Trend and variability of aerosol optical depth at UV wavelength (340 nm) over Ilorin AERONET site in the North Central State of Nigeria
| dc.contributor.author | Ibrahim, B. B. | |
| dc.contributor.author | Sharafa, S. B. | |
| dc.contributor.author | Usman, A. | |
| dc.date.accessioned | 2026-04-20T08:54:54Z | |
| dc.date.available | 2026-04-20T08:54:54Z | |
| dc.date.issued | 2020-12-03 | |
| dc.description.abstract | Aerosols are small solid or fluid airborne mass, or particles, that remain suspended in the air and move with the motion of the air within broad limits. The extinction of sunlight reaching the ground by a vertical column of atmosphere due to aerosol is often termed as aerosol optical depth. This research work investigates the trend of Aerosol Optical Depth (AOD) at 340 nm and its variability over 13 years (2002-2014) using AERONET data for Ilorin, Nigeria. Daily and monthly mean, maximum, minimum and range of AOD values and their trends were investigated using regression analysis. The result shows that on annual basis, the minimum value of AOD occurred in the year 2008 with a value of 0.096 in August while the maximum value of AOD occurred in 2006 with a value of 3.878. The highest range of AOD also occurred in the year 2006 with a value of 3.663 in March. On year by year monthly average,the minimum value of AOD occurred in year 2008 with a value of 0.293 in August while the maximum occurred in year 2007 with a value of 1.6747 in January. Year 2008 has the highest value of range with a value of 1.3068. The result further shows that the yearly representation of daily mean, maximum, minimum and range behave similarly in trend with AOD rising from November up to March of the following year. There is a drop in AOD in May until a minimum in August of the year before another rise in the value. A quadratic fit best described the plot of daily mean, maximum, minimum and range of AOD with days of the year. AOD shows positive and negative value of monthly trend throughout the study period. No year with similar monthly trend. This analysis will be useful for air quality assessment studies. | |
| dc.description.sponsorship | Not Applicable | |
| dc.identifier.issn | 2360-8846 | |
| dc.identifier.uri | https://uilspace.unilorin.edu.ng/handle/123456789/17471 | |
| dc.language.iso | en | |
| dc.publisher | School of Science and Technology Education, Federal University of Technology, Minna, Nigeria | |
| dc.subject | Aerosol | |
| dc.subject | Aerosol optical depth | |
| dc.subject | UV | |
| dc.subject | AERONET | |
| dc.subject | Irradiance | |
| dc.title | Trend and variability of aerosol optical depth at UV wavelength (340 nm) over Ilorin AERONET site in the North Central State of Nigeria | |
| dc.type | Article |