engleski

Quantifying the influence of local meteorological conditions on air quality in Zagreb using generalized additive models

The research area which defines the influence of meteorological parameters on air quality in Croatia has developed rapidly over the last decade. This paper presents an estimated response of hourly air pollutants (carbon monoxide (CO), sulfur dioxide (SO2), nitrogen dioxide (NO2) and particulate matter (PM10) in Zagreb, Croatia to local scale meteorology in the period 2006-2012. High concentration of these pollutants has a major impact on human health and air quality. The increase of concentration in urban areas is not just a result of sudden emission, but also a result of meteorological conditions which can prevent dispersion or accumulate pollutants at a particular site. A general model is presented, where the logarithm of hourly con centration of an air pollutant is modelled as a sum of non-linear functions of meteorological and several time variables. Time variables have been included to control emissions. The model can be estimated within the framework of generalized additive models (GAMs) and is additive on the logarithmic scale, which results in multiplicative effects on the original scale. Although the model is non-linear, it is simple and easy to interpret. It quantifies how meteorological conditions and emissions influence the level of air pollution. A measure of relative importance of each predictor variable and a statistical evaluation of the model are also presented. Overall, results found that the most important predictor variables are those related to emissions. The aggregate impact of meteorological variables in the model explained 45% of the variance in CO, 14% in SO2, 25% in NO2 and 24% in PM10. This indicates that meteorology, at a local scale, is a relatively strong driver of air quality in Zagreb. Stable atmospheric conditions, in the urban area, go in favor of higher concentration of air pollutants, having a negative impact on human health. The convection processes dominate in unstable conditions and ventilate the boundary layer.

air quality ; gam ; statistical model ;

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