Testing the performance of state-of-the-art dust emission schemes using DO4Models field data
Within the framework of the Dust Observations for Models (DO4Models) project, the performance of three commonly used dust emission schemes is investigated in this paper using a box model environment. We constrain the model with field data (surface and dust particle properties as well as meteorologic...
| Main Authors: | , , , , , , , |
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| Format: | Article |
| Language: | English |
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Copernicus Publications
2015-02-01
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| Series: | Geoscientific Model Development |
| Online Access: | http://www.geosci-model-dev.net/8/341/2015/gmd-8-341-2015.pdf |
| _version_ | 1811273167766814720 |
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| author | K. Haustein R. Washington J. King G. Wiggs D. S. G. Thomas F. D. Eckardt R. G. Bryant L. Menut |
| author_facet | K. Haustein R. Washington J. King G. Wiggs D. S. G. Thomas F. D. Eckardt R. G. Bryant L. Menut |
| author_sort | K. Haustein |
| collection | DOAJ |
| description | Within the framework of the Dust Observations for Models (DO4Models) project,
the performance of three commonly used dust emission schemes is investigated
in this paper using a box model environment. We constrain the model with
field data (surface and dust particle properties as well as meteorological
parameters) obtained from a dry lake bed with a crusted surface in Botswana
during a 3 month period in 2011. Our box model results suggest that all
schemes fail to reproduce the observed horizontal dust flux. They
overestimate the magnitude of the flux by several orders of magnitude. The
discrepancy is much smaller for the vertical dust emission flux, albeit still
overestimated by up to an order of magnitude. The key parameter for this
mismatch is the surface crusting which limits the availability of erosive
material, even at higher wind speeds. The second-most important parameter is
the soil size distribution. Direct dust entrainment was inferred to be
important for several dust events, which explains the smaller gap between
modelled and measured vertical dust fluxes. We conclude that both features,
crusted surfaces and direct entrainment, need to be incorporated into dust
emission schemes in order to represent the entire spectra of source
processes. We also conclude that soil moisture exerts a key control on the
threshold shear velocity and hence the emission threshold of dust in the
model. In the field, the state of the crust is the controlling mechanism for
dust emission. Although the crust is related to the soil moisture content to
some extent, we are not as yet able to deduce a robust correlation between
state of crust and soil moisture. |
| first_indexed | 2024-04-12T22:54:17Z |
| format | Article |
| id | doaj.art-0a9f1c63319645d4946eee24f0a62c21 |
| institution | Directory Open Access Journal |
| issn | 1991-959X 1991-9603 |
| language | English |
| last_indexed | 2024-04-12T22:54:17Z |
| publishDate | 2015-02-01 |
| publisher | Copernicus Publications |
| record_format | Article |
| series | Geoscientific Model Development |
| spelling | doaj.art-0a9f1c63319645d4946eee24f0a62c212022-12-22T03:13:15ZengCopernicus PublicationsGeoscientific Model Development1991-959X1991-96032015-02-018234136210.5194/gmd-8-341-2015Testing the performance of state-of-the-art dust emission schemes using DO4Models field dataK. Haustein0R. Washington1J. King2G. Wiggs3D. S. G. Thomas4F. D. Eckardt5R. G. Bryant6L. Menut7School of Geography and the Environment, University of Oxford, Oxford, UKSchool of Geography and the Environment, University of Oxford, Oxford, UKSchool of Geography and the Environment, University of Oxford, Oxford, UKSchool of Geography and the Environment, University of Oxford, Oxford, UKSchool of Geography and the Environment, University of Oxford, Oxford, UKUniversity of Cape Town, Environmental and Geographical Science, Cape Town, South AfricaDepartment of Geography, University of Sheffield, Sheffield, UKLaboratoire de Météorologie Dynamique, Ecole Polytechnique, Palaiseau, FranceWithin the framework of the Dust Observations for Models (DO4Models) project, the performance of three commonly used dust emission schemes is investigated in this paper using a box model environment. We constrain the model with field data (surface and dust particle properties as well as meteorological parameters) obtained from a dry lake bed with a crusted surface in Botswana during a 3 month period in 2011. Our box model results suggest that all schemes fail to reproduce the observed horizontal dust flux. They overestimate the magnitude of the flux by several orders of magnitude. The discrepancy is much smaller for the vertical dust emission flux, albeit still overestimated by up to an order of magnitude. The key parameter for this mismatch is the surface crusting which limits the availability of erosive material, even at higher wind speeds. The second-most important parameter is the soil size distribution. Direct dust entrainment was inferred to be important for several dust events, which explains the smaller gap between modelled and measured vertical dust fluxes. We conclude that both features, crusted surfaces and direct entrainment, need to be incorporated into dust emission schemes in order to represent the entire spectra of source processes. We also conclude that soil moisture exerts a key control on the threshold shear velocity and hence the emission threshold of dust in the model. In the field, the state of the crust is the controlling mechanism for dust emission. Although the crust is related to the soil moisture content to some extent, we are not as yet able to deduce a robust correlation between state of crust and soil moisture.http://www.geosci-model-dev.net/8/341/2015/gmd-8-341-2015.pdf |
| spellingShingle | K. Haustein R. Washington J. King G. Wiggs D. S. G. Thomas F. D. Eckardt R. G. Bryant L. Menut Testing the performance of state-of-the-art dust emission schemes using DO4Models field data Geoscientific Model Development |
| title | Testing the performance of state-of-the-art dust emission schemes using DO4Models field data |
| title_full | Testing the performance of state-of-the-art dust emission schemes using DO4Models field data |
| title_fullStr | Testing the performance of state-of-the-art dust emission schemes using DO4Models field data |
| title_full_unstemmed | Testing the performance of state-of-the-art dust emission schemes using DO4Models field data |
| title_short | Testing the performance of state-of-the-art dust emission schemes using DO4Models field data |
| title_sort | testing the performance of state of the art dust emission schemes using do4models field data |
| url | http://www.geosci-model-dev.net/8/341/2015/gmd-8-341-2015.pdf |
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