Space-borne air pollution observation from Sentinel-5p Tropomi: relationship between pollutants, geographical and demographic data

This study presents an analysis of the mean atmospheric column nitrogen dioxide (NO2) and carbon monoxide (CO) over the Republic of North Macedonia during a six-month period. Measurements of NO2 and CO obtained from the recently launched Sentinel-5 Precursor spacecraft with TROPOspheric Monitoring Instrument (Sentinel-5P TROPOMI) have been used. The aim of this study was to use relatively high-resolution satellite data for local air quality/air pollution monitoring and to investigate the relation of the pollutants with geographical and demographical data of the study area. For that purpose, along with CO and NO2 data from TROPOMI, population statistics, digital elevation model and vegetation cover have been used for geo-spatial and statistical analyses. The findings show significantly high CO and NO2 values in several parts of the study area, especially high CO values in the Vardar and Polog Valleys, and high NO2 values in the densely populated cities. According to the analyses, there is high positive correlation between the NO2 and the population statistics (r = 0.78; R2 = 0.61) and high negative correlation (r = -0.9; R2 = 0.80) between the altitude and the CO values of the study area. The overall results of this study confirmed the capability of Sentinel-5P TROPOMI data to be used in monitoring the air quality and air pollution over local areas.