The solubility and deposition of aerosol Fe and other trace elements in the North Atlantic Ocean: Observations from the A16N CLIVAR/CO2 repeat hydrography section

Aerosol and precipitation sampling as part of the 2003 Climate Variability and Predictability (CLIVAR)-CO2 Repeat Hydrography trace element sampling program has produced an aerosol chemistry dataset for a region of the central Atlantic Ocean between 65°N and 5°S. This dataset includes analyses of aerosol particle chemistry as well as Fe and Al solubility (measured using a rapid, flow-through leaching technique). Several factors thought to influence aerosol Fe solubility including chemical weathering and aerosol source are evaluated as well. Air mass back-trajectories were used to characterize the atmospheric regime of each aerosol sample. Aerosol concentrations varied greatly with the highest concentrations observed between 23°N and 8.7°N. Aerosol Fe solubility was 9% ± 5% in seawater and 15% ± 8% in ultrapure deionized water. The concentration of soluble aerosol Fe in seawater was estimated with reasonable accuracy from the concentration of soluble aerosol Fe in deionized water by the relationship logFeSW = (0.85 ± 0.039) logFeDI + log (1 ± 1.2), (r2 = 0.93).