Table 2. Annual Average Global Budgets of 210Pb and 7Be in the Troposphere for 2013 210Pb 7Be Burden, g 209.617 3.27351 Residence time, days 6.48172 22.8865 Sources, g d-1 from stratosphere 0.193321 0.0525679 within troposphere 32.1782 0.132685 Sinks, g d-1 dry deposition 2.79416 0.00584958 wet deposition 29.5597 0.136794 stratiform 22.9547 0.123900 convective 6.60506 0.0128937 radioactive decay 0.0176445 0.0426096 Accumulation Term Initial mass, g 201.990 8.74918 Final mass, g 201.876 8.74868 Difference, g -0.114075 -0.000498772