Table 5.
Spearman correlations between main air pollutants and climate variables in Madrid metropolitan region during the entire study period (1 January 2020– 1 July 2021).
| Factors | PM2.5 (μg/m3) | PM10 (μg/m3) | O3 (μg/m3) | NO2 (μg/m3) | T (oC) | RH (%) | SI (W/m2) | w (Km/h) |
|---|---|---|---|---|---|---|---|---|
| PM10 (μg/m3) | 0.66** | |||||||
| O3 (μg/m3) | −0.15* | −0.19** | ||||||
| NO2 (μg/m3) | 0.56** | 0.49** | −0.49** | |||||
| T (oC) | 0.15* | 0.05 | 0.73** | −0.37** | ||||
| RH (%) | 0.03 | 0.09 | −0.77** | 0.30** | −0.75** | |||
| SI (W/m2) | −0.18** | −0.12* | 0.75** | −0.61** | 0.81** | −0.71** | ||
| w (Km/h) | −0.36** | −0.29** | 0.29** | −0.39** | 0.32** | −0.38** | 0.24** | |
| PBL (m) | −0.11* | −0.14* | 0.80** | −0.52** | 0.79** | −0.78** | 0.81** | 0.38** |
Note: T (air temperature), RH (air relative humidity), SI (surface solar irradiance), w (wind speed intensity) and PBL (Planetary boundary Layer height), * and ** indicate p < 0.05 and p < 0.01 respectively.