Butler, Harry J. and McTainsh, Grant H. and Hogarth, William L. (2012) Simulations of spatial variability in particle-size emissions during wind erosion events. Earth Surface Processes and Landforms, 37 (13). pp. 1362-1375. ISSN 0197-9337
Abstract
This study simulates how spatial variations in particle-size emissions from a playa affect bulk and size-resolved dust concentration profiles during two contrasting wind erosion events (a small local and a large regional event) in the Channel Country, Lake Eyre Basin, Australia. The regional event had higher dust concentration as a result of stronger frontal winds and higher erodibility across the playa. For each event, two emission scenarios are simulated to determine if measured size-resolved dust concentration profiles can be explained by spatial variability in source area emissions. The first scenario assumes that particle-size emissions from source areas occur at a uniform rate, while the second scenario assumes that particle-size emissions vary between and within source areas. The uniform emission scenario, reproduced measured bulk dust concentration profiles (R2 = 093 regional and R2 = 081 local), however simulated size-resolved dust concentration profiles had poor statistical fits to measured size-resolved profiles for each size class (the highest were R2 = 05 regional and R2 = 03 local). For the differential particle-size emission scenario, the fit to the measured bulk dust concentration profiles is improved (R2 = 097 regional and R2 = 083 local). However, the fit to the size-resolved profiles improved dramatically, with the lowest being R2 = 089 (regional) and R2 = 080 (local). Particle-size emission models should therefore be tested against both bulk and size-resolved dust concentration profiles, since if only bulk dust concentration profiles are used model performance may be over-stated. As the source areas in the first 90 m upwind of the tower were similar for both events, the percentage contributions of each particle-size class to total emissions can be compared. The contribution of each particle-size class was similar even though the wind speed, turbulence and dust concentrations were significantly different; suggesting that the contribution of each particle-size to the total emitted dusts is not related to wind speed and turbulence.
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| Item Type: | Article (Commonwealth Reporting Category C) |
|---|---|
| Refereed: | Yes |
| Item Status: | Live Archive |
| Additional Information: | © 2012 John Wiley & Sons, Ltd. Published online 25 June 2012. Permanent restricted access to published version. |
| Depositing User: | Dr Harry Butler |
| Faculty / Department / School: | Historic - Faculty of Sciences - Department of Maths and Computing |
| Date Deposited: | 12 Sep 2012 11:58 |
| Last Modified: | 14 Oct 2014 22:33 |
| Uncontrolled Keywords: | wind erosion; dust plume; dust sources; dust particle-size |
| Fields of Research : | 04 Earth Sciences > 0406 Physical Geography and Environmental Geoscience > 040607 Surface Processes 05 Environmental Sciences > 0503 Soil Sciences > 050302 Land Capability and Soil Degradation 04 Earth Sciences > 0401 Atmospheric Sciences > 040101 Atmospheric Aerosols |
| Socio-Economic Objective: | D Environment > 96 Environment > 9601 Air Quality > 960199 Air Quality not elsewhere classified D Environment > 96 Environment > 9602 Atmosphere and Weather > 960201 Atmospheric Composition (incl. Greenhouse Gas Inventory) |
| Identification Number or DOI: | 10.1002/esp.3245 |
| URI: | http://eprints.usq.edu.au/id/eprint/21593 |
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