Project NUCLIM

Radon (Rn-222) is a naturally occurring radioactive noble gas of predominantly terrestrial origin, with a hal?ife of 3.8 days. This combination of characteristics makes radon an unique tracer. Its half-life is long enough to enable radon to accumulate in the continental boundary layer, while short enough to have a strong vertical gradient and very low radon concentrations in the free troposphere. Furthermore, radon’s half-life is comparable to lifetimes of several short-lived atmospheric pollutants (NOx, SO2, CO, O3), and to timescales of relevant atmospheric processes, making it an ideal atmospheric tracer. Constraining long-term changes in hemispheric mean greenhouse gases (GHGs) requires accurate and current observations of baseline conditions from air masses representative of hemispheric background values - typically air that is well mixed and has been removed from the in?uence of point sources of pollution.

Radon (Rn-222) is a naturally occurring radioactive noble gas of predominantly terrestrial origin, with a hal?ife of 3.8 days. This combination of characteristics makes radon an unique tracer. Its half-life is long enough to enable radon to accumulate in the continental boundary layer, while short enough to have a strong vertical gradient and very low radon concentrations in the free troposphere. Furthermore, radon’s half-life is comparable to lifetimes of several short-lived atmospheric pollutants (NOx, SO2, CO, O3), and to timescales of relevant atmospheric processes, making it an ideal atmospheric tracer. Constraining long-term changes in hemispheric mean greenhouse gases (GHGs) requires accurate and current observations of baseline conditions from air masses representative of hemispheric background values - typically air that is well mixed and has been removed from the in?uence of point sources of pollution.