Abstract
Aerosol–cloud interactions are important components of the climate system because aerosols can modify cloud optical characteristics and influence atmospheric radiation and precipitation. This study investigated the statistical relationship between aerosol optical depth (AOD) and cloud optical depth (COD) over Kogi East, Nigeria, using monthly Moderate Resolution Imaging Spectroradiometer (MODIS) Aqua observations from January 2019 to December 2025. Area-averaged monthly AOD at 550 nm from the Deep Blue land product and combined cloud optical thickness were obtained from the MODIS/Aqua MYD08_M3 Collection 6.1 product through NASA Giovanni. The matched dataset comprised 84 monthly observations. Descriptive statistics, Pearson product-moment correlation and simple linear regression were applied. AOD ranged from 0.3275 to 1.3678, with a mean of 0.6167 ± 0.2583 and a coefficient of variation of 41.89%. COD ranged from 1.9656 to 20.0880, with a mean of 8.2895 ± 4.5910 and a coefficient of variation of 55.38%. A moderate negative correlation was found between AOD and COD (r = -0.4693, p < 0.001). The fitted model was COD = 13.4322 − 8.3394AOD, with R² = 0.2202. Thus, AOD statistically accounted for about 22.02% of the observed variation in COD, while the remaining variation was associated with other atmospheric and cloud-related factors. The findings establish a quantitative baseline for aerosol–cloud studies over Kogi East, but the statistical association should not be interpreted as proof of a causal aerosol effect because meteorological conditions, aerosol type, cloud regime and satellite retrieval uncertainties can influence both variables.