7Be, 210pb, and 210Po in the surface air from the Arctic to Antarctica

In the present study we have investigated the activity concentrations of Pb-210, Po-210 as well as Be-7 in surface air of the North and South Atlantic (1988-1989), the Arctic Ocean (1991), and along the coastline of Siberia (1994) during succeeding expeditions in the Swedish Polar Research program. During the cruises in the Arctic Ocean during 1991-07-28 to 1991-10-04 the average air concentrations of Be-7 was 0.6 +/- 0.4 mBq/m(3), Pb-210 40 +/- 4 mu Bq/m(3) and Po-210-38 +/- 10 mu Bq/m(3). During the Swedish-Russian Tundra Ecology-94 expedition along the Siberian coastline the average air concentrations of Be-7 and Pb-210 measured during May-July were 11 +/- 3, and 2.4 +/- 0.4 mBq/m(3), and during July-September they were 7.2 +/- 2 and 2.7 +/- 1.1 mBq/m(3) respectively. The results from measurements of the activity concentration of Pb-210 in the air over the Arctic Ocean vary between 75 and 176 mu Bq/m(3). In the air close to land masses, however, the activity concentration of Pb-210 in the air increases to 269-2712 mu Bq/m(3). The activity concentration of Be-7 in the South Atlantic during the cruise down to Antarctica varied between 1.3 and 1.7 with an average of 1.5 +/- 0.8 mBq/m(3). The activity concentration of Pb-210 in the South Atlantic down to Antarctica varied between 6 and 14 mu Bq/m(3). At the Equator the activity concentration recorded in November 1988 was 630 mu Bq/m(3) and in April 1989 it was 260 mu Bq/m(3). The average activity concentration of Pb-210 during the route Gothenburg-Montevideo in 1988 was 290 and on the return Montevideo-Gothenburg it was 230 mu Bq/m(3). The activity concentration of Po-210 in the South Atlantic down to Antarctica varied between 15 and 58 mu Bq/m(3). At the Equator the activity concentration in November 1988 was 170 and in April 1989 it was 70 mu Bq/m(3). The average activity concentration of Po-210 during the route Gothenburg-Montevideo in 1988 was 63 and on the return Montevideo-Gothenburg it was 60 mu Bq/m(3). The average of the activity concentrations in the Antarctic air of Pb-210 was 27 +/- 10 mu Bq/m(3) and of Po-210 it was 12 +/- 7 mu Bq/m(3). All our results were compiled together with other published data, and the global latitudinal distribution of Pb-210 was converted to total annual deposition (Bq/m(2)/a) and fitted to a 4th degree polynomial. By using the global latitudinal distribution of Po-210/Pb-210-activity ratio from our own results the global latitudinal distribution of Po-210 annual deposition was derived. (C) 2014 Elsevier Ltd. All rights reserved.