Spatial heterogeneity of meteorological elements and PM2.5: Joint environmental-meteorological effects on PM2.5 in a Cold City

To quantify the differences in winter thermal environment and air quality and to clarify the main factors influencing PM2.5 concentrations in cold regions, providing references for regional heating supply design and urban planning. In this study, pedestrian-level thermal environmental parameters and PM2.5 concentration were measured and compared across different urban functional zones (UFZs). Additionally, multiple linear regression (MLR), principal component analysis (PCA), and principal component regression (PCR) were employed to analyze the main controlling factors of PM2.5 and air temperature. The findings reveal that regional microclimate temperatures differ significantly, with variations of 2.68–4.31 °C compared to typical MET data. Notably, the Sky View Factor (SVF) emerged as the dominant influence on temperature variations, while PM2.5 concentrations were primarily driven by a combination of ENV (BD, SVF, GnPR) and MET factors (Ta, RH, TSr). The PCR model demonstrated superior predictive accuracy for PM2.5 concentrations (Adjusted R-squared = 0.78) compared to the MLR model (Adjusted R-squared = 0.63). This study not only deepens the understanding of ENV-MET interactions in cold regions, but also provides important recommendations for optimizing urban planning and heating strategies to improve air quality and thermal comfort.