Biomass burning and nitrogen dioxide pollution over West Africa

Biomass burning is a major source of air pollution across West Africa, yet its contribution to nitrogen dioxide variability is not well understood. Here we use satellite observations from 2019 to 2024 to examine relationships between fire activity and tropospheric nitrogen dioxide across six West African countries. Fire activity shows strong seasonal concentration, while nitrogen dioxide exhibits more moderate variability influenced by both combustion and persistent urban emissions. A strong statistical relationship between fire activity and nitrogen dioxide, with correlation coefficients ranging from 0.68 to 0.97, indicates that seasonal burning contributes to episodic pollution events. Analysis of vertical atmospheric motion at 850 hectopascals shows that dry-season subsidence suppresses dispersion and favors pollutant accumulation. The results demonstrate how emissions and meteorology interact to drive regional pollution variability and identify periods of elevated exposure potential. Improved monitoring is important for air quality management in the region.