Variation in airborne 134Cs, 137Cs, particulate 131I and 7Be maximum activities at high-altitude European locations after the arrival of Fukushima-labeled air masses

Publication date: October 2016
Source:Journal of Environmental Radioactivity, Volumes 162–163
Author(s): Olivier Masson, Jacqueline Bieringer, Erika Brattich, Axel Dalheimer, Sybille Estier, Ilia Penev, Wolfgang Ringer, Clemens Schlosser, Thomas Steinkopff, Philipp Steinmann, Laura Tositti, Pieter Van Beek, Anne de Vismes-Ott
The Fukushima-labeled air mass arrival, and later the cesium-134 (¹³⁴Cs), cesium-137 (¹³⁷Cs) and particulate iodine-131 (hereafter noted ¹³¹Ip) maximum levels were registered in Europe at different dates depending on the location. Most of those data were obtained at low-altitude sampling areas. Here, we compare the airborne levels registered at different high-altitude European locations (from 850 m to about 3500 m). The integrated ¹³⁷Cs activity concentration was not uniform with regard to the altitude even after a long travel time/distance from Japan. Moreover, the relation of integrated ¹³⁷Cs vs. altitude showed a linear decrease up to an altitude of about 3000 m. A similar trend was noticed for ¹³¹Ip (particulate fraction) while it increased above 3000 m. Comparison with ⁷Be activity concentration showed that, as far as the high altitude location is concerned, the ¹³⁷Cs and ¹³⁴Cs maximum concentrations corresponded to the ⁷Be maximum, suggesting downdraft movements from high tropospheric or stratospheric layers to be responsible for ^137,134Cs increase and peak values. This was also confirmed by high potential vorticity and low relative humidity registered during the peak values.

Graphical abstract

from Radiology via xlomafota13 on Inoreader http://ift.tt/1XHXQ6D
via IFTTT