Atmospheric injections of polonium-210 from the recent volcanic eruptions.

Po-210 and Pb-210 as atmospheric tracers and global atmospheric Pb-210 fallout: a Review

“…There are about 60 of the Earth's 550 historically-active volcanoes erupting each year (excluding those under the ocean floor; Simkin et al, 1994). The concentrations of 210 Po in air were extremely high in weeks and in some cases months before major eruption (Nevissi, 1984;Sheng and Kuroda, 1985;Su and Hu, 2002). Shortly after the eruption stops, over three orders of magnitude decrease in the activity of 210 Po in air even at >1300 km from the eruption site has been reported (Su and Hu, 2002).…”

Atmospheric 210>Po anomaly as a precursor of volcano eruptions

“…We believe it is due to efficient degassing of this highly volatile nuclide followed by long‐range transport from the volcanic edifice at an early stage before violent eruptions take place. In fact, although it was not well understood, high levels of 210 Po/ 210 Pb ratios in fallout samples prior to major volcanic eruptions have been noted elsewhere before, such as the 1980 eruption of Mount St. Helens [ Nevissi , 1984] and the 1982 eruption of El Chichón volcano [ Sheng and Kuroda , 1985].…”

Comparison of 210Po/210Pb activity ratio between aerosol and deposition in the atmospheric boundary layer over the west coast of Japan.

“…Poet et al (1972) and Moore et al (1973Moore et al ( , 1976 concluded that 210Po/ 210Pb ratio does not yield valid aerosol residence time because most of 210Po in the troposphere is not a decay product of 222Rn within the atmo sphere but is of continental surface origin. Fur thermore, Lambert et al (1979Lambert et al ( , 1982 and Sheng and Kuroda (1985) have suggested that the trans port of stratospheric air, which includes 210Po of volcanic origin, into the troposphere increases 210po/210Pb activity ratio in the troposphere . Al though the use of 210Po/210Pb ratios to determine aerosol residence times may not be justified, the variation of the activity ratios between aerosols and depositions will provide useful information about the differences in behavior of the atmo spheric aerosols, which are suspending in the surface air, and the depositions, which are falling through the troposphere.…”