Nield, J.M., King, J., Wiggs, G.F.S. et al. (8 more authors) (2013) Estimating aerodynamic roughness over complex surface terrain. Journal of Geophysical Research: Atmospheres , 118 (23). 12948 - 12961. ISSN 2169-897X
Abstract
Surface roughness plays a key role in determining aerodynamic roughness length (zo) and shear velocity, both of which are fundamental for determining wind erosion threshold and potential. While zo can be quantified from wind measurements, large proportions of wind erosion prone surfaces remain too remote for this to be a viable approach. Alternative approaches therefore seek to relate zo to morphological roughness metrics. However, dust-emitting landscapes typically consist of complex small-scale surface roughness patterns and few metrics exist for these surfaces which can be used to predict zo for modeling wind erosion potential. In this study terrestrial laser scanning was used to characterize the roughness of typical dust-emitting surfaces (playa and sandar) where element protrusion heights ranged from 1 to 199 mm, over which vertical wind velocity profiles were collected to enable estimation of zo. Our data suggest that, although a reasonable relationship (R2 > 0.79) is apparent between 3-D roughness density and zo, the spacing of morphological elements is far less powerful in explaining variations in zo than metrics based on surface roughness height (R2 > 0.92). This finding is in juxtaposition to wind erosion models that assume the spacing of larger-scale isolated roughness elements is most important in determining zo. Rather, our data show that any metric based on element protrusion height has a higher likelihood of successfully predicting zo. This finding has important implications for the development of wind erosion and dust emission models that seek to predict the efficiency of aeolian processes in remote terrestrial and planetary environments.
Metadata
Item Type: | Article |
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Authors/Creators: |
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Copyright, Publisher and Additional Information: | © 2013.The Authors. This is an open access article under the terms of the Creative Commons Attribution License, which permits use, distribution and reproduction in any medium, provided the original work is properly cited. |
Keywords: | aerodynamic roughness; surface roughness; terrestrial laser scanning (TLS); wind erosion; spectral analysis; sediment entrainment |
Dates: |
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Institution: | The University of Sheffield |
Academic Units: | The University of Sheffield > Faculty of Social Sciences (Sheffield) > Department of Geography (Sheffield) |
Depositing User: | Symplectic Sheffield |
Date Deposited: | 02 Mar 2015 10:13 |
Last Modified: | 02 Mar 2015 10:13 |
Published Version: | http://dx.doi.org/10.1002/2013JD020632 |
Status: | Published |
Publisher: | American Geophysical Union |
Refereed: | Yes |
Identification Number: | 10.1002/2013JD020632 |
Open Archives Initiative ID (OAI ID): | oai:eprints.whiterose.ac.uk:83804 |