Clear-sky stable boundary layers with low winds over snow-covered surfaces. Part 2: Process sensitivity
This study evaluates the relative impact of snow-surface coupling, long-wave radiation, and turbulent mixing on the development of the stable boundary layer over snow. Observations at three sites are compared to WRF single-column model (SCM) simulations. All three sites have snow-covered surfaces bu...
Published in: | Quarterly Journal of the Royal Meteorological Society |
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Online Access: | https://pure.uhi.ac.uk/en/publications/aeba872c-8282-4820-aa06-89840b71c61f https://doi.org/10.1002/qj.2684 |
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ftuhipublicatio:oai:pure.atira.dk:publications/aeba872c-8282-4820-aa06-89840b71c61f 2024-02-04T09:55:43+01:00 Clear-sky stable boundary layers with low winds over snow-covered surfaces. Part 2: Process sensitivity Sterk, H. A. M. Steeneveld, G. J. Bosveld, F. C. Vihma, T. Anderson, Philip Holtslag, A. A. M. 2015-12-29 https://pure.uhi.ac.uk/en/publications/aeba872c-8282-4820-aa06-89840b71c61f https://doi.org/10.1002/qj.2684 eng eng info:eu-repo/semantics/closedAccess Sterk , H A M , Steeneveld , G J , Bosveld , F C , Vihma , T , Anderson , P & Holtslag , A A M 2015 , ' Clear-sky stable boundary layers with low winds over snow-covered surfaces. Part 2: Process sensitivity ' , Quarterly Journal of the Royal Meteorological Society , vol. n/a , no. n/a . https://doi.org/10.1002/qj.2684 article 2015 ftuhipublicatio https://doi.org/10.1002/qj.2684 2024-01-11T23:21:10Z This study evaluates the relative impact of snow-surface coupling, long-wave radiation, and turbulent mixing on the development of the stable boundary layer over snow. Observations at three sites are compared to WRF single-column model (SCM) simulations. All three sites have snow-covered surfaces but are otherwise contrasting: Cabauw (Netherlands, grass), Sodankylä (Finland, needle-leaf forest) and Halley (Antarctica, ice shelf). All cases are characterized by stable, clear-sky, and calm conditions. Part 1 of this study determined the optimal SCM forcing strategy. In this study, the process intensities from that reference are perturbed to study their relative significance and to assess which process could be responsible for the most optimal agreement between model and observation. The analysis reveals a large variability in the modelled atmospheric state and surface parameters. Overall, the modelled gradients of temperature and moisture are underestimated but decreasing the process intensities improves this. The impact is strongest with reduced mixing, though this then causes the model to overestimate the near-surface wind speed. To study the surface energy balance terms, we use so-called ‘process diagrams’. The achieved variation between the sensitivity runs indicates the model sensitivity to each process. The overall sensitivity is similar for the three sites but the relative offsets in the position of the sensitivity runs with respect to the observations differ, hampering general recommendations for model improvement. Furthermore, sometimes a meaningful interpretation of observations is troublesome, which hampers the comparison with model results. Radiation is relatively more important at Cabauw and Sodankylä, whilst coupling plays a more important role at Halley. The sensitivity analysis is performed with two boundary-layer schemes (MYJ, YSU). YSU generates larger, more accurate gradients of atmospheric temperature and humidity, while wind speeds are predicted better with MYJ. The behaviour of an increase in ... Article in Journal/Newspaper Antarc* Antarctica Ice Shelf Sodankylä University of the Highlands and Islands: Research Database of UHI Sodankylä ENVELOPE(26.600,26.600,67.417,67.417) Quarterly Journal of the Royal Meteorological Society 142 695 821 835 |
institution |
Open Polar |
collection |
University of the Highlands and Islands: Research Database of UHI |
op_collection_id |
ftuhipublicatio |
language |
English |
description |
This study evaluates the relative impact of snow-surface coupling, long-wave radiation, and turbulent mixing on the development of the stable boundary layer over snow. Observations at three sites are compared to WRF single-column model (SCM) simulations. All three sites have snow-covered surfaces but are otherwise contrasting: Cabauw (Netherlands, grass), Sodankylä (Finland, needle-leaf forest) and Halley (Antarctica, ice shelf). All cases are characterized by stable, clear-sky, and calm conditions. Part 1 of this study determined the optimal SCM forcing strategy. In this study, the process intensities from that reference are perturbed to study their relative significance and to assess which process could be responsible for the most optimal agreement between model and observation. The analysis reveals a large variability in the modelled atmospheric state and surface parameters. Overall, the modelled gradients of temperature and moisture are underestimated but decreasing the process intensities improves this. The impact is strongest with reduced mixing, though this then causes the model to overestimate the near-surface wind speed. To study the surface energy balance terms, we use so-called ‘process diagrams’. The achieved variation between the sensitivity runs indicates the model sensitivity to each process. The overall sensitivity is similar for the three sites but the relative offsets in the position of the sensitivity runs with respect to the observations differ, hampering general recommendations for model improvement. Furthermore, sometimes a meaningful interpretation of observations is troublesome, which hampers the comparison with model results. Radiation is relatively more important at Cabauw and Sodankylä, whilst coupling plays a more important role at Halley. The sensitivity analysis is performed with two boundary-layer schemes (MYJ, YSU). YSU generates larger, more accurate gradients of atmospheric temperature and humidity, while wind speeds are predicted better with MYJ. The behaviour of an increase in ... |
format |
Article in Journal/Newspaper |
author |
Sterk, H. A. M. Steeneveld, G. J. Bosveld, F. C. Vihma, T. Anderson, Philip Holtslag, A. A. M. |
spellingShingle |
Sterk, H. A. M. Steeneveld, G. J. Bosveld, F. C. Vihma, T. Anderson, Philip Holtslag, A. A. M. Clear-sky stable boundary layers with low winds over snow-covered surfaces. Part 2: Process sensitivity |
author_facet |
Sterk, H. A. M. Steeneveld, G. J. Bosveld, F. C. Vihma, T. Anderson, Philip Holtslag, A. A. M. |
author_sort |
Sterk, H. A. M. |
title |
Clear-sky stable boundary layers with low winds over snow-covered surfaces. Part 2: Process sensitivity |
title_short |
Clear-sky stable boundary layers with low winds over snow-covered surfaces. Part 2: Process sensitivity |
title_full |
Clear-sky stable boundary layers with low winds over snow-covered surfaces. Part 2: Process sensitivity |
title_fullStr |
Clear-sky stable boundary layers with low winds over snow-covered surfaces. Part 2: Process sensitivity |
title_full_unstemmed |
Clear-sky stable boundary layers with low winds over snow-covered surfaces. Part 2: Process sensitivity |
title_sort |
clear-sky stable boundary layers with low winds over snow-covered surfaces. part 2: process sensitivity |
publishDate |
2015 |
url |
https://pure.uhi.ac.uk/en/publications/aeba872c-8282-4820-aa06-89840b71c61f https://doi.org/10.1002/qj.2684 |
long_lat |
ENVELOPE(26.600,26.600,67.417,67.417) |
geographic |
Sodankylä |
geographic_facet |
Sodankylä |
genre |
Antarc* Antarctica Ice Shelf Sodankylä |
genre_facet |
Antarc* Antarctica Ice Shelf Sodankylä |
op_source |
Sterk , H A M , Steeneveld , G J , Bosveld , F C , Vihma , T , Anderson , P & Holtslag , A A M 2015 , ' Clear-sky stable boundary layers with low winds over snow-covered surfaces. Part 2: Process sensitivity ' , Quarterly Journal of the Royal Meteorological Society , vol. n/a , no. n/a . https://doi.org/10.1002/qj.2684 |
op_rights |
info:eu-repo/semantics/closedAccess |
op_doi |
https://doi.org/10.1002/qj.2684 |
container_title |
Quarterly Journal of the Royal Meteorological Society |
container_volume |
142 |
container_issue |
695 |
container_start_page |
821 |
op_container_end_page |
835 |
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1789959821282246656 |