Brief communication: Two well-marked cases of aerodynamic adjustment of sastrugi
In polar regions, sastrugi are a direct manifestation of drifting snow and form the main surface roughness elements. In turn, sastrugi alter the generation of atmospheric turbulence and thus modify the wind field and the aeolian snow mass fluxes. Little attention has been paid to these feedback proc...
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ftdoajarticles:oai:doaj.org/article:131f1aae912c4585b0422b8bd06602e6 2023-05-15T13:58:55+02:00 Brief communication: Two well-marked cases of aerodynamic adjustment of sastrugi C. Amory F. Naaim-Bouvet H. Gallée E. Vignon 2016-04-01T00:00:00Z https://doi.org/10.5194/tc-10-743-2016 https://doaj.org/article/131f1aae912c4585b0422b8bd06602e6 EN eng Copernicus Publications http://www.the-cryosphere.net/10/743/2016/tc-10-743-2016.pdf https://doaj.org/toc/1994-0416 https://doaj.org/toc/1994-0424 1994-0416 1994-0424 doi:10.5194/tc-10-743-2016 https://doaj.org/article/131f1aae912c4585b0422b8bd06602e6 The Cryosphere, Vol 10, Iss 2, Pp 743-750 (2016) Environmental sciences GE1-350 Geology QE1-996.5 article 2016 ftdoajarticles https://doi.org/10.5194/tc-10-743-2016 2022-12-31T12:09:46Z In polar regions, sastrugi are a direct manifestation of drifting snow and form the main surface roughness elements. In turn, sastrugi alter the generation of atmospheric turbulence and thus modify the wind field and the aeolian snow mass fluxes. Little attention has been paid to these feedback processes, mainly because of experimental difficulties. As a result, most polar atmospheric models currently ignore sastrugi over snow-covered regions. This paper aims at quantifying the potential influence of sastrugi on the local wind field and on snow erosion over a sastrugi-covered snowfield in coastal Adélie Land, East Antarctica. We focus on two erosion events during which sastrugi responses to shifts in wind direction have been interpreted from temporal variations in drag and aeolian snow mass flux measurements during austral winter 2013. Using this data set, it is shown that (i) neutral stability, 10 m drag coefficient ( C DN10 ) values are in the range of 1.3–1.5 × 10 −3 when the wind is well aligned with the sastrugi, (ii) as the wind shifts by only 20–30° away from the streamlined direction, C DN10 increases (by 30–120 %) and the aeolian snow mass flux decreases (by 30–80 %), thereby reflecting the growing contribution of the sastrugi form drag to the total surface drag and its inhibiting effect on snow erosion, (iii) the timescale of sastrugi aerodynamic adjustment can be as short as 3 h for friction velocities greater than 1 m s −1 and during strong drifting snow conditions and (iv) knowing C DN10 is not sufficient to estimate the snow erosion flux that results from drag partitioning at the surface because C DN10 includes the contribution of the sastrugi form drag. Article in Journal/Newspaper Antarc* Antarctica East Antarctica The Cryosphere Directory of Open Access Journals: DOAJ Articles East Antarctica Austral Sastrugi ENVELOPE(163.683,163.683,-74.617,-74.617) The Cryosphere 10 2 743 750 |
institution |
Open Polar |
collection |
Directory of Open Access Journals: DOAJ Articles |
op_collection_id |
ftdoajarticles |
language |
English |
topic |
Environmental sciences GE1-350 Geology QE1-996.5 |
spellingShingle |
Environmental sciences GE1-350 Geology QE1-996.5 C. Amory F. Naaim-Bouvet H. Gallée E. Vignon Brief communication: Two well-marked cases of aerodynamic adjustment of sastrugi |
topic_facet |
Environmental sciences GE1-350 Geology QE1-996.5 |
description |
In polar regions, sastrugi are a direct manifestation of drifting snow and form the main surface roughness elements. In turn, sastrugi alter the generation of atmospheric turbulence and thus modify the wind field and the aeolian snow mass fluxes. Little attention has been paid to these feedback processes, mainly because of experimental difficulties. As a result, most polar atmospheric models currently ignore sastrugi over snow-covered regions. This paper aims at quantifying the potential influence of sastrugi on the local wind field and on snow erosion over a sastrugi-covered snowfield in coastal Adélie Land, East Antarctica. We focus on two erosion events during which sastrugi responses to shifts in wind direction have been interpreted from temporal variations in drag and aeolian snow mass flux measurements during austral winter 2013. Using this data set, it is shown that (i) neutral stability, 10 m drag coefficient ( C DN10 ) values are in the range of 1.3–1.5 × 10 −3 when the wind is well aligned with the sastrugi, (ii) as the wind shifts by only 20–30° away from the streamlined direction, C DN10 increases (by 30–120 %) and the aeolian snow mass flux decreases (by 30–80 %), thereby reflecting the growing contribution of the sastrugi form drag to the total surface drag and its inhibiting effect on snow erosion, (iii) the timescale of sastrugi aerodynamic adjustment can be as short as 3 h for friction velocities greater than 1 m s −1 and during strong drifting snow conditions and (iv) knowing C DN10 is not sufficient to estimate the snow erosion flux that results from drag partitioning at the surface because C DN10 includes the contribution of the sastrugi form drag. |
format |
Article in Journal/Newspaper |
author |
C. Amory F. Naaim-Bouvet H. Gallée E. Vignon |
author_facet |
C. Amory F. Naaim-Bouvet H. Gallée E. Vignon |
author_sort |
C. Amory |
title |
Brief communication: Two well-marked cases of aerodynamic adjustment of sastrugi |
title_short |
Brief communication: Two well-marked cases of aerodynamic adjustment of sastrugi |
title_full |
Brief communication: Two well-marked cases of aerodynamic adjustment of sastrugi |
title_fullStr |
Brief communication: Two well-marked cases of aerodynamic adjustment of sastrugi |
title_full_unstemmed |
Brief communication: Two well-marked cases of aerodynamic adjustment of sastrugi |
title_sort |
brief communication: two well-marked cases of aerodynamic adjustment of sastrugi |
publisher |
Copernicus Publications |
publishDate |
2016 |
url |
https://doi.org/10.5194/tc-10-743-2016 https://doaj.org/article/131f1aae912c4585b0422b8bd06602e6 |
long_lat |
ENVELOPE(163.683,163.683,-74.617,-74.617) |
geographic |
East Antarctica Austral Sastrugi |
geographic_facet |
East Antarctica Austral Sastrugi |
genre |
Antarc* Antarctica East Antarctica The Cryosphere |
genre_facet |
Antarc* Antarctica East Antarctica The Cryosphere |
op_source |
The Cryosphere, Vol 10, Iss 2, Pp 743-750 (2016) |
op_relation |
http://www.the-cryosphere.net/10/743/2016/tc-10-743-2016.pdf https://doaj.org/toc/1994-0416 https://doaj.org/toc/1994-0424 1994-0416 1994-0424 doi:10.5194/tc-10-743-2016 https://doaj.org/article/131f1aae912c4585b0422b8bd06602e6 |
op_doi |
https://doi.org/10.5194/tc-10-743-2016 |
container_title |
The Cryosphere |
container_volume |
10 |
container_issue |
2 |
container_start_page |
743 |
op_container_end_page |
750 |
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1766267281323589632 |