Atmospheric deposition of 7Be, 210Pb in Xining, a typical city on the Qinghai-Tibet Plateau, China

Abstract

First continuous observations of 7Be and 210Pb monthly total depositional fluxes were performed from December 2014 to November 2017 in Xining, a typical city on the Qinghai-Tibet Plateau, China. The depositional fluxes showed a clear seasonal variation, with peak depositional fluxes in summer for 7Be and in summer or fall for 210Pb, and minimum values in winter for both 7Be and 210Pb. These are ascribed to the seasonal variability in precipitation and the stratosphere-troposphere exchange of atmosphere. The annual depositional fluxes were 1555 Bq m−2 year−1 for 7Be and 284 Bq m−2 year−1 for 210Pb. The annual volume-weighted activities and depositional fluxes of 7Be increased with altitude.