Atmospheric dispersion of radon gas and its decay products under stable conditions in arid regions of Australia.

The radon and radon daughter concentration-in-air from natural background are assessed along with the micrometeorology and synoptic weather systems in an arid region of Australia. The radon daughter contribution to population dose is biased towards the frequency of nocturnal inversions. Classical atmospheric models are not applicable during stable atmospheric conditions in inland Australia. An atmospheric Box Model is used along with measured data from tethersonde profiles in predicting radon/radon daughter concentration-in-air. Predicted and measured concentrations are compared for spatial and temporal variations.