Alignment of atmospheric mineral dust due to electric field
Optical polarimetry observations on La Palma, Canary Islands, during a Saharan dust episode show dichroic extinction indicating the presence of vertically aligned particles in the atmosphere. Modelling of the extinction together with particle orientation indicates that the alignment could have been...
| Main Authors: | , , , , |
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| Format: | Article |
| Language: | English |
| Published: |
Copernicus Publications
2007-12-01
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| Series: | Atmospheric Chemistry and Physics |
| Online Access: | http://www.atmos-chem-phys.net/7/6161/2007/acp-7-6161-2007.pdf |
| _version_ | 1818271800741593088 |
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| author | Z. Ulanowski J. Bailey P. W. Lucas J. H. Hough E. Hirst |
| author_facet | Z. Ulanowski J. Bailey P. W. Lucas J. H. Hough E. Hirst |
| author_sort | Z. Ulanowski |
| collection | DOAJ |
| description | Optical polarimetry observations on La Palma, Canary Islands, during a Saharan dust episode show dichroic extinction indicating the presence of vertically aligned particles in the atmosphere. Modelling of the extinction together with particle orientation indicates that the alignment could have been due to an electric field of the order of 2 kV/m. Two alternative mechanisms for the origin of the field are examined: the effect of reduced atmospheric conductivity and charging of the dust layer, the latter effect being a more likely candidate. It is concluded that partial alignment may be a common feature of Saharan dust layers. The modelling indicates that the alignment can significantly alter dust optical depth. This "Venetian blind effect" may have decreased optical thickness in the vertical direction by as much as 10% for the case reported here. It is also possible that the alignment and the electric field modify dust transport. |
| first_indexed | 2024-12-12T21:31:56Z |
| format | Article |
| id | doaj.art-f24153dad19244438b2d76c87d5ebc52 |
| institution | Directory Open Access Journal |
| issn | 1680-7316 1680-7324 |
| language | English |
| last_indexed | 2024-12-12T21:31:56Z |
| publishDate | 2007-12-01 |
| publisher | Copernicus Publications |
| record_format | Article |
| series | Atmospheric Chemistry and Physics |
| spelling | doaj.art-f24153dad19244438b2d76c87d5ebc522022-12-22T00:11:18ZengCopernicus PublicationsAtmospheric Chemistry and Physics1680-73161680-73242007-12-0172461616173Alignment of atmospheric mineral dust due to electric fieldZ. UlanowskiJ. BaileyP. W. LucasJ. H. HoughE. HirstOptical polarimetry observations on La Palma, Canary Islands, during a Saharan dust episode show dichroic extinction indicating the presence of vertically aligned particles in the atmosphere. Modelling of the extinction together with particle orientation indicates that the alignment could have been due to an electric field of the order of 2 kV/m. Two alternative mechanisms for the origin of the field are examined: the effect of reduced atmospheric conductivity and charging of the dust layer, the latter effect being a more likely candidate. It is concluded that partial alignment may be a common feature of Saharan dust layers. The modelling indicates that the alignment can significantly alter dust optical depth. This "Venetian blind effect" may have decreased optical thickness in the vertical direction by as much as 10% for the case reported here. It is also possible that the alignment and the electric field modify dust transport.http://www.atmos-chem-phys.net/7/6161/2007/acp-7-6161-2007.pdf |
| spellingShingle | Z. Ulanowski J. Bailey P. W. Lucas J. H. Hough E. Hirst Alignment of atmospheric mineral dust due to electric field Atmospheric Chemistry and Physics |
| title | Alignment of atmospheric mineral dust due to electric field |
| title_full | Alignment of atmospheric mineral dust due to electric field |
| title_fullStr | Alignment of atmospheric mineral dust due to electric field |
| title_full_unstemmed | Alignment of atmospheric mineral dust due to electric field |
| title_short | Alignment of atmospheric mineral dust due to electric field |
| title_sort | alignment of atmospheric mineral dust due to electric field |
| url | http://www.atmos-chem-phys.net/7/6161/2007/acp-7-6161-2007.pdf |
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