First simultaneous measurements of ozone, CO, and NOy at a high-altitude regional representative site in the central Himalayas

摘要: Simultaneous in situ measurements of ozone, CO, and NOy have been made for the first time at a high altitude site Nainital (29.37°N, 79.45°E, 1958 m above mean sea level) central Himalayas during 2009–2011. CO levels discern slight enhancements daytime, unlike ozone. The diurnal patterns are attributed mainly to dynamical processes including vertical winds boundary layer evolution. Springtime higher ozone (57.5 ± 12.6 ppbv), (215.2 ± 147 (1918 ± 1769.3 parts per trillion by volume (pptv)) regional pollution supplemented with northern Indian biomass burning. However, lower (34.4 ± 18.9 (146.6 ± 71 (1128.6 ± 1035 pptv) summer monsoon shown be associated arrival air mass originated from marine regions. Downward transport altitudes is estimated enhance surface over 6.1–18.8 ppbv. classification based on residence time, variations along trajectory, shows (57 ± 14 (206 ± 125 (1856 ± 1596 continental masses when compared their respective values (28 ± 13 ppbv, 142 ± 47 226 ± 165 background masses. In general, positive interspecies correlations observed which suggest common source regions (except winter). Ozone-CO ozone-NOy slope found comparison those other global sites, clearly indicates incomplete photochemistry greater role this region. CO/NOy value also confirms minimal influence fresh emissions site. Enhancements fire activity period 4–18%, 15–76%, 35–51%, respectively. Despite concentrations Nainital, nearly similar high-altitude sites.