NH3, NO and NO2 were measured during September to October 2008 and September to October 2009 over Delhi to study their variation and possible sources in respect of meteorological condition. Mixing ratio of atmospheric NH3 ranges from 1.05 to 39.26 ppbv with an average value of 17.47+- 3.25 ppbv during 2008. The average mixing ratio of atmospheric NH3 was increased by 7.2% during 2009 over that of 2008. The average mixing ratio of NO2 during 2008 recorded as 4.46+- 1.26 ppbv with ranges between 1.05 to 16.06 ppbv. Significantly higher (p: 0.05) NO2 mixing ratio was recorded during 2008. Early morning increase in NO2 mixing ratio may be attributed to conversion of NO to NO2 with the interaction of O3. Diurnal and day-to-day variations in mixing ratio of atmospheric NH3, NO, NO2 were observed during the study. Result reveals that the mixing ratio of atmospheric NH3 is orrelated with NO (r2= -0.86), NO2 (r2= 0.35), relative humidity (r2= -0.87) and ambient temperature (r2= 0.88). DOI 10.0000/issn-2220-8860-piaees-2011-v1-0003 http://www.iaees.org/publications/journals/piaees/articles/2011-1(1)/Study-on-mixing-ratio-of-atmospheric-ammonia.pdf