The Study of Altitudinal Refractivity and Refractivity Gradient Variations by Weather Parameters in Some Selected Locations in Nigeria

Weather parameters such as pressure, temperature and humidity significantly affect the altitudinal refractivity and refractivity gradients which in return impact the propagation of the radio wave. The alteration in these parameters changes the atmospheric refractive index. Radio refractivity expresses the degree at which a radio signal bends when it travels through the atmosphere. This study examines weather parameters effects on the altitudinal refractivity and refractivity in some selected locations in Nigeria using existing mathematical models relating them with some meteorological parameters from the ground surface to altitude of 12 Km. Higher Refractivity at the ground surface was observed than at elevated altitudes. Decrease in the weather parameters was continuously noticed up to the tropopause as the altitude was increasing. Refractivity gradient was observed to be greater than -40 N up to a height of 4 Km and less than -40 N above 4 Km. The weather parameters have great influence on the altitudinal refractivity and refractivity in the examined locations.