Spatial and temporal distribution of MODIS aerosol optical depth over Ghana and comparison with AERONET data

Understanding aerosol distribution in Ghana is vital for protecting health, improving air quality, and enhancing climate resilience. The aerosol distribution over Ghana was examined using estimates of aerosol optical depth (AOD) from the Terra and Aqua satellites' Moderate Resolution Imaging Spectroradiometer (MODIS) for the years 2008–2019. The highest AOD (1.28) was recorded in the year 2016 in the month of February while the least AOD (0.29) was recorded in November 2019. In general, the first quarter of all the years showed higher aerosol loading, which decreased from April to October. Spatial analysis revealed that the AOD loading over the northern belt increased gradually toward the middle and southern belts in January, peaking in February. The slightly high AOD loading of the southern belt in comparison with the northern and middle belts can be explained by population density, urbanization and industrialization in the south. The relatively lower vegetation cover over the northern belt, coupled with the effect of Harmattan, might be the cause of the high loadings. Strong positive correlations of 0.93 and 0.17 low root mean square errors were found between the MODIS satellite AOD data and ground-based AERONET AOD data. Angstrom coefficient analysis revealed the dominance of coarse-mode aerosol presence in Ghana. Offering insight into more than a decade of AOD data, this study aids climate-resilient planning, public health protection, and sustainable environmental management across Ghana.