Abstract

The climate of the savannah belt of Nigeria is a transition between the equatorial rain forest in the south and the Sahel in the north. It exhibits a well marked wet season and a dry season. The hot dry season begins about the middle of October to about late March, when the North Easterly (NE) winds from the Sahel dominate the climate pattern. Between April and mid October, the climate is dominated by the rain bearing South Westerly (SW) winds from the Atlantic. Consequently, the aerosol loading of the atmosphere vary between these seasons, hence revealing the local contributors to the aerosol load of the atmosphere from one year to another. In this work, aerosols load of the savannah region of Nigeria was studied by graphically analyzing a ten year (2005 – 2014) AERONET Aerosol Optical Depth (AOD) data of Ilorin. The Shaping Constant of the AOD was determined to classify the prevalent aerosol in the region and hence determine the contributors to the aerosol load while the level of aerosol concentration in the region was also determined by the Scaling Constant of the AOD to infer the level of aerosol load in the region. The study revealed that aerosol loading of the atmosphere in the savannah region of Nigeria is characterized by maximum load towards the end of the dry harmattan season especially in the month of March with very large (coarse) particles and minimum aerosol load during the peak of raining season in the month of August with very small (fine) particle size. It was therefore, recommended that Human activities that expose the top soil to wind erosion such as bush burning, open grazing and felling of trees for fuel wood should be controlled through legislation and social work such as tree planting