Dynamics of atmospheric turbidity in Nigeria: A geospatial analysis of Linke Turbidity Factor

Atmospheric turbidity plays a critical role in regulating surface solar radiation and has important implications for solar energy utilization, climate variability, and air quality. This study investigates the spatial and temporal dynamics of the Linke Turbidity Factor (TL) across Nigeria using a 13-year (2010–2022) satellite-derived dataset from the Copernicus Atmosphere Monitoring Service (CAMS). Four TL estimation models—Linke, Kasten, Louche, and Grenier—were evaluated to identify the most suitable model for Nigerian atmospheric conditions. Model performance was assessed using statistical metrics including mean bias error (MBE), root mean square error (RMSE), and coefficient of determination (R²). Results indicate that the Linke model consistently outperformed the other models across the six geopolitical zones. Spatial analysis revealed a pronounced southeast–northwest gradient, with the highest mean TL values observed in the South-East (11.20) and the lowest in the South-West (6.27). Mann–Kendall trend analysis showed no statistically significant interannual trends across all zones. Elevated turbidity in southern Nigeria is associated with high atmospheric humidity and anthropogenic emissions, while northern patterns are influenced by Harmattan dust transport. These findings are relevant for solar resource assessment and atmospheric modeling in Nigeria.