Determining the surface mixing layer height of the Arctic atmospheric boundary layer during polar night in cloudless and cloudy conditions
This study evaluates methods to derive the surface mixing layer (SML) height of the Arctic atmospheric boundary layer (ABL) using in situ measurements inside the Arctic ABL during winter and the transition period to spring. An instrumental payload carried by a tethered balloon was used for the measu...
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ftcopernicus:oai:publications.copernicus.org:egusphere110584 2024-01-21T10:03:03+01:00 Determining the surface mixing layer height of the Arctic atmospheric boundary layer during polar night in cloudless and cloudy conditions Akansu, Elisa F. Dahlke, Sandro Siebert, Holger Wendisch, Manfred 2023-12-19 application/pdf https://doi.org/10.5194/egusphere-2023-629 https://egusphere.copernicus.org/preprints/2023/egusphere-2023-629/ eng eng doi:10.5194/egusphere-2023-629 https://egusphere.copernicus.org/preprints/2023/egusphere-2023-629/ eISSN: Text 2023 ftcopernicus https://doi.org/10.5194/egusphere-2023-629 2023-12-25T17:24:18Z This study evaluates methods to derive the surface mixing layer (SML) height of the Arctic atmospheric boundary layer (ABL) using in situ measurements inside the Arctic ABL during winter and the transition period to spring. An instrumental payload carried by a tethered balloon was used for the measurements between December 2019 and May 2020 during the year-long Multidisciplinary drifting Observatory for the Study of Arctic Climate (MOSAiC) expedition. Vertically highly resolved (centimeter scale) in situ profile measurements of mean and turbulent parameters were obtained, reaching from the sea ice to several hundred meters above ground. Two typical conditions of the Arctic ABL over sea ice were identified: cloudless situations with a shallow surface-based inversion and cloudy conditions with an elevated inversion. Both conditions are associated with significantly different SML heights whose determination as accurately as possible is of great importance for many applications. We used the measured turbulence profile data to define a reference of the SML height. With this reference, a more precise critical bulk Richardson number of 0.12 was derived, which allows an extension of the SML height determination to regular radiosoundings. Furthermore, we have tested the applicability of the Monin–Obukhov similarity theory to derive SML heights based on measured turbulent surface fluxes. The application of the different approaches and their advantages and disadvantages are discussed. Text Arctic polar night Sea ice Copernicus Publications: E-Journals Arctic |
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Copernicus Publications: E-Journals |
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English |
description |
This study evaluates methods to derive the surface mixing layer (SML) height of the Arctic atmospheric boundary layer (ABL) using in situ measurements inside the Arctic ABL during winter and the transition period to spring. An instrumental payload carried by a tethered balloon was used for the measurements between December 2019 and May 2020 during the year-long Multidisciplinary drifting Observatory for the Study of Arctic Climate (MOSAiC) expedition. Vertically highly resolved (centimeter scale) in situ profile measurements of mean and turbulent parameters were obtained, reaching from the sea ice to several hundred meters above ground. Two typical conditions of the Arctic ABL over sea ice were identified: cloudless situations with a shallow surface-based inversion and cloudy conditions with an elevated inversion. Both conditions are associated with significantly different SML heights whose determination as accurately as possible is of great importance for many applications. We used the measured turbulence profile data to define a reference of the SML height. With this reference, a more precise critical bulk Richardson number of 0.12 was derived, which allows an extension of the SML height determination to regular radiosoundings. Furthermore, we have tested the applicability of the Monin–Obukhov similarity theory to derive SML heights based on measured turbulent surface fluxes. The application of the different approaches and their advantages and disadvantages are discussed. |
format |
Text |
author |
Akansu, Elisa F. Dahlke, Sandro Siebert, Holger Wendisch, Manfred |
spellingShingle |
Akansu, Elisa F. Dahlke, Sandro Siebert, Holger Wendisch, Manfred Determining the surface mixing layer height of the Arctic atmospheric boundary layer during polar night in cloudless and cloudy conditions |
author_facet |
Akansu, Elisa F. Dahlke, Sandro Siebert, Holger Wendisch, Manfred |
author_sort |
Akansu, Elisa F. |
title |
Determining the surface mixing layer height of the Arctic atmospheric boundary layer during polar night in cloudless and cloudy conditions |
title_short |
Determining the surface mixing layer height of the Arctic atmospheric boundary layer during polar night in cloudless and cloudy conditions |
title_full |
Determining the surface mixing layer height of the Arctic atmospheric boundary layer during polar night in cloudless and cloudy conditions |
title_fullStr |
Determining the surface mixing layer height of the Arctic atmospheric boundary layer during polar night in cloudless and cloudy conditions |
title_full_unstemmed |
Determining the surface mixing layer height of the Arctic atmospheric boundary layer during polar night in cloudless and cloudy conditions |
title_sort |
determining the surface mixing layer height of the arctic atmospheric boundary layer during polar night in cloudless and cloudy conditions |
publishDate |
2023 |
url |
https://doi.org/10.5194/egusphere-2023-629 https://egusphere.copernicus.org/preprints/2023/egusphere-2023-629/ |
geographic |
Arctic |
geographic_facet |
Arctic |
genre |
Arctic polar night Sea ice |
genre_facet |
Arctic polar night Sea ice |
op_source |
eISSN: |
op_relation |
doi:10.5194/egusphere-2023-629 https://egusphere.copernicus.org/preprints/2023/egusphere-2023-629/ |
op_doi |
https://doi.org/10.5194/egusphere-2023-629 |
_version_ |
1788693311635062784 |