Analysis of ground‐based 222Rn measurements over Spain: Filling the gap in southwestern Europe. Issue 18 (17th September 2016) - Grossi, C.
Abstract: Harmonized atmospheric 222 Rn observations are required by the scientific community: these data have been lacking in southern Europe. We report on three recently established ground‐based atmospheric 222 Rn monitoring stations in Spain. We characterize the variability of atmospheric 222 Rn concentrations at each of these stations in relation to source strengths, local, and regional atmospheric processes. For the study, measured atmospheric 222 Rn concentrations, estimated 222 Rn fluxes, and regional footprint analysis have been used. In addition, the atmospheric radon monitor operating at each station has been compared to a 222 Rn progeny monitor. Annual means of 222 Rn concentrations at Gredos (GIC3), Delta de l'Ebre (DEC3), and Huelva (UHU) stations were 17.3 ± 2.0 Bq m −3, 5.8 ± 0.8 Bq m −3, and 5.1 ± 0.7 Bq m −3, respectively. The GIC3 station showed high 222 Rn concentration differences during the day and by seasons. The coastal station DEC3 presented background concentrations typical of the region, except when inland 222 Rn‐rich air masses are transported into the deltaic area. The highest 222 Rn concentrations at UHU station were observed when local recirculation facilitates accumulation of 222 Rn from nearby source represented by phosphogypsum piles. Results of the comparison performed between monitors revealed that the performance of the direct radon monitor is not affected by meteorological conditions, whereas the 222 Rn progeny monitor seems to underestimate 222 Rn concentrations under saturated atmospheric conditions. Initial findings indicate that the monitor responses seem to be in agreement for unsaturated atmospheric conditions but a further long‐term comparison study will be needed to confirm this result. Key Points: New ground‐based atmospheric 222 Rn monitoring stations in an underrepresented area of southwestern Europe First comparison of two portable atmospheric 222 Rn monitors: a single‐filter progeny and a direct electrostatic deposition system Direct 222 Rn monitor response is not affected by rain and saturated atmospheric conditions