Elemental compositions of individual aerosol particles collected over the Southern Ocean: A case study

Marine aerosols have been sampled from the boundary layer over the Southern Ocean. By means of X-ray spectrometry, elemental compositions of individual particles have been studied. The data reveal the occurrence of two chemical processes over the Southern Ocean: (1) modification of sea salts by acidic materials, where Cl− is replaced by SO42− and/or NO3− and (2) fractional recrystallization within evaporating seawater drops followed by shattering. The effects of these phenomena appear to be simultaneously enhanced when there is mass transfer from the free troposphere.