Study of Periodicity in Some Meteorological Parameters and Solar Indices Over Some Stations in Nigeria

Abstract

Periodicities of the mean monthly values of some meteorological parameters and solar indices over some stations in Nigeria have been examined. We used maximum and minimum temperature, rainfall, relative humidity, evaporation, sunshine duration, solar radiation and windspeed data as climate parameters and sunspot numbers and F10.7cm radio solar flux data as solar activity indicators. The Ikeja, Ilorin and Maiduguri stations were chosen as case studies based on the geographical locations in Nigeria to cover various climatic region from the coastal region in the south to the arid region in the north. The Fourier analysis technique Scargle periodogram was used to study the spectral characteristics of the meteorological variables and solar indices for these three stations. 124months/cycle periodicity, in wind speed, was found for the Ikeja station corresponding to the 125months/cycle of solar activities, showing the influence of solar activities on climate. It was established that solar forcing was very significant over Nigerian climate.

Keywords: periodicity, solar activity, Sun-climate relations