Data from: Evolution of turbulent boundary conditions on the surface of large barchan dunes: anomalies in aerodynamic roughness and shear velocity, aeolian thresholds and the role of dune skewness

Louge, Michel Y.; Valance, Alexandre; Porté-Agel, Fernando; Fang, Jiannong; Harnett, Stephen; Chasle, Patrick

Data from: Evolution of turbulent boundary conditions on the surface of large barchan dunes: anomalies in aerodynamic roughness and shear velocity, aeolian thresholds and the role of dune skewness

dc.contributor.author	Louge, Michel Y.
dc.contributor.author	Valance, Alexandre
dc.contributor.author	Porté-Agel, Fernando
dc.contributor.author	Fang, Jiannong
dc.contributor.author	Harnett, Stephen
dc.contributor.author	Chasle, Patrick
dc.date.accessioned	2023-12-13T02:55:52Z
dc.date.available	2023-12-13T02:55:52Z
dc.date.issued	2023-12-12
dc.description.abstract	This collection contains supporting information for M. Y. Louge, A. Valance, J. Fang, S. Harnett, F. Porte-Agel, P. Chasle, Evolution of turbulent boundary conditions on the surface of large barchan dunes: anomalies in aerodynamic roughness and shear velocity, aeolian thresholds and the role of dune skewness, J. Geophys. Res. Earth Surface (2023). It consists of one .xlsx Excel workbook and six .csv worksheets, with contents summarized in the readme.txt file. Wind friction is the engine that erodes sand dunes, relentlessly pushing them over roads, houses and infrastructure. Our records of wind speed on crescent-shaped mobile dunes challenge conventional understanding of this process. Using field measurements and models, we show that the highest friction occurs where the gentle upward dune surface abruptly gives way to a steeper avalanching downward slope. Our data also reveals that the `aerodynamic roughness', a measure of wind friction on sand, contradicts existing models based on historical data for turbulent pipe flow. Because numerical simulations are used to predict flow over landforms that are inaccessible to detailed measurements, we validate them against data on a large dune. Our observations imply that, to achieve greater fidelity, simulations should subdivide the fluid neighborhood of the dune more finely, and revisit how they treat aerodynamic friction on its surface. Although our work involved large desert dunes, we expect these suggestions to apply more broadly to atmospheric, fluvial or submarine landforms that are surrounded by rougher terrain or that feature sudden changes in slope.
dc.description.sponsorship	This collection was made possible by the support of NPRP grants 09-546-2-206 and 6-059-2-023 from the Qatar National Research Fund, and by a Qatar Foundation Research Excellence Award. It was supported in part by the National Science Foundation under Grant No. NSF PHY-1748958, which allowed MYL and AV to attend a program at the Kavli Institute for Theoretical Physics, and by the ISblue project, Interdisciplinary Graduate School for the Blue Planet (ANR-17-EURE-0015) that fostered related discussions on dune modeling. AV acknowledges the support of the French Research National Agency through project ANR-21-CE30-0066.
dc.identifier.doi	https://doi.org/10.7298/6md9-1377
dc.identifier.uri	https://hdl.handle.net/1813/113798
dc.rights	CC0 1.0 Universal	en
dc.rights.uri	http://creativecommons.org/publicdomain/zero/1.0/
dc.subject	desertification
dc.subject	erosion
dc.subject	turbulence
dc.subject	hyper-arid mobile dune
dc.subject	anemometry
dc.title	Data from: Evolution of turbulent boundary conditions on the surface of large barchan dunes: anomalies in aerodynamic roughness and shear velocity, aeolian thresholds and the role of dune skewness
dc.type	dataset