Measurements of atmospheric aerosols from air and snow samples and meteorological measurements taken from a remote site on the Ross Ice Shelf

The chemistry of air and snow at a remote site on the Ross Ice Shelf was conducted to study atmospheric aerosol particulates which are of interest as they may be important regulators of climate and can indicate the relative strengths of natural and man-made sources of aerosol on a global scale. A range of air and snow samples were collected throughout the study period. Aerosol particulates were collected on membrane filters and analysed using atomic absorption spectrometry, ion chromatography and scanning electron microscopy to establish the bulk chemical composition (rock dust, sea salt, sulphate, nitrate, etc) of the aerosol and the physical characteristics of individual particles. The chemical composition was compared with that of fresh snow samples collected immediately after significant snowfalls to understand processes by which aerosol particulates are trapped at the snow surface. Two firn cores down to 4m depth were analysed for major chemical impurities to establish whether a seasonal cycle exists in the impurity content in the air. Ultratrace levels of mercury and toxic organic compounds (such as dioxins and pesticide residues) were investigated. Air filtered for the measurement of airbourne mercury concentrations and surface snow samples were processes to remove and trap mercury for analysis by photoacoustic mercury analysis. Large volumes of snow from a range of depths down to 1.33m was sampled to trap organic compounds of ployurethane foam filters and analysed by mass spectrometry. Meteorological observations (wind speed and direction, air temperature) were carried out at 3 hour intervals during waking hours (09:00 and 00:00) throughout the period of sampling.