Characterization of African Dust (PM 2.5) across the Atlantic Ocean during AEROSE 2004

Abstract

An Aerosol and Oceanographic Science Expedition (AEROSE) on the NOAA Ship Ronald H. Brown collected PM 2.5 particles from a Saharan dust storm in March 2004. High levels of PM 2.5 (120 μg m −3) were measured during this Saharan storm over the Atlantic Ocean. The particles were characterized for trace element content, with Al and Fe the most abundant metals. These metals were detected in high concentrations during the Saharan event and exhibited good correlations with PM 2.5, suggesting its soil origin. Other elements (Pb, Ni, Cd) did not correlate with Al and Fe, indicating their anthropogenic origin. Enrichment factor calculation conducted on these trace elements support our findings. Trace element analyses performed on particulate matter from a reference site on land in Puerto Rico (Fajardo), demonstrated similar results to those obtained in the AEROSE expedition, where high concentrations of PM 2.5 and Fe were present concomitantly with Saharan events at this station.