Barriers to predicting changes in global terrestrial methane fluxes: Analyses using CLM4Me, a methane biogeochemistry model integrated in CESM
Terrestrial net CH₄ surface fluxes often represent the difference between much larger gross production and consumption fluxes and depend on multiple physical, biological, and chemical mechanisms that are poorly understood and represented in regional- and global-scale biogeochemical models. To charac...
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ftncar:oai:drupal-site.org:articles_10845 2023-09-05T13:23:44+02:00 Barriers to predicting changes in global terrestrial methane fluxes: Analyses using CLM4Me, a methane biogeochemistry model integrated in CESM Riley, W. (author) Subin, Z. (author) Lawrence, David (author) Swenson, Sean (author) Torn, M. (author) Meng, L. (author) Mahowald, N. (author) Hess, P. (author) 2011-07-20 application/pdf http://nldr.library.ucar.edu/repository/collections/OSGC-000-000-003-652 https://doi.org/10.5194/bg-8-1925-2011 en eng Copernicus Publications Biogeosciences http://nldr.library.ucar.edu/repository/collections/OSGC-000-000-003-652 doi:10.5194/bg-8-1925-2011 ark:/85065/d7r211z0 Copyright Authors 2011. This work is distributed under the Creative Commons Attribution 3.0 License. Text article 2011 ftncar https://doi.org/10.5194/bg-8-1925-2011 2023-08-14T18:38:10Z Terrestrial net CH₄ surface fluxes often represent the difference between much larger gross production and consumption fluxes and depend on multiple physical, biological, and chemical mechanisms that are poorly understood and represented in regional- and global-scale biogeochemical models. To characterize uncertainties, study feedbacks between CH₄ fluxes and climate, and to guide future model development and experimentation, we developed and tested a new CH₄ biogeochemistry model (CLM4Me) integrated in the land component (Community Land Model; CLM4) of the Community Earth System Model (CESM1). CLM4Me includes representations of CH₄ production, oxidation, aerenchyma transport, ebullition, aqueous and gaseous diffusion, and fractional inundation. As with most global models, CLM4 lacks important features for predicting current and future CH₄ fluxes, including: vertical representation of soil organic matter, accurate subgrid scale hydrology, realistic representation of inundated system vegetation, anaerobic decomposition, thermokarst dynamics, and aqueous chemistry. We compared the seasonality and magnitude of predicted CH₄ emissions to observations from 18 sites and three global atmospheric inversions. Simulated net CH₄ emissions using our baseline parameter set were 270, 160, 50, and 70 Tg CH₄ yr⁻¹ globally, in the tropics, in the temperate zone, and north of 45° N, respectively; these values are within the range of previous estimates. We then used the model to characterize the sensitivity of regional and global CH₄ emission estimates to uncertainties in model parameterizations. Of the parameters we tested, the temperature sensitivity of CH₄ production, oxidation parameters, and aerenchyma properties had the largest impacts on net CH₄ emissions, up to a factor of 4 and 10 at the regional and gridcell scales, respectively. In spite of these uncertainties, we were able to demonstrate that emissions from dissolved CH₄ in the transpiration stream are small (<1 Tg CH₄ yr⁻¹) and that uncertainty in CH₄ emissions from ... Article in Journal/Newspaper Thermokarst OpenSky (NCAR/UCAR - National Center for Atmospheric Research/University Corporation for Atmospheric Research) Biogeosciences 8 7 1925 1953 |
institution |
Open Polar |
collection |
OpenSky (NCAR/UCAR - National Center for Atmospheric Research/University Corporation for Atmospheric Research) |
op_collection_id |
ftncar |
language |
English |
description |
Terrestrial net CH₄ surface fluxes often represent the difference between much larger gross production and consumption fluxes and depend on multiple physical, biological, and chemical mechanisms that are poorly understood and represented in regional- and global-scale biogeochemical models. To characterize uncertainties, study feedbacks between CH₄ fluxes and climate, and to guide future model development and experimentation, we developed and tested a new CH₄ biogeochemistry model (CLM4Me) integrated in the land component (Community Land Model; CLM4) of the Community Earth System Model (CESM1). CLM4Me includes representations of CH₄ production, oxidation, aerenchyma transport, ebullition, aqueous and gaseous diffusion, and fractional inundation. As with most global models, CLM4 lacks important features for predicting current and future CH₄ fluxes, including: vertical representation of soil organic matter, accurate subgrid scale hydrology, realistic representation of inundated system vegetation, anaerobic decomposition, thermokarst dynamics, and aqueous chemistry. We compared the seasonality and magnitude of predicted CH₄ emissions to observations from 18 sites and three global atmospheric inversions. Simulated net CH₄ emissions using our baseline parameter set were 270, 160, 50, and 70 Tg CH₄ yr⁻¹ globally, in the tropics, in the temperate zone, and north of 45° N, respectively; these values are within the range of previous estimates. We then used the model to characterize the sensitivity of regional and global CH₄ emission estimates to uncertainties in model parameterizations. Of the parameters we tested, the temperature sensitivity of CH₄ production, oxidation parameters, and aerenchyma properties had the largest impacts on net CH₄ emissions, up to a factor of 4 and 10 at the regional and gridcell scales, respectively. In spite of these uncertainties, we were able to demonstrate that emissions from dissolved CH₄ in the transpiration stream are small (<1 Tg CH₄ yr⁻¹) and that uncertainty in CH₄ emissions from ... |
author2 |
Riley, W. (author) Subin, Z. (author) Lawrence, David (author) Swenson, Sean (author) Torn, M. (author) Meng, L. (author) Mahowald, N. (author) Hess, P. (author) |
format |
Article in Journal/Newspaper |
title |
Barriers to predicting changes in global terrestrial methane fluxes: Analyses using CLM4Me, a methane biogeochemistry model integrated in CESM |
spellingShingle |
Barriers to predicting changes in global terrestrial methane fluxes: Analyses using CLM4Me, a methane biogeochemistry model integrated in CESM |
title_short |
Barriers to predicting changes in global terrestrial methane fluxes: Analyses using CLM4Me, a methane biogeochemistry model integrated in CESM |
title_full |
Barriers to predicting changes in global terrestrial methane fluxes: Analyses using CLM4Me, a methane biogeochemistry model integrated in CESM |
title_fullStr |
Barriers to predicting changes in global terrestrial methane fluxes: Analyses using CLM4Me, a methane biogeochemistry model integrated in CESM |
title_full_unstemmed |
Barriers to predicting changes in global terrestrial methane fluxes: Analyses using CLM4Me, a methane biogeochemistry model integrated in CESM |
title_sort |
barriers to predicting changes in global terrestrial methane fluxes: analyses using clm4me, a methane biogeochemistry model integrated in cesm |
publisher |
Copernicus Publications |
publishDate |
2011 |
url |
http://nldr.library.ucar.edu/repository/collections/OSGC-000-000-003-652 https://doi.org/10.5194/bg-8-1925-2011 |
genre |
Thermokarst |
genre_facet |
Thermokarst |
op_relation |
Biogeosciences http://nldr.library.ucar.edu/repository/collections/OSGC-000-000-003-652 doi:10.5194/bg-8-1925-2011 ark:/85065/d7r211z0 |
op_rights |
Copyright Authors 2011. This work is distributed under the Creative Commons Attribution 3.0 License. |
op_doi |
https://doi.org/10.5194/bg-8-1925-2011 |
container_title |
Biogeosciences |
container_volume |
8 |
container_issue |
7 |
container_start_page |
1925 |
op_container_end_page |
1953 |
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1776204318038294528 |