Our knowledge of the physico-chemistry of aerosols in the undisturbed marine environment

A survey is given of our present knowledge of the marine aerosol. On the basis of the aerosol size distribution in undisturbed marine, environments, five different components of the aerosol are discussed: particles with radii larger than 20 μ, sea spray particles, tropospheric background particles, mineral dust particles, and particles with radii smaller than 0.03 μ. Evidence is presented that the troposphere over the oceans is filled with a fairly uniform background aerosol on which the sea spray aerosol is superimposed only within the lowest kilometers above the sea surface. The sea spray component is discussed in detail with respect to size distribution, production, and chemical composition. The various components of the background aerosol seem to be either of continental origin or produced within the atmosphere. New data are presented on the mineral dust component over the Atlantic Ocean that originates from the Sahara.