Abstract
Airborne particulate and gaseous sulfur and nitrogen species were measured in the area of the Azores in the Atlantic Ocean. The sampling and analysis protocols are described. Data are presented on the particle number density, non-sea-salt sulfate, sulfur dioxide, N compounds, reduced N compounds, and trace metals. The data indicated that dimethyl sulfide oxidation was the major determinant of fine-particle non-sea-salt sulfate concentrations. It appeared that the sulfate arises from the oxidation of marine dimethyl sulfide emissions, and concentrations of SO sub(2) consistent with such a process were observed. The source of the nitrate was less clear, but could be attributed to the release of precursors from the sea surface and downward transfer from the free troposphere. The mean concentrations of non-sea-salt sulfate, nitrate, ammonium, and nitric acid were 0.40, 0.24, 0.08, and 0.09 mu g/m super(3), respectively.