Internal Mixture of Sea Salt, Silicates, and Excess Sulfate in Marine Aerosols

• Published in: Science (American Association for the Advancement of Science) Vol. 232; no. 4758; pp. 1620 - 1623
• Main Authors: Andreae, Meinrat O., Charlson, Robert J., Bruynseels, Frank, Storms, Hedwig, Van Grieken, Rene, Maenhaut, Willy
• Format: Journal Article
• Language: English
• Published: Washington, DC The American Association for the Advancement of Science 27.06.1986; American Association for the Advancement of Science
• Subjects: Aerosols; Atmosphere; Atmospheric research; Causes of; Chemical composition; Clouds; Composite particles; Contamination; Earth, ocean, space; Environmental aspects; Exact sciences and technology; External geophysics; Gases; Marine; Marine biology; Meteorology; Methods; Minerals; Particle collisions; Particles and aerosols; Pollution; Salts; Seas; Silicates; Sulfates; Origin; Sea salt; Aerosols; Chemical composition; Silicates; Sea air; Coalescence; Droplet; Electron microscopy; Sulfates
• ISSN: 0036-8075; 1095-9203
• DOI: 10.1126/science.232.4758.1620

Individual aerosol particles from the remote marine atmosphere were investigated by scanning electron microscopy and electron microprobe analysis. A large fraction of the silicate mineral component of the aerosol was found to be internally mixed with sea-salt aerosol particles. This observation explains the unexpected similarity in the size distributions of silicates and sea salt that has been observed in remote marine aerosols. Reentrainment of dust particles previously deposited onto the sea surface and collision between aerosol particles can be excluded as possible source mechanisms for these internally mixed aerosols. The internal mixing could be produced by processes within clouds, including droplet coalescence. Cloud processes may also be responsible for the observed enrichment of excess (nonsea-salt) sulfate on sea-salt particles.