Abstract
In this study, Raupach's localized near-field (LNF)theory is combined with appropriate parameterizations ofthe turbulence inside a canopy to investigate how airstability and source configuration influence the fluxfootprint and flux adjustment with fetch in theroughness sublayer. The model equations are solvednumerically. The flux footprint from the LNF predictionis in general more contracted than the prediction basedon the inertial sublayer similarity functions. Invery unstable conditions, the near-field effect causes thefootprint of the elevated canopy source to locatefurther upwind than that of the ground-level source, andthe combined footprint can become negative in situationswhere the two sources are of opposite sign. The fluxfootprint and flux adjustment with fetch in theroughness sublayer are sensitive to source configurationand the parameters specifying wind speed and theLagrangian time scale inside the canopy.
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Lee, X. Fetch and Footprint of Turbulent Fluxes over Vegetative Stands with Elevated Sources. Boundary-Layer Meteorology 107, 561–579 (2003). https://doi.org/10.1023/A:1022819907480
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DOI: https://doi.org/10.1023/A:1022819907480