On the variability of African dust transport across the Atlantic

We investigate the interannual variability of Saharan dust transport over the Atlantic by using the TOMS/ Nimbus-7 and TOMS/Earth Probe daily aerosol data. We focus on the winter season, and on the area off the North-West African coast (15-30°N, 30-5°W). Previous studies have suggested that the variability of the Saharan dust can be partially explained by the North Atlantic Oscillation. In an alternative approach, we correlate the aerosol data with the positions and the surface pressure values of the two "Centers of Action" in the Atlantic, the Azores High and the Icelandic Low. This approach decouples the two semi-permanent pressure systems, and it reveals that the Icelandic Low does not play a role in the dust concentration for our region of interest. Instead, the position of the Azores High turns out to be the most important factor, with the Azores High latitude yielding the highest correlation (r = 0.48).