Long-range transport of continental radon in subantarctic and antarctic areas

• Published in: Tellus B: Chemical and Physical Meteorology
• Main Authors: Polian, Georges, Lambert, Gerard, Ardouin, Benedicte, Jegou, Alain
• Other Authors: Centre des Faibles Radioactivités, Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Centre National de la Recherche Scientifique (CNRS)
• Format: Article in Journal/Newspaper
• Language: English
• Published: HAL CCSD 1986
• Subjects: [SDU.OCEAN]Sciences of the Universe [physics]/Ocean; Atmosphere; [SDU.ENVI]Sciences of the Universe [physics]/Continental interfaces; environment; Antarctic; Indian; The Antarctic; Antarc*
• Online Access: https://hal.science/hal-03541045; https://hal.science/hal-03541045/document; https://hal.science/hal-03541045/file/Long%20range%20transport%20of%20continental%20radon%20in%20subantarctic%20and%20antarctic%20areas.pdf; https://doi.org/10.3402/tellusb.v38i3-4.15126

International audience Gaseous Rn-222, a daughter product of U-238, is injected into the atmosphere from the surface of continents. Its atmospheric cycle is particularly simple since it disappears only by radioactive decay (half-life 3.8 days). Radon measurements obtained over more than 15 years in remote stations in Antarctic and Subantarctic areas generally give concentrations as low as 0. I to 2 pCi.m-'. However, we have shown the existence of sharp increases of concentrations reaching 3 to 30 pCi'rn-' called "radonic storms". Owing to the negligible degassing of radon from the sea surface, such peaks are accounted for by long-range transport from remote continents (mainly South Africa) over Southern Indian and Antarctic oceans, with transit times ranging from 1.5 to 7 days and very low dilution factors of the order of 3 to 7. This airmass transport is related to warm sectors of cyclonic systems passing over South Africa and around the Antarctic continent.