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Vertical distributions of beryllium-7 and lead-210 in the tropospheric and lower stratospheric air

Kownacka L.

Nukleonika

2002

Vol. 47, nr 2

79-82

Vertical distributions of 7Be and 210Pb were observed in the troposphere and lower stratosphere over Poland at several altitudes between 0 and 15 km in the period 1987-1998. These two natural radionuclides are formed from gases in the atmosphere by nuclear processes. They are associated with similar size distributions aerosol particles and are removed from the atmosphere with similar efficiencies by scavenging processes of washout and deposition, however, they have various types of sources in the atmosphere. Vertical profiles of 7Be (cosmogenic origin), characterized by small concentrations near the ground level, increase in the tropospheric levels and at 15 km altitude the concentrations are the highest. The highest concentrations of 210Pb (terrestrial origin) are observed near the ground level, the lowest are below the tropopause, and in the stratosphere the concentration increases slightly. The dependence of the vertical distributions of both radionuclides in the situation of various levels of tropopause are discussed in this work.