Mechanistic Modeling of Microtopographic Impacts on CO 2 and CH 4 Fluxes in an Alaskan Tundra Ecosystem Using the CLM-Microbe Model
Spatial heterogeneities in soil hydrology have been confirmed as a key control on CO 2 and CH 4 fluxes in the Arctic tundra ecosystem. In this study, we applied a mechanistic ecosystem model, CLM-Microbe, to examine the microtopographic impacts on CO 2 and CH 4 fluxes across seven landscape types in...
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Online Access: | http://www.osti.gov/servlets/purl/1582360 https://www.osti.gov/biblio/1582360 https://doi.org/10.1029/2019ms001771 |
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ftosti:oai:osti.gov:1582360 2023-07-30T04:01:21+02:00 Mechanistic Modeling of Microtopographic Impacts on CO 2 and CH 4 Fluxes in an Alaskan Tundra Ecosystem Using the CLM-Microbe Model Wang, Yihui Yuan, Fengming Yuan, Fenghui Gu, Baohua Hahn, Melanie S. Torn, Margaret S. Ricciuto, Daniel M. Kumar, Jitendra He, Liyuan Zona, Donatella Lipson, David A. Wagner, Robert Oechel, Walter C. Wullschleger, Stan D. Thornton, Peter E. Xu, Xiaofeng 2021-10-27 application/pdf http://www.osti.gov/servlets/purl/1582360 https://www.osti.gov/biblio/1582360 https://doi.org/10.1029/2019ms001771 unknown http://www.osti.gov/servlets/purl/1582360 https://www.osti.gov/biblio/1582360 https://doi.org/10.1029/2019ms001771 doi:10.1029/2019ms001771 54 ENVIRONMENTAL SCIENCES 2021 ftosti https://doi.org/10.1029/2019ms001771 2023-07-11T09:38:53Z Spatial heterogeneities in soil hydrology have been confirmed as a key control on CO 2 and CH 4 fluxes in the Arctic tundra ecosystem. In this study, we applied a mechanistic ecosystem model, CLM-Microbe, to examine the microtopographic impacts on CO 2 and CH 4 fluxes across seven landscape types in Utqiaġvik, Alaska: trough, low-centered polygon (LCP) center, LCP transition, LCP rim, high-centered polygon (HCP) center, HCP transition, and HCP rim. We first validated the CLM-Microbe model against static-chamber measured CO 2 and CH 4 fluxes in 2013 for three landscape types: trough, LCP center, and LCP rim. Model application showed that low-elevation and thus wetter landscape types (i.e., trough, transitions, and LCP center) had larger CH 4 emissions rates with greater seasonal variations than high-elevation and drier landscape types (rims and HCP center). Sensitivity analysis indicated that substrate availability for methanogenesis (acetate, CO 2 + H 2 ) is the most important factor determining CH 4 emission, and vegetation physiological properties largely affect the net ecosystem carbon exchange and ecosystem respiration in Arctic tundra ecosystems. Modeled CH 4 emissions for different microtopographic features were upscaled to the eddy covariance (EC) domain with an area-weighted approach before validation against EC-measured CH 4 fluxes. The model underestimated the EC-measured CH 4 flux by 20% and 25% at daily and hourly time steps, suggesting the importance of the time step in reporting CH 4 flux. The strong microtopographic impacts on CO 2 and CH 4 fluxes call for a model-data integration framework for better understanding and predicting carbon flux in the highly heterogeneous Arctic landscape. Other/Unknown Material Arctic Tundra Alaska SciTec Connect (Office of Scientific and Technical Information - OSTI, U.S. Department of Energy) Arctic Journal of Advances in Modeling Earth Systems 11 12 4288 4304 |
institution |
Open Polar |
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SciTec Connect (Office of Scientific and Technical Information - OSTI, U.S. Department of Energy) |
op_collection_id |
ftosti |
language |
unknown |
topic |
54 ENVIRONMENTAL SCIENCES |
spellingShingle |
54 ENVIRONMENTAL SCIENCES Wang, Yihui Yuan, Fengming Yuan, Fenghui Gu, Baohua Hahn, Melanie S. Torn, Margaret S. Ricciuto, Daniel M. Kumar, Jitendra He, Liyuan Zona, Donatella Lipson, David A. Wagner, Robert Oechel, Walter C. Wullschleger, Stan D. Thornton, Peter E. Xu, Xiaofeng Mechanistic Modeling of Microtopographic Impacts on CO 2 and CH 4 Fluxes in an Alaskan Tundra Ecosystem Using the CLM-Microbe Model |
topic_facet |
54 ENVIRONMENTAL SCIENCES |
description |
Spatial heterogeneities in soil hydrology have been confirmed as a key control on CO 2 and CH 4 fluxes in the Arctic tundra ecosystem. In this study, we applied a mechanistic ecosystem model, CLM-Microbe, to examine the microtopographic impacts on CO 2 and CH 4 fluxes across seven landscape types in Utqiaġvik, Alaska: trough, low-centered polygon (LCP) center, LCP transition, LCP rim, high-centered polygon (HCP) center, HCP transition, and HCP rim. We first validated the CLM-Microbe model against static-chamber measured CO 2 and CH 4 fluxes in 2013 for three landscape types: trough, LCP center, and LCP rim. Model application showed that low-elevation and thus wetter landscape types (i.e., trough, transitions, and LCP center) had larger CH 4 emissions rates with greater seasonal variations than high-elevation and drier landscape types (rims and HCP center). Sensitivity analysis indicated that substrate availability for methanogenesis (acetate, CO 2 + H 2 ) is the most important factor determining CH 4 emission, and vegetation physiological properties largely affect the net ecosystem carbon exchange and ecosystem respiration in Arctic tundra ecosystems. Modeled CH 4 emissions for different microtopographic features were upscaled to the eddy covariance (EC) domain with an area-weighted approach before validation against EC-measured CH 4 fluxes. The model underestimated the EC-measured CH 4 flux by 20% and 25% at daily and hourly time steps, suggesting the importance of the time step in reporting CH 4 flux. The strong microtopographic impacts on CO 2 and CH 4 fluxes call for a model-data integration framework for better understanding and predicting carbon flux in the highly heterogeneous Arctic landscape. |
author |
Wang, Yihui Yuan, Fengming Yuan, Fenghui Gu, Baohua Hahn, Melanie S. Torn, Margaret S. Ricciuto, Daniel M. Kumar, Jitendra He, Liyuan Zona, Donatella Lipson, David A. Wagner, Robert Oechel, Walter C. Wullschleger, Stan D. Thornton, Peter E. Xu, Xiaofeng |
author_facet |
Wang, Yihui Yuan, Fengming Yuan, Fenghui Gu, Baohua Hahn, Melanie S. Torn, Margaret S. Ricciuto, Daniel M. Kumar, Jitendra He, Liyuan Zona, Donatella Lipson, David A. Wagner, Robert Oechel, Walter C. Wullschleger, Stan D. Thornton, Peter E. Xu, Xiaofeng |
author_sort |
Wang, Yihui |
title |
Mechanistic Modeling of Microtopographic Impacts on CO 2 and CH 4 Fluxes in an Alaskan Tundra Ecosystem Using the CLM-Microbe Model |
title_short |
Mechanistic Modeling of Microtopographic Impacts on CO 2 and CH 4 Fluxes in an Alaskan Tundra Ecosystem Using the CLM-Microbe Model |
title_full |
Mechanistic Modeling of Microtopographic Impacts on CO 2 and CH 4 Fluxes in an Alaskan Tundra Ecosystem Using the CLM-Microbe Model |
title_fullStr |
Mechanistic Modeling of Microtopographic Impacts on CO 2 and CH 4 Fluxes in an Alaskan Tundra Ecosystem Using the CLM-Microbe Model |
title_full_unstemmed |
Mechanistic Modeling of Microtopographic Impacts on CO 2 and CH 4 Fluxes in an Alaskan Tundra Ecosystem Using the CLM-Microbe Model |
title_sort |
mechanistic modeling of microtopographic impacts on co 2 and ch 4 fluxes in an alaskan tundra ecosystem using the clm-microbe model |
publishDate |
2021 |
url |
http://www.osti.gov/servlets/purl/1582360 https://www.osti.gov/biblio/1582360 https://doi.org/10.1029/2019ms001771 |
geographic |
Arctic |
geographic_facet |
Arctic |
genre |
Arctic Tundra Alaska |
genre_facet |
Arctic Tundra Alaska |
op_relation |
http://www.osti.gov/servlets/purl/1582360 https://www.osti.gov/biblio/1582360 https://doi.org/10.1029/2019ms001771 doi:10.1029/2019ms001771 |
op_doi |
https://doi.org/10.1029/2019ms001771 |
container_title |
Journal of Advances in Modeling Earth Systems |
container_volume |
11 |
container_issue |
12 |
container_start_page |
4288 |
op_container_end_page |
4304 |
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1772812096304578560 |