A simple model for air/snow fractionation of aerosol components over the Antarctic Peninsula

A model has been set up to investigate the wet and dry aerosol removal processes which occur in clean air over the Antarctic Peninsula. Input for the model was obtained from bulk chemical analysis and scanning electron microscopy of aerosol and snow samples collected simultaneously at remote sites around the Peninsula. The model predicts that sulphate and sea-salt aerosol will be removed mainly in-cloud by riming of falling snow and ice crystals. Crustal aerosol is principally removed by acting as nuclei for these crystals and by impaction on falling snow. For the largest, locally-generated aerosol dry deposition is indicated as the major removal process. These findings suggest a possible mechanism for the observed air/snow fractionation.