## 4 Results and Discussion  
Descriptive Statistics and Analysis of Interactions Between Air Pollutants and Meteorological Parameters  
Table 1 presents the descriptive statistics of air pollutants and meteorological parameters measured in Sakarya Province from 2021 to 2023. These metrics, including the minimum, maximum, mean, median, standard deviation (SD), and standard error (SE), offer critical insights into the temporal variability of pollutants and their interactions with meteorological conditions. The air pollutant values were measured independently and in absolute concentration, which is widely applied in similar environmental research [30; 31]. Among the air pollutants, NO\({}_{2}\) exhibited the highest mean concentration (32.4 \(\pm\) 11.76 \(\upmu\)g/m\({}^{3}\)), indicating persistent emission sources, such as traffic and industrial activities. Its moderate variability suggests seasonal fluctuations influenced by meteorological conditions like temperature and WS. PM\({}_{10}\) concentrations showed significant variability (31.92 \(\pm\) 16.24 \(\upmu\)g/m\({}^{3}\)), reflecting diverse sources, including traffic, industrial emissions, and natural dust resuspension. The high SD highlights the combined influence of local sources and seasonal factors, such as dry weather or reduced RainF. Carbon monoxide (CO) concentrations were relatively low (0.79 \(\pm\) 0.39 mg/m\({}^{3}\)) and stable throughout the study period, with minimal seasonal variation. This stability suggests localized sources, such as residential heating and vehicular emissions, with limited long-range transport. Nitrogen monoxide (NO) displayed moderate variability (25.8 \(\pm\) 19.35 \(\upmu\)g/m\({}^{3}\)), primarily linked to traffic emissions. Its rapid conversion to NO\({}^{2}\) likely explains its weaker correlation with meteorological parameters compared to other pollutants. Meteorological parameters also exhibited variability, influencing pollutant dynamics. WS averaged 1.58 \(\pm\) 0.59 m/s, significantly affecting the dispersion of pollutants. Higher WS values were associated with lower PM\({}_{10}\) and NO concentrations, particularly during the winter and spring seasons. The mean temperature was 15.94 \(\pm\) 7.02 \({}^{\circ}\)C, ranging from \(-\)1.7 \({}^{\circ}\)C to 29.1 \({}^{\circ}\)C, reflecting seasonal variations. Temperature played a critical role in pollutant dynamics by influencing chemical reactions and local emission sources, such as heating systems during colder months. RH averaged 72.06 \(\pm\) 12.43%, with higher levels enhancing wet deposition and influencing atmospheric chemical transformations. RainF showed significant variability (2.30 \(\pm\) 5.94 mm), contributing to the removal of particulate pollutants like PM\({}_{10}\) through wet deposition, while having limited impact on gaseous pollutants such as NO and CO. The substantial variability in PM\({}_{10}\) concentrations underscores the need for targeted mitigation strategies, particularly during dry seasons when both natural and anthropogenic sources contribute to elevated levels. Similarly, the interplay between NO and NO\({}_{2}\) highlights the critical role of traffic emissions and atmospheric chemical processes, emphasizing the necessity of addressing these pollutants collectively in air quality management. Meteorological factors, particularly WS and RainF, demonstrated the most significant effects on pollutant levels, especially for PM\({}_{10}\). These factors play a vital role in dispersing and removing pollutants from the atmosphere, thereby improving air quality. Conversely, the relative stability of CO concentrations suggests steady emissions from localized sources such as residential heating and vehicular activities, with minimal seasonal influence. Overall, these findings emphasize the intricate interactions between air pollutants and meteorological parameters in Sakarya Province.