The accession of chloride to the western half of the Australian continent

Abstract

Chloride concentrations in bulk precipitation, collected from 18 sites in remote areas of Australia over 2 years, exhibit a dependence on distance from the coast that is well described by the sum of 2 exponentials. Various processes are discussed in terms of their contribution to the ‘fast’ and ‘slow’ components of this relationship. A map of chloride accession to the western and central areas of the Australian continent is constructed. Maximum deposition occurs at coastal localities (60–70 kg/ha), decreasing to <1 kg/ha in the interior of the continent. Chloride deposition shows a decrease from south (70 kg/ha) to north (<5 kg/ha) of the continent, re˚ecting the greater importance of the subpolar marine airmasses in the supply of ionic species to the Australian continent, and the influence of the continental airmass, low in chloride, on salt deposition in northern Australia.