Modeled Implications of Global Warming Conditions on Precipitation Totals in Valley and Highland Areas of Nigeria

Global temperature has been increasing causing differences in precipitation response in different physiographic regions as feedback mechanism. The aim of this work is to model the implications of the global warming conditions on precipitation occurrences in the valley and highland areas of Nigeria. Harmonic analysis on the average monthly rainfall observations was performed for 56 years (1961-2016) using the Turbo Pascal for windows programming language in order to implement the computation. This was carried out by fitting a periodic function of sinusoidal character to enhance the determination of the contribution of each harmonic, the amplitude of each harmonic and the time at which each harmonic is maximum. The result of harmonic plots of the grand average monthly rainfall for the valley area of Makurdi and highland area of Jos shows that there exists a similarity in the trend of variations of harmonic series plots of the data as either plots exhibit single rainfall maxima or peak, meaning that rainfall patterns are mono-modal in nature. Modeled result of average monthly rainfall for the valley area of Makurdi shows an increase in rainfall occurrences from the month of January to August but a decrease from September to December, meaning an expectation of more rains immediately after onsets and lesser rains before cessations. The modeled result for the highland area of Jos however shows a decrease in the occurrence of rainfall in the months of January and February but an increase from the month of March to December. The implication is that there will be water deficiency for late crops and aquifer recharge in the valley areas while highland areas will experience delayed onset of agricultural calendar. The study recommends timely release and adherence to weather/climate forecasts.