Geochemical fractionation during mass transfer from sea to air by breaking bubbles

Physico-chemical hydrodynamics of bubble-breaking and surface chemistry together will explain many of the anomalous ion-ratios reported for the marine component of atmospheric aerosols and precipitation.The “enrichment” of phosphate in bubble-produced aerosol from a solution containing radioactive P-32 and Na-22 is defined asE = (P-32/Na-22) aerosol/(P-32/Na-22) solution – 1and is positive for all solutions studied. Phosphate is always present in excess in drops from breaking bubbles. For jet drops, E lies between 0.01 and 10; for drops from film caps which have drained and lost nearly all of their bulk solution, E may rise as high as 1000. Phosphate is preferred to chloride as a counter-ion below positively-charged surfactants, and also seems to be bound to peptide-like uncharged materials.The mechanism is not specific for phosphate, but can be invoked to explain the enrichment of any constituent of marine aerosol whose absolute ionic potential is greater than Na+ or Cl-.