Protection Value of Tropospheric Radio Refractivity over Nigerian Atmosphere

This study enumerates the protection values derivable from refractivity variation of the tropospheric surface in Nigeria. The investigation was conducted in four cities of Nigeria using meteorological data of 2008 procured from the centre for basic space science (cbss), university of Nigeria, (unn), Nsukka. Data were captured from four different stations: Akure, Nsukka, Minna and Sokoto using vantage pro II automatic weather station. Data measurement at half hourly interval for the whole year took place at the ground level, 0 m and 100 m altitude of the troposphere. The results of the analyzed data revealed that at 100 m altitude, Nzukka and Akure experienced better protection at refractivity value of 350 unit than Sokoto and Minna at 250 unit. At the ground level (0) m, refractivity values becomes more distinct with; Nzukka, 500 unit, Akure, 370 unit while Minna and Sokoto shared the same refractivity value of 270 unit. This trend of refractivity variation showed a decreasing order of protection against exposure to damaging effects of the cosmic and out of space radiation as we move from the south towards the northern part of the country.