title: Influence of precipitation on (7)Be concentrations in air as measured by CTBTO global monitoring system.
abstract: Data collected by the International Monitoring System (IMS) during 2009-2012 were used to study influence of precipitation and relative humidity on changes in (7)Be concentrations in atmosphere. The significant decrease in (7)Be concentrations, corresponding to measurements collected by stations located within Intertropical Convergence Zone (ITCZ) is demonstrated. This effect can be attributed to the process of enhanced wet deposition within the ITCZ. To quantify this effect data collected by IMS stations within ITCZ were thoroughly analyzed. It was found that the atmospheric content of (7)Be strongly decreases under the rain conditions. The rain mediated depletion of (7)Be to half of its before rain value, needs about 62 h in case of light precipitation, while in the case of moderate precipitation about 38 h is needed. In addition the evaluated impact of humidity showed that increase in relative humidity by 20%, for example from 70% ± 5% to 90% ± 5% causes almost a double decrease in beryllium concentration in surface air.
authors.affiliation: International Data Centre, Comprehensive Nuclear-Test-Ban Treaty Organization, PO Box 1200, 1400 Vienna, Austria. Electronic address: jolanta.kusmierczyk-michulec@ctbto.org.
authors.forename: J
authors.initials: J
authors.lastname: Kusmierczyk-Michulec
authors.affiliation: International Data Centre, Comprehensive Nuclear-Test-Ban Treaty Organization, PO Box 1200, 1400 Vienna, Austria.
authors.forename: A
authors.initials: A
authors.lastname: Gheddou
authors.affiliation: International Data Centre, Comprehensive Nuclear-Test-Ban Treaty Organization, PO Box 1200, 1400 Vienna, Austria.
authors.forename: M
authors.initials: M
authors.lastname: Nikkinen
mesh_terms: D000396:Air Pollutants, Radioactive / Q000032:analysis*; D001608:Beryllium / Q000032:analysis*; D011834:Radiation Monitoring; D011868:Radioisotopes / Q000032:analysis*; D011891:Rain; D014329:Tropical Climate
chemical_list: D000396:Air Pollutants, Radioactive; D011868:Radioisotopes; D001608:Beryllium
keywords: Atmospheric aerosols; Beryllium-7; CTBTO global monitoring system; Latitudinal distribution; Scavenging coefficient; Wet deposition