Choosing an optimal β factor for relaxed eddy accumulation applications across vegetated and non-vegetated surfaces
Accurately measuring the turbulent transport of reactive and conservative greenhouse gases, heat, and organic compounds between the surface and the atmosphere is critical for understanding trace gas exchange and its response to changes in climate and anthropogenic activities. The relaxed eddy accumu...
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ftdoajarticles:oai:doaj.org/article:788e37dec0a8482282ce5963470d32e6 2023-05-15T13:37:25+02:00 Choosing an optimal β factor for relaxed eddy accumulation applications across vegetated and non-vegetated surfaces T. Vogl A. Hrdina C. K. Thomas 2021-09-01T00:00:00Z https://doi.org/10.5194/bg-18-5097-2021 https://doaj.org/article/788e37dec0a8482282ce5963470d32e6 EN eng Copernicus Publications https://bg.copernicus.org/articles/18/5097/2021/bg-18-5097-2021.pdf https://doaj.org/toc/1726-4170 https://doaj.org/toc/1726-4189 doi:10.5194/bg-18-5097-2021 1726-4170 1726-4189 https://doaj.org/article/788e37dec0a8482282ce5963470d32e6 Biogeosciences, Vol 18, Pp 5097-5115 (2021) Ecology QH540-549.5 Life QH501-531 Geology QE1-996.5 article 2021 ftdoajarticles https://doi.org/10.5194/bg-18-5097-2021 2022-12-31T07:10:19Z Accurately measuring the turbulent transport of reactive and conservative greenhouse gases, heat, and organic compounds between the surface and the atmosphere is critical for understanding trace gas exchange and its response to changes in climate and anthropogenic activities. The relaxed eddy accumulation (REA) method enables measuring the land surface exchange when fast-response sensors are not available, broadening the suite of trace gases that can be investigated. The β factor scales the concentration differences to the flux, and its choice is central to successfully using REA. Deadbands are used to select only certain turbulent motions to compute the flux. This study evaluates a variety of different REA approaches with the goal of formulating recommendations applicable over a wide range of surfaces and meteorological conditions for an optimal choice of the β factor in combination with a suitable deadband. Observations were collected across three contrasting ecosystems offering stark differences in scalar transport and dynamics: a mid-latitude grassland ecosystem in Europe, a loose gravel surface of the Dry Valleys of Antarctica, and a spruce forest site in the European mid-range mountains. We tested a total of four different REA models for the β factor: the first two methods, referred to as model 1 and model 2, derive β p based on a proxy p for which high-frequency observations are available (sensible heat T s ). In the first case, a linear deadband is applied, while in the second case, we are using a hyperbolic deadband. The third method, model 3, employs the approach first published by Baker et al. ( 1992 ) , which computes β w solely based upon the vertical wind statistics. The fourth method, model 4, uses a constant β p, const derived from long-term averaging of the proxy-based β p factor. Each β model was optimized with respect to deadband size before intercomparison. To our best knowledge, this is the first study intercomparing these different approaches over a range of different sites. With respect to ... Article in Journal/Newspaper Antarc* Antarctica Directory of Open Access Journals: DOAJ Articles Biogeosciences 18 18 5097 5115 |
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Ecology QH540-549.5 Life QH501-531 Geology QE1-996.5 |
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Ecology QH540-549.5 Life QH501-531 Geology QE1-996.5 T. Vogl A. Hrdina C. K. Thomas Choosing an optimal β factor for relaxed eddy accumulation applications across vegetated and non-vegetated surfaces |
topic_facet |
Ecology QH540-549.5 Life QH501-531 Geology QE1-996.5 |
description |
Accurately measuring the turbulent transport of reactive and conservative greenhouse gases, heat, and organic compounds between the surface and the atmosphere is critical for understanding trace gas exchange and its response to changes in climate and anthropogenic activities. The relaxed eddy accumulation (REA) method enables measuring the land surface exchange when fast-response sensors are not available, broadening the suite of trace gases that can be investigated. The β factor scales the concentration differences to the flux, and its choice is central to successfully using REA. Deadbands are used to select only certain turbulent motions to compute the flux. This study evaluates a variety of different REA approaches with the goal of formulating recommendations applicable over a wide range of surfaces and meteorological conditions for an optimal choice of the β factor in combination with a suitable deadband. Observations were collected across three contrasting ecosystems offering stark differences in scalar transport and dynamics: a mid-latitude grassland ecosystem in Europe, a loose gravel surface of the Dry Valleys of Antarctica, and a spruce forest site in the European mid-range mountains. We tested a total of four different REA models for the β factor: the first two methods, referred to as model 1 and model 2, derive β p based on a proxy p for which high-frequency observations are available (sensible heat T s ). In the first case, a linear deadband is applied, while in the second case, we are using a hyperbolic deadband. The third method, model 3, employs the approach first published by Baker et al. ( 1992 ) , which computes β w solely based upon the vertical wind statistics. The fourth method, model 4, uses a constant β p, const derived from long-term averaging of the proxy-based β p factor. Each β model was optimized with respect to deadband size before intercomparison. To our best knowledge, this is the first study intercomparing these different approaches over a range of different sites. With respect to ... |
format |
Article in Journal/Newspaper |
author |
T. Vogl A. Hrdina C. K. Thomas |
author_facet |
T. Vogl A. Hrdina C. K. Thomas |
author_sort |
T. Vogl |
title |
Choosing an optimal β factor for relaxed eddy accumulation applications across vegetated and non-vegetated surfaces |
title_short |
Choosing an optimal β factor for relaxed eddy accumulation applications across vegetated and non-vegetated surfaces |
title_full |
Choosing an optimal β factor for relaxed eddy accumulation applications across vegetated and non-vegetated surfaces |
title_fullStr |
Choosing an optimal β factor for relaxed eddy accumulation applications across vegetated and non-vegetated surfaces |
title_full_unstemmed |
Choosing an optimal β factor for relaxed eddy accumulation applications across vegetated and non-vegetated surfaces |
title_sort |
choosing an optimal β factor for relaxed eddy accumulation applications across vegetated and non-vegetated surfaces |
publisher |
Copernicus Publications |
publishDate |
2021 |
url |
https://doi.org/10.5194/bg-18-5097-2021 https://doaj.org/article/788e37dec0a8482282ce5963470d32e6 |
genre |
Antarc* Antarctica |
genre_facet |
Antarc* Antarctica |
op_source |
Biogeosciences, Vol 18, Pp 5097-5115 (2021) |
op_relation |
https://bg.copernicus.org/articles/18/5097/2021/bg-18-5097-2021.pdf https://doaj.org/toc/1726-4170 https://doaj.org/toc/1726-4189 doi:10.5194/bg-18-5097-2021 1726-4170 1726-4189 https://doaj.org/article/788e37dec0a8482282ce5963470d32e6 |
op_doi |
https://doi.org/10.5194/bg-18-5097-2021 |
container_title |
Biogeosciences |
container_volume |
18 |
container_issue |
18 |
container_start_page |
5097 |
op_container_end_page |
5115 |
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1766091699327598592 |