Analysis of Rainfall and Temperature over Climatic Zones in Nigeria

This study presents the analysis of rainfall and temperature across the climatic zones in Nigeria. Data from ten Global Circulation Models (GCM) regridded to a 1° x 1° spatial resolution was used in this study. Model evaluation was carried out for the models using ground observed data from Nigerian Meteorological Agency (NIMET). Based on the comparison of the models with ground observed data, the ability of the models in simulating the seasonal pattern of precipitation and temperature over each climatic zone and the whole of Nigeria differ to different degrees. Of the four periods, June, July, August (JJA) showed the highest deviation. The seasonal variation of rainfall and temperature across the climatic zones revealed the influence of the Intertropical Discontinuity (ITD) in rainfall variation across each zone with dual rainfall peak over the Guinea. The rainfall distribution showed that Sahel recorded the lowest rainfall while guinea recorded the highest rainfall. Further analysis revealed that rainfall and temperature varied mostly in the sahel. The trend analysis of rainfall and temperature showed increasing trend in rainfall over the whole of Nigeria under RCP45 and RCP85. There was general increase in temperature for all RCPs across the zones and the whole of Nigeria. Further analysis revealed that sahel will experience more dry years in rainfall and more warm years across the zones for temperature. The changes in rainfall and temperature have implications in various sectors of the economy such as agriculture, water resources and health sector. It is well known that research and development complement each other. It is important that further research be carried out particularly in projecting the change in climate at regional scales. This will provide information about the expected change or variation in climate and hence help in the mitigation of the implications of the change in climate.