On the u⋆−U Relationship in the Stable Atmospheric Boundary Layer over Arctic Sea Ice
A relationship between the friction velocity u⋆ and mean wind speed U in a stable atmospheric boundary layer (ABL) over Arctic sea ice was considered. To that aim, the observations collected during the Surface Heat Budget of the Arctic Ocean (SHEBA) experiment were used. The observations showed the...
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ftmdpi:oai:mdpi.com:/2073-4433/12/5/591/ 2023-08-20T04:04:11+02:00 On the u⋆−U Relationship in the Stable Atmospheric Boundary Layer over Arctic Sea Ice Dmitry Chechin agris 2021-05-02 application/pdf https://doi.org/10.3390/atmos12050591 EN eng Multidisciplinary Digital Publishing Institute Atmospheric Techniques, Instruments, and Modeling https://dx.doi.org/10.3390/atmos12050591 https://creativecommons.org/licenses/by/4.0/ Atmosphere; Volume 12; Issue 5; Pages: 591 stable atmospheric boundary layer Monin–Obukhov similarity theory Text 2021 ftmdpi https://doi.org/10.3390/atmos12050591 2023-08-01T01:38:20Z A relationship between the friction velocity u⋆ and mean wind speed U in a stable atmospheric boundary layer (ABL) over Arctic sea ice was considered. To that aim, the observations collected during the Surface Heat Budget of the Arctic Ocean (SHEBA) experiment were used. The observations showed the so-called “hockey-stick” shape of the u⋆−U relationship, which consists of a slow increase of u⋆ with increasing wind speed for U Utr, where Utr is the wind speed of transition between the two regimes. Such a relationship is most pronounced at the highest observational levels, namely at 9 and 14 m, and is also sharper when the air-surface temperature difference exceeds its average values for stable conditions. It is shown that the Monin–Obukhov similarity theory (MOST) reproduces the observed u⋆−U relationship rather well. This suggests that at least for the SHEBA dataset, there is no contradiction between MOST and the “hockey-stick” shape of the u⋆−U relationship. However, the SHEBA data, as well as the single-column simulations show that for cases with strong stability, u⋆ significantly decreases with height due to the shallowness of the ABL. It was shown that when u⋆ was assumed independent of height, the value of the normalized drag coefficient, i.e., of the so-called stability correction function for momentum, calculated using observations at a certain level, can be significantly underestimated. To overcome this, the decrease of u⋆ with height was taken into account in the framework of MOST using local scaling instead of the scaling with surface fluxes. Using such an extended MOST brought the estimates of the normalized drag coefficient closer to the Businger–Dyer relation. Text Arctic Arctic Ocean Sea ice Surface Heat Budget of the Arctic Ocean MDPI Open Access Publishing Arctic Arctic Ocean Dyer ENVELOPE(-81.366,-81.366,50.550,50.550) Atmosphere 12 5 591 |
institution |
Open Polar |
collection |
MDPI Open Access Publishing |
op_collection_id |
ftmdpi |
language |
English |
topic |
stable atmospheric boundary layer Monin–Obukhov similarity theory |
spellingShingle |
stable atmospheric boundary layer Monin–Obukhov similarity theory Dmitry Chechin On the u⋆−U Relationship in the Stable Atmospheric Boundary Layer over Arctic Sea Ice |
topic_facet |
stable atmospheric boundary layer Monin–Obukhov similarity theory |
description |
A relationship between the friction velocity u⋆ and mean wind speed U in a stable atmospheric boundary layer (ABL) over Arctic sea ice was considered. To that aim, the observations collected during the Surface Heat Budget of the Arctic Ocean (SHEBA) experiment were used. The observations showed the so-called “hockey-stick” shape of the u⋆−U relationship, which consists of a slow increase of u⋆ with increasing wind speed for U Utr, where Utr is the wind speed of transition between the two regimes. Such a relationship is most pronounced at the highest observational levels, namely at 9 and 14 m, and is also sharper when the air-surface temperature difference exceeds its average values for stable conditions. It is shown that the Monin–Obukhov similarity theory (MOST) reproduces the observed u⋆−U relationship rather well. This suggests that at least for the SHEBA dataset, there is no contradiction between MOST and the “hockey-stick” shape of the u⋆−U relationship. However, the SHEBA data, as well as the single-column simulations show that for cases with strong stability, u⋆ significantly decreases with height due to the shallowness of the ABL. It was shown that when u⋆ was assumed independent of height, the value of the normalized drag coefficient, i.e., of the so-called stability correction function for momentum, calculated using observations at a certain level, can be significantly underestimated. To overcome this, the decrease of u⋆ with height was taken into account in the framework of MOST using local scaling instead of the scaling with surface fluxes. Using such an extended MOST brought the estimates of the normalized drag coefficient closer to the Businger–Dyer relation. |
format |
Text |
author |
Dmitry Chechin |
author_facet |
Dmitry Chechin |
author_sort |
Dmitry Chechin |
title |
On the u⋆−U Relationship in the Stable Atmospheric Boundary Layer over Arctic Sea Ice |
title_short |
On the u⋆−U Relationship in the Stable Atmospheric Boundary Layer over Arctic Sea Ice |
title_full |
On the u⋆−U Relationship in the Stable Atmospheric Boundary Layer over Arctic Sea Ice |
title_fullStr |
On the u⋆−U Relationship in the Stable Atmospheric Boundary Layer over Arctic Sea Ice |
title_full_unstemmed |
On the u⋆−U Relationship in the Stable Atmospheric Boundary Layer over Arctic Sea Ice |
title_sort |
on the u⋆−u relationship in the stable atmospheric boundary layer over arctic sea ice |
publisher |
Multidisciplinary Digital Publishing Institute |
publishDate |
2021 |
url |
https://doi.org/10.3390/atmos12050591 |
op_coverage |
agris |
long_lat |
ENVELOPE(-81.366,-81.366,50.550,50.550) |
geographic |
Arctic Arctic Ocean Dyer |
geographic_facet |
Arctic Arctic Ocean Dyer |
genre |
Arctic Arctic Ocean Sea ice Surface Heat Budget of the Arctic Ocean |
genre_facet |
Arctic Arctic Ocean Sea ice Surface Heat Budget of the Arctic Ocean |
op_source |
Atmosphere; Volume 12; Issue 5; Pages: 591 |
op_relation |
Atmospheric Techniques, Instruments, and Modeling https://dx.doi.org/10.3390/atmos12050591 |
op_rights |
https://creativecommons.org/licenses/by/4.0/ |
op_doi |
https://doi.org/10.3390/atmos12050591 |
container_title |
Atmosphere |
container_volume |
12 |
container_issue |
5 |
container_start_page |
591 |
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1774714588571369472 |