222Rn concentrations in the atmospheric surface layer over continental Russia from observations in TROICA experiments

Both space and time variations in the Rn-222 concentration in the atmospheric surface layer over continental Russia were analyzed on the basis of data obtained in the Transcontinental Observations into the Chemistry of the Atmosphere (TROICA) experiments. The measurements were taken from a mobile laboratory which was part of a passenger train moving along the Trans-Siberian Railway from Moscow to Vladivostok. The factors that affect the spatial distribution of both daily and seasonal variations in the concentrations of Rn-222 in the surface air were determined: atmospheric vertical stability, geological features of the area under study, and atmospheric precipitation. The influence of temperature inversions on the accumulation of Rn-222 in the atmospheric surface layer was analyzed. The fluxes of Rn-222 from the soil into the atmosphere were estimated for different regions of Russia.