## 3 Results and Discussion
The often-nonlinear relationships between changes in emissions and changes in concentrations may also explain why lower air pollution may not occur at all locations. In the subsequent section, diurnal variation will be able to reveal more details about changes and differences in air pollution levels since we will use additional data obtained from high-resolution low-cost sensors. Weather conditions can also noticeably contribute to the changes that are seen in pollutant concentrations, and in some cases changes in meteorology can lead to increased air pollution. At the time of this study, meteorological data with 1 h temporal resolution originating from national network station NN1 were available. Meteorological conditions in the interaction with the landscape's physical features are key factors that influence the rate of change, movement, and dispersal of gaseous and particulate matter pollution in the air. Sampling campaign in both BEMS and EMS period was conducted during the heating season (lasting from 15 October until 15 April) in the Republic of Serbia. It is well known that particulate matter concentration may correlate with temperature and relative humidity, and that often it strongly negatively correlates with wind speed [20]. This means that wind speed and temperature are two key factors affecting PM\({}_{2.5}\) and PM\({}_{10}\) concentration distributions emitted from local sources. These two factors will be discussed next. \begin{table}
\begin{tabular}{l l l l l l l l l l l l l l l l} \hline \hline  & \multicolumn{3}{c}{**LN1**} & \multicolumn{3}{c}{**LN2**} & \multicolumn{3}{c}{**LN3**} & \multicolumn{3}{c}{**LN4**} & \multicolumn{3}{c}{**NN1**} \\ \hline
**Period** & BEMS & EMS & EMS\({}^{*}\) & BEMS & EMS\({}^{*}\) & EMS & EMS\({}^{*}\) & BEMS & EMS\({}^{*}\) & EMS\({}^{*}\) & BEMS & EMS\({}^{*}\) & EMS\({}^{*}\) & EMS\({}^{*}\) \\
**Mean** & 30.97 & 43.97 & 32.59 & 23.77 & 24.97 & 17.72 & 39.69 & 28.88 & 252.21 & 29.49 & 20.38 & 36.83 & 49.58 & 41.89 \\
**St.dev.** & 13.24 & 43.56 & 13.84 & **10.31** & 22.30 & 27.62 & 40.17 & 12.49 & 21.85 & 37.64 & 9.83 & 16.89 & 39.95 & 20.30 \\
**Median** & 28.50 & 33.00 & 30.50 & 21.10 & 17.00 & 16.05 & 31.00 & 28.50 & 20.40 & 19.00 & 17.00 & 33.35 & 36.50 & 36.30 \\
**MIN** & 14.00 & 13.00 & 13.00 & 8.70 & 5.00 & 7.30 & 6.00 & 6.00 & 11.70 & 4.00 & 4.00 & 9.70 & 13.20 & 13.20 \\
**MAX** & 62.00 & 243.00 & 66.00 & **44.60** & 122.00 & 40.90 & 219.00 & 51.00 & 122.60 & 209.00 & 42.00 & 85.10 & 231.60 & 88.50 \\ \hline \hline \end{tabular}
\end{table} 
Table 1: Descriptive statistics for PM\({}_{10}\) [\(\mathrm{\SIUnitSymbolMicro m}\)\({}^{3}\)] data collected via the national and local network for air pollution monitoring in Novi Sad for the period of BEMS and EMS campaign in Novi Sad. EMS\({}^{*}\) denotes EMS data with Araklum Desert episode excluded from data. \begin{table}
\begin{tabular}{l l l l l l l l l l l l l l} \hline \hline  & \multicolumn{3}{c}{**LN2**} & \multicolumn{3}{c}{**LN3**} & \multicolumn{3}{c}{**LN4**} & \multicolumn{3}{c}{**NN1**} \\ \hline
**Period** & BEMS & EMS & EMS\({}^{*}\) & BEMS & EMS & EMS\({}^{*}\) & BEMS & EMS\({}^{*}\) & EMS & EMS\({}^{*}\) & BEMS & EMS\({}^{*}\) & EMS & EMS\({}^{*}\) \\
**Mean** & 19.08 & / & 19.95 & 12.09 & 25.22 & 19.44 & 18.71 & 19.95 & 14.77 & 20.95 & 23.95 & 21.42 \\
**St.dev.** & 8.26 & / & 17.52 & 5.19 & 21.25 & 8.51 & 14.85 & 21.06 & 7.63 & 10.08 & 15.44 & 10.65 \\
**Median** & 17.00 & / & 14.00 & 10.95 & 20.35 & 19.00 & 14.80 & 14.00 & 12.40 & 18.30 & 18.50 & 17.60 \\
**MIN** & 7.00 & / & 4.00 & 5.00 & 4.10 & 4.10 & 8.00 & 3.20 & 3.20 & 6.80 & 7.30 & 7.30 \\
**MAX** & 36.00 & / & 97.60 & 28.00 & 99.00 & 35.00 & 84.00 & 99.00 & 33.60 & 50.50 & 86.40 & 48.20 \\ \hline \hline \end{tabular}
\end{table} 
Table 2: Descriptive statistics for PM\({}_{2.5}\) [\(\mathrm{\SIUnitSymbolMicro m}\)\({}^{3}\)] data collected via the national and local network for air pollution monitoring in Novi Sad for the period of BEMS and EMS campaign in Novi Sad.