On the use of radon as atmospheric tracer to constrain atmospheric transport

Radon-222 and its progenies in the atmosphere have been widely utilized as powerful tracers to quantify atmospheric processes that include: i) source tracking and transport (within and between troposphere and stratosphere) time scales of air masses, including the stability and vertical movement of air masses; ii) removal rate constants and residence times of aerosols; iii) deposition velocities and washout ratios of aerosols; iv) sources of continental dust in an air mass; v) flux to and exchange between environmental systems of other gaseous species (e.g., CH4, Hg0); and vi) processes of attachment of metal ions to atmospheric aerosols. In addition, radon is increasingly being used as a tool for quantifying stability influences on urban pollutant concentrations. As a rule, radon is especially useful wherever a concentration gradient of this radiotracer is observed, providing a uniquely efficient tool for atmospheric circulation in complex topography conditions. The polar plots methodology is increasingly being used for exploring the sources of atmospheric pollutants. In fact, the use of smart use of wind speed and directionanemological parameters may lead to can be informative because it often leads to the suggestion of source locations and source characteristicszation , such as height of emission above the surfaceon the basis of radon whose behavior is statially and temporally well recognizable. In this work, radon, whose source term is well known, was has been used as a tracer to constrain atmospheric transport of particulate matter and its chemical constituents, together with atmospheric gaseous pollutants, in a coastal site located in north-eastern Italy. Results suggest that under the development of sea-breeze conditions, typical of the warm season, typical of coastal locations such as the measurement sitelike in the present case study, may successfully benefit of this approach in efficiently reconstructing pollutant dynamicsespecially during the summer season, the use of polar plots can be misleading in the absence of independent and well-known tracers.