Seasonal and long-term variation of ²¹⁰Pb concentration in air, atmospheric deposition rate and total deposition velocity in south Germany

Winkler, R. and Rosner, G. (2000) Seasonal and long-term variation of ²¹⁰Pb concentration in air, atmospheric deposition rate and total deposition velocity in south Germany. Science of the Total Environment, 263(1-3), 57 -68. (doi: 10.1016/S0048-9697(00)00666-5)

Abstract

The activity concentration in air and atmospheric deposition rate of the long-lived radon progeny ²¹⁰Pb has been investigated at Munich-Neuherberg, south Germany, from 1972 (activity concentration) and from 1981 (atmospheric flux) to 1999. For these periods, the continuous measurements yielded an average ²¹⁰Pb activity concentration at ground level of 0.57 mBq m^-3, and an average total ²¹⁰Pb deposition rate to ground of 180 Bq m^-2 year^-1. The average total deposition velocity, which relates the total ²¹⁰Pb deposition rate to the ²¹⁰Pb activity concentration was calculated to be 1.0 cm s^-1. The variation of the data with time was studied by time-series analysis and distinct seasonal patterns were identified. Maximum ²¹⁰Pb activity concentrations in air are observed in the autumn and winter months (October through February) of each year. By contrast, the maximum ²¹⁰Pb deposition rate is observed during summer (June-August), i.e. in the months with the highest amount of rainfall at this site. Like the ²¹⁰Pb deposition rate, the total deposition velocity exhibits a seasonal pattern with maximum values in summer. Due to the long observation period of 18 years, it was possible to observe for the first time a strong positive relationship between ²¹⁰Pb deposition and precipitation, especially for the months May and June and to a smaller extent for several other months. In the long-term, variations of approximately a factor of 2 were observed in the annual average ²¹⁰Pb activity concentrations, the annual deposition sums and the annual average deposition velocities. Since around 1981 ²¹⁰Pb concentrations in air steadily decreased while ²¹⁰Pb depositions increased. As a consequence of these significant trends, the time series of the total deposition velocity exhibits a trend of the data from approximately 0.7 cm s^-1 in 1981 to 1.7 cm s^-1 in 1999.

• Item Type: Articles
• Status: Published
• Refereed: Yes
• Glasgow Author(s) Enlighten ID: Rosner, Professor Guenther
• Authors: Winkler, R., and Rosner, G.
• Subjects: T Technology > TD Environmental technology. Sanitary engineering; Q Science > QD Chemistry
• College/School: College of Science and Engineering > School of Physics and Astronomy
• Journal Name: Science of the Total Environment
• ISSN: 0048-9697