The use of cyclic perfluoroalkanes and SF6 in atmospheric dispersion experiments

The study of atmospheric dispersion has become increasingly important over the last 120 years or so. Research in exposure pathways, fate of pollutants, dispersion model evaluation and validation are all reliant on experimental data. The most common atmospheric tracer compounds in use at the present time are the cyclic perfluoroalkanes and sulphur hexafluoride. These compounds are non-toxic, non-reactive and have low atmospheric background concentrations although they are recognized as greenhouse gases. This review discusses their use relative to other tracer species. A brief history of their individual analyses is included. The review then seeks to give a concise description of some representative atmospheric tracer dispersion experiments in terms of range, duration and objectives, and tracers used. Concluding remarks relating to the future use of these species are also presented. Copyright (C) 2011 Royal Meteorological Society