CHARACTERISTIC AEROSOL OPTICAL DEPTHS DURING THE HARMATTAN SEASON ON SUB-SAHARA AFRICA

Aerosol optical depths were derived from sun photometer measurements i n three narrow bands centered at 500, 675 and 875 nm, taken at Ilorin, Nigeria, located in sub-Saharan Africa. Selected results will be pres ented on the diurnal, seasonal, and interannual variability of spectra l aerosol optical depth for two Harmattan seasons, during 1987-1989. A t 500 nm values between 0.9-1.6 were quite common while the averages w ere between 1-1.2.