Air quality within cities is determined not only by the distribution of pollutants but also by the changing meteorological conditions that elevate or reduce the concentration of a given pollutant and induce physicochemical transformations. The aim of this work was to determine the variability and time distribution of sulfur dioxide (SO2) concentration in the urban landscape of Poznań. To achieve this goal, hourly SO2 concentration data from the automatic central city weather station Poznań-Dąbrowskiego for the period 2005‑2016 were compared against the respective hourly meteorological data: air temperature, relative air humidity, atmospheric pressure, wind speed and direction. Relationships between the concentration of SO2 and the various meteorological elements or a set of meteorological conditions across the multi-annual period were established using a Pearson correlation coefficient and multiple element regression analysis. Over the period 2005‑2016, SO2 concentration distribution in Poznań was characterized by a marked seasonal and monthly variation, with SO2 levels more than 3 times higher in winter than in summer. The highest average concentrations of SO2, > 10.5 μg m‑3, were recorded in the winters during winds from the easterly quarter: E, NE, SE. The levels of SO2 significantly depended on meteorological conditions, with positive correlations with atmospheric pressure in winter and a general negative correlation with air temperature, relative humidity and wind speed. For the multi-annual period 2005 to 2016, the annual average concentration of SO2 ranged from 6.5 to 22.7 mg m‑3 during the easterly winter winds, air temperature ranged from ‑7.9oC in 2010 to 1.2oC in 2005, relative air humidity ranged from 82.9% in 2011 to 95.8% in 2009, atmospheric pressure varied from 1001.0 hPa in 2009 to 1022.2 hPa in 2005, and wind speed varied from 1.1 m s‑1 in 2013 to 2.0 m s‑1 in 2016. On the basis of the research it can be observed that the variability of SO2 concentrations in Poznań is affected by the heating season and the location of the city's heat and power plants.

24.2.2019