On the use of the inferential technique to estimate dry deposition of SO2

Inferred dry deposition rates of SO₂ determined using concentrations from a continuously operated chemical monitor are compared to results obtained from weekly averages, a protocol that is currently employed in many dry deposition networks. Results from two years of data were compared to evaluate any seasonal differences in the uncertainty using a weekly sampling protocol. In general, a weekly sampling protocol was found to underestimate the flux by 40% during the growing season when the diurnal cycle of estimated deposition velocity was found to correlate with measured hourly concentrations. For leafless forest conditions, no consistent correlation was found. This results in a 20% underestimate of the flux on an annual basis.