Contribution of Sentinel-5P satellite images for the monitoring of aerosol particles in Benin

Abstract

This study aims to map aerosol particles on Beninese territory from Sentinel-5P satellite images. In the absence of a ground-based measurement network, remote sensing becomes the tool for monitoring and predicting air quality to understand the environmental and health risks of aerosol particle emissions into the atmosphere. A total of 36 images of the Sentinel-5P's TROPOMI (TROPO spheric Monitoring Instrument) sensor of the year 2019 were acquired. The methodology adopted and based on the calculation of the aerosol index made it possible to extract the aerosol cards. Thus, the results obtained prove the usefulness of Sentinel-5P images in detecting aerosol particles. The maximum value of the aerosol index was recorded in February (AI = 1.859) for a minimum value of -3.3687, recorded in August. The wet June-July-August period impacts on the distribution of these air pollutants related to the leaching process unlike the dry period February-March-April during which concentrations are maximum. Periods of high concentrations of particles thus present a high risk of respiratory diseases, especially in the northern part of Benin. Measures must therefore be taken to limit respiratory risks during these months of drought through a geographical early warning system by combining ground-based measurements with satellite data for real-time monitoring.