Temporal investigation of effects of wildfires and aerosols on air pollution changes in Nigeria: a multivariate modelling approach

Tertsea Igbawua

doi:10.61298/rans.2025.3.2.212

Authors

Tertsea Igbawua
[email protected]

Department of Physics, Joseph Sarwuan Tarka University, Makurdi, Nigeria

Keywords:

AOD, Wildfires, Multivariate Regression, Black carbon, Sea salt

Abstract

Understanding the factors that influence Aerosol Optical Depth (AOD) is essential for addressing air pollution and effectively managing air quality. This study examines the impacts of dust aerosol (DU), sea salt (SS), black carbon (BC), and burned areas (BA) on AOD across different Köppen climate zones in Nigeria from 2001 to 2019. Results from a multivariate regression analysis revealed that DU consistently had a strong and significant impact on AOD across all zones (coefficients: between 0.00106 and 0.00779, p < 0.001), indicating the influence of dust from the Sahara Desert and the Bodélé Depression. BC and SS increased AOD in southern and coastal zones, although BC had a negative impact in Aw climate zones. The influence of BC was less consistent, indicating its varied sources, including gas flaring and urban emissions. BA showed mixed effects on AOD across different climate zones. In some zones, BA had a positive but often insignificant impact on AOD, while in others, it exhibited negligible or negative coefficients. This suggests that although biomass burning contributes to aerosol levels, its direct effect on AOD may be mitigated by factors such as precipitation and aerosol interactions during the burning season. SS generally had a significant positive relationship with AOD, especially in coastal and Csb zones. Peaks in SS levels in the mid-2000s and mid-2010s correlated with higher AOD, emphasizing the maritime influence on aerosol levels in these regions. However, the impact of SS on AOD was less pronounced in the BWh zone, reflecting regional differences in aerosol composition and sources. These findings demonstrate the major impact of dust aerosols and the complex contributions of other sources, offering insights for climate-sensitive air quality management in Nigeria.

Dimensions

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