Ross, AN (2012) Boundary-layer flow within and above a forest canopy of variable density. Quarterly Journal of the Royal Meteorological Society, 138 (666). 1259 - 1272. ISSN 0035-9009
Abstract
An analytical model is developed for flow within and above a forest canopy with a slowly varying canopy density. Results are compared with existing analytical models for flow over a surface with slowly varying roughness length, and also with numerical simulations. The results show that the analytical solution is successful in capturing the behaviour of the flow for small and slowly changing variations in canopy density. Previous models which only vary the roughness length and neglect changes in displacement height fail to capture the near-surface flow accurately. Including changes in displacement height as well as roughness length changes gives results closer to those obtained with the full canopy model, but even then the flow induced in the canopy leads to significant differences. The analytical model also highlights the sensitivity of the results to the parametrization of the vertical component of the turbulent stress tensor, τ . For shorter wavelength variations in the canopy density, the analytical model breaks down as the more rapid changes in density induce larger flow perturbations which lead to increased flow into and out of the canopy. This kind of idealised analytical study provides important insights into the role of canopy heterogeneities on boundary-layer flow. This is important both for understanding near-surface winds and transport, and also for parametrizing the effects of surface heterogeneities in large-scale weather and climate models.
Metadata
Item Type: | Article |
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Authors/Creators: |
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Copyright, Publisher and Additional Information: | (c) 2012, Wiley-Blackwell. This is an author produced version of a paper published in the Quarterly Journal of the Royal Meteorological Society. Uploaded in accordance with the publisher's self-archiving policy. |
Keywords: | Inhomogeneous canopy density; Variable surface roughness |
Dates: |
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Institution: | The University of Leeds |
Academic Units: | The University of Leeds > Faculty of Environment (Leeds) > School of Earth and Environment (Leeds) |
Depositing User: | Symplectic Publications |
Date Deposited: | 01 Oct 2013 11:48 |
Last Modified: | 15 Sep 2014 03:00 |
Published Version: | http://dx.doi.org/10.1002/qj.989 |
Status: | Published |
Publisher: | Wiley-Blackwell |
Identification Number: | 10.1002/qj.989 |
Open Archives Initiative ID (OAI ID): | oai:eprints.whiterose.ac.uk:76543 |