Atmospheric depositional fluxes of cosmogenic S-35 and Be-7: Implications for the turnover rate of sulfur through the biosphere

作者：Cho Hyung Mi; Hong Young Lim; Kim Guebuem^*

来源：Atmospheric Environment, 2011, 45(25): 4230-4234.

DOI：10.1016/j.atmosenv.2011.05.002

• Sulfur cycle
• S-35
• Be-7
• Pb-210
• Precipitation
• Atmosphere

The wet depositional fluxes of cosmogenic S-35 and Be-7, together with Pb-210, were measured in Seoul, Korea, from April 2004 to April 2005. Approximately half of the annual fluxes occurred in summer, during which about 60% of the precipitations occurred. Our simple box model shows that the theoretical scavenging ratio of S-35/Be-7 to the ground is approximately 0.013, which accounts for the decay for the duration of oxidation and settling. However, we observed similar to 50% higher S-35/Be-7 activity ratios than the theoretical removal ratio over the entire sampling period, with particularly higher (similar to 133%) ratios during November 2004 April 2005. These higher ratios in the winter cannot be explained by sudden incursions of the stratospheric air or longer aerosol residence times, on the basis of Be-7/Pb-210 ratios. We hypothesize that the ratios could occur owing to biomass burning or as plants go dormant and dry during the autumn and winter. Based on this hypothesis, we developed a S-35/Be-7 mass balance model which yields the turnover rate of sulfur in the atmosphere through the biosphere to be 0.015 +/- 0.007 d(-1). Such a rapid sulfur turnover rate should be applied to the prediction model of sulfur inventory changes.

• 出版日期2011-8