Impacts of a revised surface roughness parameterization in the Community Land Model 5.1
Abstract. The roughness of the land surface (z0) is a key property, exerting significant influence on the amount of near-surface turbulent activity and consequently the turbulent exchange of energy, water, momentum, and chemical species between the land and the atmosphere. Variations in z0 are subst...
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Online Access: | https://insu.hal.science/insu-04269715 https://doi.org/10.5194/gmd-15-2365-2022 |
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ftccsdartic:oai:HAL:insu-04269715v1 2023-12-03T10:13:05+01:00 Impacts of a revised surface roughness parameterization in the Community Land Model 5.1 Meier, Ronny Davin, Edouard Bonan, Gordon Lawrence, David Hu, Xiaolong Duveiller, Gregory Prigent, Catherine Seneviratne, Sonia Laboratoire d'Etude du Rayonnement et de la Matière en Astrophysique et Atmosphères = Laboratory for Studies of Radiation and Matter in Astrophysics and Atmospheres (LERMA) École normale supérieure - Paris (ENS-PSL) Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire de Paris Université Paris sciences et lettres (PSL)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS)-CY Cergy Paris Université (CY) 2022 https://insu.hal.science/insu-04269715 https://doi.org/10.5194/gmd-15-2365-2022 en eng HAL CCSD European Geosciences Union info:eu-repo/semantics/altIdentifier/doi/10.5194/gmd-15-2365-2022 insu-04269715 https://insu.hal.science/insu-04269715 doi:10.5194/gmd-15-2365-2022 ISSN: 1991-9603 EISSN: 1991-959X Geoscientific Model Development https://insu.hal.science/insu-04269715 Geoscientific Model Development, 2022, 15 (6), pp.2365-2393. ⟨10.5194/gmd-15-2365-2022⟩ [SDE]Environmental Sciences info:eu-repo/semantics/article Journal articles 2022 ftccsdartic https://doi.org/10.5194/gmd-15-2365-2022 2023-11-04T23:27:53Z Abstract. The roughness of the land surface (z0) is a key property, exerting significant influence on the amount of near-surface turbulent activity and consequently the turbulent exchange of energy, water, momentum, and chemical species between the land and the atmosphere. Variations in z0 are substantial across different types of land cover, ranging from typically less than 1 mm over fresh snow or sand deserts up to more than 1 m over urban areas or forests. In this study, we revise the parameterizations and parameter choices related to z0 in the Community Land Model 5.1 (CLM), the land component of the Community Earth System Model (CESM). We propose a number modifications for z0 in CLM, guided by observational data. Most importantly, we find that the observations support an increase in z0 for all types of forests and a decrease in the momentum z0 for bare soil, snow, glaciers, and crops. We then assess the effect of those modifications in land-only and land–atmosphere coupled simulations. With the revised parameterizations, diurnal variations of the land surface temperature (LST) are dampened in forested regions and are amplified over warm deserts. These changes mitigate model biases compared to MODerate resolution Imaging Spectroradiometer (MODIS) remote sensing observations. The changes in LST are generally stronger during the day than at night. For example, the LST increases by 5.1 K at 13:30 local solar time but only by 0.6 K at 01:30 during boreal summer across the entire Sahara. The induced changes in the diurnal variability of near-surface air temperatures are generally of the opposite sign and of smaller magnitude. Near-surface winds accelerate in areas where the momentum z0 was lowered, such as the Sahara, the Middle East, and Antarctica, and decelerate in regions with forests. Overall, this study finds that the current representation of z0 in CLM is not in agreement with observational constraints for several types of land cover. The proposed model modifications are shown to considerably alter the ... Article in Journal/Newspaper Antarc* Antarctica Archive ouverte HAL (Hyper Article en Ligne, CCSD - Centre pour la Communication Scientifique Directe) Geoscientific Model Development 15 6 2365 2393 |
institution |
Open Polar |
collection |
Archive ouverte HAL (Hyper Article en Ligne, CCSD - Centre pour la Communication Scientifique Directe) |
op_collection_id |
ftccsdartic |
language |
English |
topic |
[SDE]Environmental Sciences |
spellingShingle |
[SDE]Environmental Sciences Meier, Ronny Davin, Edouard Bonan, Gordon Lawrence, David Hu, Xiaolong Duveiller, Gregory Prigent, Catherine Seneviratne, Sonia Impacts of a revised surface roughness parameterization in the Community Land Model 5.1 |
topic_facet |
[SDE]Environmental Sciences |
description |
Abstract. The roughness of the land surface (z0) is a key property, exerting significant influence on the amount of near-surface turbulent activity and consequently the turbulent exchange of energy, water, momentum, and chemical species between the land and the atmosphere. Variations in z0 are substantial across different types of land cover, ranging from typically less than 1 mm over fresh snow or sand deserts up to more than 1 m over urban areas or forests. In this study, we revise the parameterizations and parameter choices related to z0 in the Community Land Model 5.1 (CLM), the land component of the Community Earth System Model (CESM). We propose a number modifications for z0 in CLM, guided by observational data. Most importantly, we find that the observations support an increase in z0 for all types of forests and a decrease in the momentum z0 for bare soil, snow, glaciers, and crops. We then assess the effect of those modifications in land-only and land–atmosphere coupled simulations. With the revised parameterizations, diurnal variations of the land surface temperature (LST) are dampened in forested regions and are amplified over warm deserts. These changes mitigate model biases compared to MODerate resolution Imaging Spectroradiometer (MODIS) remote sensing observations. The changes in LST are generally stronger during the day than at night. For example, the LST increases by 5.1 K at 13:30 local solar time but only by 0.6 K at 01:30 during boreal summer across the entire Sahara. The induced changes in the diurnal variability of near-surface air temperatures are generally of the opposite sign and of smaller magnitude. Near-surface winds accelerate in areas where the momentum z0 was lowered, such as the Sahara, the Middle East, and Antarctica, and decelerate in regions with forests. Overall, this study finds that the current representation of z0 in CLM is not in agreement with observational constraints for several types of land cover. The proposed model modifications are shown to considerably alter the ... |
author2 |
Laboratoire d'Etude du Rayonnement et de la Matière en Astrophysique et Atmosphères = Laboratory for Studies of Radiation and Matter in Astrophysics and Atmospheres (LERMA) École normale supérieure - Paris (ENS-PSL) Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire de Paris Université Paris sciences et lettres (PSL)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS)-CY Cergy Paris Université (CY) |
format |
Article in Journal/Newspaper |
author |
Meier, Ronny Davin, Edouard Bonan, Gordon Lawrence, David Hu, Xiaolong Duveiller, Gregory Prigent, Catherine Seneviratne, Sonia |
author_facet |
Meier, Ronny Davin, Edouard Bonan, Gordon Lawrence, David Hu, Xiaolong Duveiller, Gregory Prigent, Catherine Seneviratne, Sonia |
author_sort |
Meier, Ronny |
title |
Impacts of a revised surface roughness parameterization in the Community Land Model 5.1 |
title_short |
Impacts of a revised surface roughness parameterization in the Community Land Model 5.1 |
title_full |
Impacts of a revised surface roughness parameterization in the Community Land Model 5.1 |
title_fullStr |
Impacts of a revised surface roughness parameterization in the Community Land Model 5.1 |
title_full_unstemmed |
Impacts of a revised surface roughness parameterization in the Community Land Model 5.1 |
title_sort |
impacts of a revised surface roughness parameterization in the community land model 5.1 |
publisher |
HAL CCSD |
publishDate |
2022 |
url |
https://insu.hal.science/insu-04269715 https://doi.org/10.5194/gmd-15-2365-2022 |
genre |
Antarc* Antarctica |
genre_facet |
Antarc* Antarctica |
op_source |
ISSN: 1991-9603 EISSN: 1991-959X Geoscientific Model Development https://insu.hal.science/insu-04269715 Geoscientific Model Development, 2022, 15 (6), pp.2365-2393. ⟨10.5194/gmd-15-2365-2022⟩ |
op_relation |
info:eu-repo/semantics/altIdentifier/doi/10.5194/gmd-15-2365-2022 insu-04269715 https://insu.hal.science/insu-04269715 doi:10.5194/gmd-15-2365-2022 |
op_doi |
https://doi.org/10.5194/gmd-15-2365-2022 |
container_title |
Geoscientific Model Development |
container_volume |
15 |
container_issue |
6 |
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2365 |
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2393 |
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