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List of Abstracts 181P-Observations 2.32 ID:4209 10:30Measurement of atmospheric NH3, NO and NO2 at different environments over IndiaSudhir Kumar Sharma, T.K. Mandal, A. Datta, T. Saud, M. Saxena, R. Gautam, Y.N. Ahammed, D.K. Sukla,R.P. Bhatnagar, A. Mukherjee, S. Nath, B.C. AryaNational Physical Laboratory, New Delhi 110 012, IndiaContact: sudhir@nplindia.ernet.inMixing ratios of atmospheric NH3, NO and NO2 were measured during 2008-10 over three differentmeteorological environments i.e. New Delhi (Delhi), Dibrugarh (Assam) and Thiruvanathapuran (Kerala) tostudy their diurnal, day-to-day variations, source strength and role in acid-base chemistry of atmosphere.NH3, NO and NO2 were measured continuously and precisely using NH3- and NOx-Analyzer, whichoperates on chemiluminescence method having estimation efficiency (>90%) is much higher than thechemical trap method (reproducibility 4.7%). Significant diurnal, day-to-day variations of mixing ratio ofatmospheric NH3, NO, and NO2 were observed during the study period at all the locations. At Delhi, NH3mixing ratio ranges from 1.02 – 46.17 ppb with average mixing ratio of 20.23 ± 9.42 ppb during winterwhereas the mixing ratio ranges from 1.05 – 29.26 ppb with an average value of 17.47 ± 3.25 ppb duringautumn. The mixing ratio of all measured trace gases varying significantly at all the locations might be dueto source strength and meteorological conditions over the seasons. Result reveals that the mixing ratio ofatmospheric NH3 is positively correlated (during winter) with the atmospheric mixing ratio of NO (r^2 =0.79), NO2 (r^2 = 0.91) and negatively correlated with ambient temperature (r^2 = -0.32). Early morningincrease in NO2 mixing ratio may be attributed to conversion of NO to NO2 with the interaction of O3. Thesurface wind direction and wind speed analysis indicates that major possible local sources of atmosphericNH3 are contributed from agricultural activities, road side traffic and industries.P-Observations 2.33 ID:4476 10:30NO2 variations over the ocean observed by MAX-DOASHisahiro Takashima, Hitoshi Irie, Yugo KanayaJapan Agency for Marine-Earth Science and Technology (JAMSTEC)Contact: hisahiro@jamstec.go.jpAtmospheric aerosol and gas measurements by Multi-Axis-Differential Optical Absorption Spectroscopy(MAX-DOAS) on a Japanese research vessel, Kaiyo, were conducted during an ocean cruise over Japan-Guam-Bali-Indian Ocean from February to May 2009. Clear latitudinal variations of NO2 and aerosolextinction were observed by MAX-DOAS with maxima over Japan and Indonesia, as well as by satelliteobservations during the cruise. Relatively higher NO2 concentrations for 0-1 km were sometimes observedover the ocean (~0.25-0.4 ppbv) as compared to the background level (< 0.1 ppbv) partly due to advection ofpolluted air masses. The estimated error in NO2 mixing ratio (errors from the residual in the fitting andadditional change in AOD) during the cruise was as small as ~20% (~0.02 ppbv), even in the lowbackground value case over the ocean. We will also present the other trace gases variations, such as H2O,SO2, HCHO, and CHOCHO during the cruise.P-Observations 2.34 ID:4544 10:30The concentration profile of NO2, SO2 and O3 in Dar es Salaam, Tanzania and its link to atmosphericcorrosionAlbert Mmari 1 , Agnieszka Krata 2 , Johannes Potgieter 3 , René Van Grieken 2 , Sanja Potgieter-Vermaak 21 Dar es Salaam Institute of Technology, Dar es Salaam, Tanzania2 Department of Chemistry, University of Antwerp, Universiteitsplein 1, B-2610 BelgiumiCACGP-IGAC 2010 14 July, 2010