Airborne in situ measurements of vertical profiles of aerosol light scattering, light absorption, and single scattering albedo (ω0) are presented for a number of locations in southern Africa during the dry, biomass burning season. Features of the profiles include haze layers, clean air slots, and marked decreases in light scattering in passing from the boundary layer into the free troposphere. Frequency distributions of ω0 reflect the strong influence of smoke from biomass burning. For example, during a period when heavy smoke was advected into the region from the north, the mean value of ω0 in the boundary layer was 0.81 ¿ 0.02 compared to 0.89 ¿ 0.03 prior to this intrusion. Comparisons of layer aerosol optical depths derived from the in situ measurements with those measured by a Sun photometer aboard the aircraft show excellent agreement.