Use of Pb and Po as Radiotracers for Meteorological Purposes

The paper describes the use of 218Po for evaluation of height of a mixing layer and 210Pb for monitoring of air pollution sources. In the first part a new method of evaluation of the mixing layer height was presented. The novelty of this method consists in the measurement of 218Po concentration in the air. The concentration of 218Po was measured in the surface layer by means of an alpha spectrometer. The remote sensing method (sodar) was chosen as a reference method. The obtained results show that the variation of 218Po concentration in response to the daily changes of the mixing layer of the lower troposphere may become a good tracer to estimate the atmosphere dynamics and transport of pollution by turbulent mixing of the atmospheric air. A statistically significant correlation between the mixing layer height and 218Po concentration in the air was observed and, as a result, a statistical model was developed to determine the mixing layer height. The second part describes the use of 210Pb to determine the air pollution sources. Changes of 210Pb concentrations in the atmosphere were analysed. During the analyses the annual series of 24-hour measurements of the content of 210Pb in particulate matter (PM) and its air concentration were carried out in a specially built air monitoring station in Tarnowskie Gory. The analysis of 24-hour concentrations allowed to assess the average 24-hour background of 210Pb at the level of about 0.4 mBq/m3. Using a stochastic neural network, 24-hour concentrations of 210Pb and 1-hour data on a wind vector a 1-hour concentration of 210Pb were determined. This enabled the assessment of conditional distributions of 210Pb versus 10-degree inflow sectors. (author)