Saharan Dust Transport Over the North Atlantic Ocean and Mediterranean: An Overview

Abstract

North Africa serves as a huge reservoir of mineral dust. Dust sources are active all year, especially during the summer when they feed strong pulses of dust across the Mediterranean to Europe and the Middle East and across the Atlantic to the Caribbean, Central and North America. Over the North Atlantic in the low and mid latitudes, mineral dust is the major non-sea-salt aerosol component, exceeding the combined mass of all other species. Model estimates yield a dust deposition of 170 Tg yr(-1) to the Atlantic, 25 Tg yr(-1) to the Mediterranean, and 5 Tg yr(-1) to the Caribbean. There is an extremely large seasonal variability in dust deposition and we might expect a comparable variability in consequent ocean effects. However, deposition estimates are highly uncertain because of the paucity of deposition data throughout the region. The greatest uncertainty is associated with the estimation of dry deposition fluxes which in ocean regions close to sources could constitute by far the largest fraction of the total flux. In recent time, dust mobilization may have increased markedly due to human activities; thus a substantial fraction may be regarded as an anthropogenic product.