Carbon monoxide and nitrogen oxides pollution in Moscow

Major factors (emissions and meteorology) controlling pollution patterns in Moscow are discussed in the context of different types of urban land use. Nitrogen oxide pollution is one of the main air quality problems in the cit y. Power generation is the major source of nitrogen oxides: in 1994, it acc ounted for 63% of the total NOx emissions with transport contributing 30%. CO emissions are produced almost entirely by road transport. An increase in CO levels has been observed since 1990 in line with growing car ownership. Analyses of seasonal and diurnal variations in CO, NO and NO2 concentratio ns are presented. Meteorological conditions during an intense pollution epi sode are analysed in the context of the characteristics of the main sources of pollution. The occurrence of high levels of CO concentrations is associ ated with high pressure systems, surface-based inversions and low wind spee ds. High concentrations of NO2 are caused by fumigation of the surface with pollutants emitted by power plants. The passage of warm weather fronts, th e decay of elevated temperature inversions, and stronger winds are identifi ed as meteorological condition leading to NO2 build-up.