Comparison of Several Techniques for Determining Dry Deposition Flux

摘要

Over the period from 1/22/81 through 5/4/82, measurements were conducted to permit comparison of several techniques for determining dry deposition flux of nitrates and sulfates. Direct flux estimates were made by using actual leaf surfaces and foliar wash and by exposing and washing three surrogate surfaces: bucket, petri dish, and cellulose filter. Indirect flux estimates were made using SSI high volume sampling along with meteorological measurements. The time scale for the direct methods was nominally one month. The indirect method used 24-hour particulate sampling and three-hour meteorological observations to calculate average flux values for the exposure periods of the direct methods. This permitted comparison of direct and indirect methods on a similar time scale.