1. A comparison of observed and parameterized SO2 dry deposition over a grassy clearing in Duke Forest
- Author
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Myles, LaToya, Heuer, Mark W., Meyers, Tilden P., and Hoyett, Zakiya J.
- Subjects
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SULFUR dioxide & the environment , *ATMOSPHERIC deposition , *TRACE gases , *SOIL chemistry , *FORESTS & forestry , *PLANT canopies - Abstract
Abstract: Deposition of trace gases, such as sulfur dioxide (SO2), can affect plant and soil chemistry in different ecosystems. Measurements over a complex ecosystem, like a forest clearing, are necessary to determine more accurate deposition rates that can be used to improve parameterizations and models. The flux-gradient technique was used to determine SO2 fluxes over grass in a clearing at Duke Forest, North Carolina, USA on 25 June – 2 July 2008. The mean flux was −0.037 ± 0.024 μg m−2 s−1. Dew on the canopy enhanced the uptake of SO2, which increased deposition rates. Deposition velocities (Vd ) fluctuated greatly with a mean of 1.00 ± 0.48 cm s−1. The large variation in Vd was not fully captured by estimates determined from a multilayer model (MLM) and a big-leaf model (BLM). Mean deposition velocities derived from the MLM and BLM were 1.25 ± 0.21 cm s−1 and 0.63 ± 0.12 cm s−1, respectively. The model estimations of Vd in this study were probably affected by uncertainties associated with canopy resistance, particularly with stomatal and non-stomatal processes. [Copyright &y& Elsevier]
- Published
- 2012
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