Table 2. Annual Average Global Budgets of 210Pb and 7Be in the Troposphere for 2013 210Pb 7Be Burden, g 234.521 3.50968 Residence time, days 7.24428 25.0733 Sources, g d-1 from stratosphere 0.210571 0.0526385 within troposphere 32.1782 0.132687 Sinks, g d-1 dry deposition 3.30794 0.00933767 wet deposition 29.0611 0.130306 stratiform 20.5649 0.104169 convective 8.49617 0.0261372 radioactive decay 0.0197349 0.0456812 Accumulation Term Initial mass, g 221.152 8.97835 Final mass, g 221.048 8.97796 Difference, g -0.103897 -0.000387192