| Popis: |
Monthly total rainfall and monthly average temperature data of Nigeria were downloaded from World Bank Data Group site for year 1901 to 2015. Annual total rainfall and annual average temperature were calculated from the data. The decadal average and thirty-year-average of total rainfall and average temperature were also calculated. In order to describe the time-frequency of rainfall and temperature variability, wavelet analysis was employed on time series of the monthly total rainfall, monthly average temperature, annual total rainfall, and annual average temperature using MATLAB software. The constitution of the monthly rainfall and temperature frequency was studied by the global wavelet spectrum. In order to obtain more information, separate bands were modulated. Take for instance, on examining the 8-16-month band by mean of the scales within the range of 8 and 16 months, the periods with low or high variance of the mean monthly and annual temperature were discovered. Variability of the considered climatological parameters was more vivid on thirty-year-average basis than that of annual and decadal basis. Key words: Rainfall data, Temperature data, Wavelet, Climate variability, Climatology |
