bertii rolf ragnar persson (1 Ergebnisse)

Taschenbuch. Zustand: Neu. Neuware -The aim to review the global distribution and temporal changes of 7Be, 210Pb, and 210Po in the surface air is to analyse and model the data revealed during the Swedish polar expeditions with others published results. The relation of air concentrations and depositions of 7Be, 210Pb, and 210Po was modelled to the time period of data collection, latitude, longitude, and height above sea level. The latitudinal distribution of 7Be air concentration has a minimum at the equator and decreasing at extremely high and low latitudes. The latitudinal distribution of the 210Pb activity concentration in air and annual deposition showed a maximum at about 45 °N, with a steady decrease towards higher and lower latitudes. There seems to be a steady increase of the activity concentration of 210Pb in the surface air with time which might occur due to global warming. A partial least squares regression modelling indicated a decrease of the predicted 7Be/210Pb activity ratio with time in the atmosphere, which confirms the 210Pb activity increase. The 210Po/210Pb activity ratios seem to be widely spread along the latitudes with a slight tendency to increase towards the northern latitudes.Books on Demand GmbH, Überseering 33, 22297 Hamburg 84 pp. Englisch.