Abstract:
The surface meteorological data recorded at Akure (lat. 07°
17' N, long. 05° 14'E), in South-Western Nigeria are used to
study the seasonal and diurnal variations of surface radio
refractivity, Ns in this 'geographic zone.
The Ns patterns for this geographic location are presented
and these cover the two main seasons of the year: the rainy
and the dry seasons. The percentage contribution of both the
dry and wet terms to the total surface radio refractivity are
also deduced. The seasonal and diurnal variations of No' the
reduced-to-sea level form of Ns' have been compared with that
of surface pressure, P, temperature, T and water vapour
pressure, e. The comparison reveals that the No variations
closely follow that of the water vapour pressure more than any
of the other meteorological parameters.
The monthly mean values of No have been computed for the
rainy and the dry seasons at Akure. The average surface radio
refractivity has been observed to be generally high in the
rainy seaaon, while it reaches the lowest value in January,
during
obtained
the peak of the dry season. The
for Akure is about 378 N-units.
mean value of
iii
Analysis of the experimental results shows that N~ variation
at Akure has maximum value around 1900 hours local time.
