Detailed Assessment of the Effects of Meteorological Conditions on PM10Concentrations in the Northeastern Part of the Czech Republic

This article assessed the links between PM(10)pollution and meteorological conditions over the Czech-Polish border area at the Trinec-Kosmos and Vernovice sites often burdened with high air pollution covering the years 2016-2019. For this purpose, the results of the measurements of special systems (ceilometers) that monitor the atmospheric boundary layer were used in the analysis. Meteorological conditions, including the mixing layer height (MLH), undoubtedly influence the air pollution level. Combinations of meteorological conditions and their influence on PM(10)concentrations also vary, depending on the pollution sources of a certain area and the geographical conditions of the monitoring site. Gen1erally, the worst dispersion conditions for the PM(10)air pollution level occur at low air temperatures, low wind speed, and low height of the mixing layer along with a wind direction from areas with a higher accumulation of pollution sources. The average PM(10)concentrations at temperatures below 1 degrees C reach the highest values on the occurrence of a mixing layer height of up to 400 m at both sites. The influence of a rising height of the mixing layer at temperatures below 1 degrees C on the average PM(10)concentrations at Trinec-Kosmos site is not as significant as in the case of Vernovice, where a difference of several tens of mu g center dot m(-3)in the average PM(10)concentrations was observed between levels of up to 200 m and levels of 200-300 m. The average PM(10)hourly concentrations at Trinec-Kosmos were the highest at wind speeds of up to 0.5 m center dot s(-1), at MLH levels of up to almost 600 m; at Vernovice, the influence of wind speeds of up to 2 m center dot s(-1)was detected. Despite the fact that the most frequent PM(10)contributions come to the Trinec-Kosmos site from the SE direction, the average maximum concentration contributions come from the W-N sectors at low wind speeds and MLHs of up to 400 m. In Vernovice, regardless of the prevailing SW wind direction, sources in the NE-E sector from the site have a crucial influence on the air pollution level caused by PM10.