Inter-Connection between Refractivity Gradient Variations and Intertropical Discontinuity over Nigeria

Radio signal transmission is significantly impacted by the troposphere's complexity. As a result, refractivity gradients has been a crucial parameter for path clearance estimation and propagation effects including ducting, super-refraction, and sub-refraction. Through empirical formulations, this study focuses on the correlations that exist between Intertropical Discontinuity (ITD) and Refractivity Gradient. One important factor influencing West African weather patterns is the ITD. Utilising hourly temperature and relative humidity data for the years 2017 and 2018 at two levels (surface and 1000 hpa) gathered from the archives of the European Centre for Medium-Range Forecasts (ECMWF) for twenty meteorological stations in Nigeria, the refractivity gradient values were computed. Using ANOVA method, five regression models (Linear, Cubic, Quadratic, Power and Log) were developed between refractivity gradient and ITD. The linear model (L = B0 + B1RG) have been found to be mostly significant with coefficient of determination ranging between 97% and 99%) across all the regions.