Temporal variation of atmospheric Be-7 and Pb-210 concentrations and their activity size distributions at Astana, Kazakhstan in Central Asia

摘要

Atmospheric concentrations of Be-7 and Pb-210 obtained by a high-volume air sampler with a cascade impactor were measured from September 2016 to November 2017 in Astana, Kazakhstan. The levels and seasonal variations of atmospheric Be-7 and Pb-210 concentrations were investigated together with their activity size distributions. Typical seasonal variability was observed with higher concentrations of Be-7 occurring in the warm summer and that of Pb-210 towards the cold winter. These trends may be attributed to the increased vertical mixing within the troposphere during the warm summer season and the frequent inversion conditions of the surface layers during the cold winter season.