Spatial variation of modelled and measured NO, NO2 and O3 concentrations in the polluted urban landscape – relation to meteorology during the Göte-2005 campaign

摘要

Knowledge about temporal and spatial variations of the O and NOrelationship in the urban environment are necessary to assess the exceedanceof air quality standards for NO. Both reliable measurements andvalidated high-resolution air quality models are important to assess theeffect of traffic emission on air quality. In this study, measurements ofNO, NO and O concentrations were performed in Gothenburg, Sweden, during theGöte-2005 campaign in February 2005. The aim was to evaluate thevariation of pollutant concentrations in the urban landscape in relation tourban air quality monitoring stations and wind speed. A brief description ofthe meteorological conditions and the air pollution situation during theGöte-2005 campaign was also given. Furthermore, the Air Pollution Model(TAPM) was used to simulate the NO-regime close to an urban trafficroute and the simulations were compared to the measurements. Importantconclusions were that the pollutant concentrations varied substantially inthe urban landscape and the permanent monitoring stations were not fullyrepresentative for the most polluted environments. As expected, wind speedstrongly influenced measured pollutant concentrations and gradients. Higherwind speeds dilute NO due to stronger dispersion; while at the sametime vertical transport of O is enhanced, which produces NOthrough oxidation of NO. The oxidation effect was predominant at the morepolluted sites, while the dilution effect was more important at the lesspolluted sites. TAPM reproduced the temporal variability in pollutantconcentrations satisfactorily, but was not able to resolve the situation atthe most polluted site, due to the local scale site-specific conditions.