Abstract
Marine aerosol particles were collected in February and March 1993 using an impactor at a remote Pacific island, Minamitorishima (Marcus Island) (24.3°N, 154.0°E). The composition of individual aerosol particles with radii of 0.4 to 2.0 μm was examined with an energy-dispersive X-ray (EDX) analyzer equipped with a transmission electron microscope (TEM). The dominant aerosol type was found to be sea-salt comprising 89 to 98% of the total particles in this radius range in each sample. Sulfur-rich particles and mineral particles were collected with small number fractions (both 3%) of the total particles.
About 5% of the sea-salt particles exhibited weight ratios of Cl/Na less than 1, indicating chlorine deficiencies. However, the modified sea-salt particles were found in a relatively large percentage (about 25%) of sea-salt particles in the sample collected from the air transported from the marine atmosphere close to the Asian continent. These modified sea-salt particles were produced through heterogeneous reactions during long-range transportation under the influence of continental anthropogenic polluted air.
