The effect of climatic global change has altered the
meteorological factor of the ITU model especially in the lower
atmosphere. The refractivity results obtained in an active
tropical region of West Africa need to be reappraised. A model
known as the Tropic model was derived and tested using NOAA
data set. The data set were obtained from Meteorological data
obtained from NOAA (USAF) Climatology center. Radiosonde
data set was at least 39 years between 1973-2012 for six stations
within the North-central of Nigeria. It was observed that the
Tropic model detected tropospheric perturbations caused by the
extensive influence of aerosol influx. This was confirmed by the
hourly refractivity obtained from the ITU model. Hence, the ITU
model and the Tropic model are complementary to each other for
an accurate terrestrial radio links calculation
