Main Air Pollution Sources Correlated with the Tropospheric No2 Concentration in Romania as Observed by the Tropospheric Monitoring Instrument (Sentinel-5P).

Abstract

Using high-resolution Sentinel-5P satellite data, this study investigates the relationship between the main sources of air pollution and the concentration of NO2 gas in the tropospheric column during the period 2018-2021 in Romania. NO2 data, both raster and time series obtained through remote sensing techniques by the TROPOMI sensor were used for this analysis. Kernel density estimation (KDE) was chosen as a technique to determine the magnitude of the spatial densification of the main sources of NO2 pollution (KDE PS). Hotspot-Coldspot analysis of the NO2 concentration based on Local Indicators of Spatial Association (LISA) was performed using Getis-Ord Gi* statistic. Besides, a correlation and regression analysis was conducted based on a statistical T-test between KDE PS, elevation above sea level, and mean tropospheric NO2 concentration during 2018-2021. The results evidenced that traditional air pollution sources continue to determine the NO2 pollution levels in Romania, these levels aside being also conditioned by the elevation above sea level. We conclude that NO2 pollution can only be reduced in polluted areas if green energy is favored and measures are taken to mitigate polluting traffic in cities.

Keywords

• tropospheric no2
• sentinel-5p
• air pollution sources
• elevation
• romania