COMPARATIVE ASSESSMENT OF GROUND AND SATELLITE AEROSOL OBSERVATIONS OVER LAGOS-NIGERIA

Sa？etak The performance of ground and satellite measuring sensors or devices in the West Africa climate system is worrisome. These challenges had resulted in the loss of large volume of useful data on notable database e.g. Aerosol Robotic Network (AERONET), Multi-angle Imaging SpectroRadiometer (MISR), Modern-Era Retrospective Analysis for Research and Applications (MERRA) e.t.c. With only about 47% of data available to scientists, it is evident that accurate nowcast or forecast can no longer be guaranteed. The frequent failures of ground measuring devices over West Africa are more systemic than error due to device fabrication. The optical state over Lagos-Nigeria was investigated using the aerosol model. Fourteen years aerosol dataset from MISR and two years aerosol dataset from AERONET were used for the study. The optical state over Lagos is significant due to the massive human population. Lagos is located within the latitude of 6.465 °N and longitude of 3.406 °E. The regression analysis and Mann-Kendall (MK) test show no significant trend and considerable relationship between satellite and ground data. The standard deviations of the optical state via satellite and ground observations are 0.131 and 0.233, respectively. The average optical state predictability of the satellite and ground observation was 14.2% and 53.1%, respectively. The atmospheric constants in Lagos are: a 1 = 1.175, a 2 = 0.8227, n 1 = 0.2926, n 2 = 0.3573, and a = b = π/2