Analyzing Seasonal Variations in Air Quality with Google Earth Engine: A Case Study of Chattogram, Bangladesh

Air pollution is a serious environmental challenge in Bangladesh, significantly affecting public health and the ecosystem. This study considers analyzing the seasonal fluctuation of air quality in Chattogram by analyzing 13 significant areas near the industrial zone by using Google Earth Engine (GEE) to explore the SENTINEL-5P satellite data for key pollutants, including nitrogen dioxide (NO2), sulfur dioxide (SO2), and carbon monoxide (CO), and QGIS for mapping purposes. The datasets were assessed through four different seasons: winter (December - February), pre-monsoon (March - June), monsoon (July - September), and post-monsoon (October - November). It is found that significant trends over the seasons— where the winter shows the maximum level of pollutant concentrations, i.e., NO2 shows 0.000200 mol/m2 in Patiya and 0.000059 mol/m2 at Bayezid Bostami in the monsoon, and SO2 shows 0.000394526 mol/m2 in Chittagong Port and 0.0000152 mol/m2 in the monsoon period in Bakalia. The variation intensely indicates the changes in concentrations of pollutants over the season and has a strong negative correlation between precipitation, temperature, humidity, and wind velocity. The monsoon season enhances air quality, effectively dispersing rainfall and significantly lowering pollutant levels. Furthermore, the analysis highlights the hotspots or sources of the pollutant all over the year. This study enhances policymakers' understanding of urban air quality by providing actionable strategies to reduce air pollution.