title: Factors controlling 7Be and 210Pb atmospheric deposition as revealed by sampling individual rain events in the region of Geneva, Switzerland.
abstract: Bulk atmospheric deposition of 7Be and 210Pb has been measured at Versoix, close to Geneva, Switzerland. Collectors were continuously deployed from November 1997 through November 1998 for periods from 1 to 22 days depending on the frequency of rain. The activities of 7Be and 210Pb integrated over the sampling interval were moderately well correlated with rainfall (r2 of 0.66 and 0.55, respectively; p < 0.001) and well correlated one with the other (r2 of 0.91; p < 0.001). The 7Be/210Pb activity ratio is close to 13.5, except for samples collected in the periods of very low precipitation which have a distinctly lower ratio. A simple model accounting for rainfall, seasonal variations and reload of the local atmosphere after a rain event explains 90% of the variance of 7Be and 210Pb deposition. Concentrations of 210Pb and Ca++ in rain were correlated with transport time of air masses over the continent as indicated by reconstruction of air mass trajectories over three days.
authors.affiliation: Institut F.-A. Forel, Université de Genève, 10 route de Suisse, CH-1290 Versoix, Switzerland.
authors.forename: S
authors.initials: S
authors.lastname: Caillet
authors.forename: P
authors.initials: P
authors.lastname: Arpagaus
authors.forename: F
authors.initials: F
authors.lastname: Monna
authors.forename: J
authors.initials: J
authors.lastname: Dominik
mesh_terms: D000396:Air Pollutants, Radioactive / Q000032:analysis*; D001608:Beryllium / Q000032:analysis*; D007856:Lead Radioisotopes / Q000032:analysis*; D011868:Radioisotopes / Q000032:analysis*; D011891:Rain; D012621:Seasons; D013557:Switzerland
chemical_list: D000396:Air Pollutants, Radioactive; D007856:Lead Radioisotopes; D011868:Radioisotopes; D001608:Beryllium