Characteristics of Atmospheric Transport of Air Pollution for Africa

Abstract

The African continent is an important source of atmospheric constituents including both trace gases and aerosols. Emissions from Africa impact on at least five other continents. These emissions are derived from wind blown dust, biomass burning, biogenic emissions and anthropogenic industrial activities. Atmospheric transport to and from the continent are affected by both the easterly and westerly circulation patterns of the northern and southern hemispheres. Wind blown dust is the most important emission from the Sahel region of Africa. At different times of the year, dust from the Sahara may impact on South America, the Caribbean, the Mediterranean as well as other parts of Europe. Transport over southern Africa is complex and includes recirculation of air over the subcontinent. Transport off the subcontinent may be to the west to the Atlantic Ocean or to the east. Eastward movement of air has been shown to either impact directly on the central Indian Ocean through deposition or reach as far east as Tasmania. Atmospheric transport towards the African continent is extensive and includes emissions that have originated in Asia, North America, Europe and South America.