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A detailed physically-based erosion model based on a Large-Eddy Simulation airflow model was used to explore the origin of the dissimilarity observed between the turbulent transport of moment and dust during the Tunisian 2017 field experiment. Simulations support the findings of the experiment, confirming the key role played by the dust emission intermittency to the transport dissimilarity with the momentum, this later one being more continuously absorbed at the surface. Simulations reveal that this dissimilarity diminishes with height as the intermittency of dust emission is progressively lost during the turbulent transport-mixing process. With wind intensity, the dissimilarity diminishes as well, with dust emissions becoming more spatially homogeneous, and thus less intermittent. Our simulations further highlight the additional role played by the fetch length limitation of the erodible plot to the turbulent transport dissimilarity. In presence of a short fetch, the dissimilarity between dust and momentum turbulent transports increases with height as the dust flux footprint integrates dust emission conditions from different surrounding surfaces. This latter process depends on the characteristics of the surrounded surfaces and is expected to be significant in semiarid regions.

For more information on these results see the paper:

Fernandes, R., S. Dupont, and E. Lamaud (2020). Origins of turbulent transport dissimilarity between dust and momentum in semiarid regions, Journal of Geophysical Research - Atmospheres, in press.

In the below attached file, processed data from the LES simulations are also available.

Excel DATA FILE
(Thanks for informing us if you plan to use these data: sylvain.dupont @ inra.fr)