Surface renewal as a significant mechanism for dust emission
Wind tunnel experiments of dust emissions from different soil surfaces are carried out to better understand dust emission mechanisms. The effects of surface renewal on aerodynamic entrainment and saltation bombardment are analyzed in detail. It is found that flow conditions, surface particle mot...
| Main Authors: | , , , , |
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| Format: | Article |
| Language: | English |
| Published: |
Copernicus Publications
2016-12-01
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| Series: | Atmospheric Chemistry and Physics |
| Online Access: | https://www.atmos-chem-phys.net/16/15517/2016/acp-16-15517-2016.pdf |
| Summary: | Wind tunnel experiments of dust emissions from different soil surfaces are
carried out to better understand dust emission mechanisms. The effects of
surface renewal on aerodynamic entrainment and saltation bombardment are
analyzed in detail. It is found that flow conditions, surface particle
motions (saltation and creep), soil dust content and ground obstacles all
strongly affect dust emission, causing its rate to vary over orders of
magnitude. Aerodynamic entrainment is highly effective, if dust supply is
unlimited, as in the first 2–3 min of our wind tunnel runs. While
aerodynamic entrainment is suppressed by dust supply limits, surface renewal
through the motion of surface particles appears to be an effective pathway to
remove the supply limit. Surface renewal is also found to be important to the
efficiency of saltation bombardment. We demonstrate that surface renewal is a
significant mechanism affecting dust emission and recommend that this
mechanism be included in future dust models. |
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| ISSN: | 1680-7316 1680-7324 |