Estimating regional-scale methane flux and budgets using CARVE aircraft measurements over Alaska
Methane (CH 4 ) is the second most important greenhouse gas but its emissions from northern regions are still poorly constrained. In this study, we analyze a subset of in situ CH 4 aircraft observations made over Alaska during the growing seasons of 2012–2014 as part of the Carbon in Arctic Reservoi...
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Online Access: | https://doi.org/10.5194/acp-18-185-2018 https://www.atmos-chem-phys.net/18/185/2018/ |
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ftcopernicus:oai:publications.copernicus.org:acp57051 2023-05-15T15:12:19+02:00 Estimating regional-scale methane flux and budgets using CARVE aircraft measurements over Alaska Hartery, Sean Commane, Róisín Lindaas, Jakob Sweeney, Colm Henderson, John Mountain, Marikate Steiner, Nicholas McDonald, Kyle Dinardo, Steven J. Miller, Charles E. Wofsy, Steven C. Chang, Rachel Y.-W. 2018-09-20 application/pdf https://doi.org/10.5194/acp-18-185-2018 https://www.atmos-chem-phys.net/18/185/2018/ eng eng doi:10.5194/acp-18-185-2018 https://www.atmos-chem-phys.net/18/185/2018/ eISSN: 1680-7324 Text 2018 ftcopernicus https://doi.org/10.5194/acp-18-185-2018 2019-12-24T09:50:45Z Methane (CH 4 ) is the second most important greenhouse gas but its emissions from northern regions are still poorly constrained. In this study, we analyze a subset of in situ CH 4 aircraft observations made over Alaska during the growing seasons of 2012–2014 as part of the Carbon in Arctic Reservoirs Vulnerability Experiment (CARVE). Net surface CH 4 fluxes are estimated using a Lagrangian particle dispersion model which quantitatively links surface emissions from Alaska and the western Yukon with observations of enhanced CH 4 in the mixed layer. We estimate that between May and September, net CH 4 emissions from the region of interest were 2.2 ± 0.5 Tg, 1.9 ± 0.4 Tg, and 2.3 ± 0.6 Tg of CH 4 for 2012, 2013, and 2014, respectively. If emissions are only attributed to two biogenic eco-regions within our domain, then tundra regions were the predominant source, accounting for over half of the overall budget despite only representing 18 % of the total surface area. Boreal regions, which cover a large part of the study region, accounted for the remainder of the emissions. Simple multiple linear regression analysis revealed that, overall, CH 4 fluxes were largely driven by soil temperature and elevation. In regions specifically dominated by wetlands, soil temperature and moisture at 10 cm depth were important explanatory variables while in regions that were not wetlands, soil temperature and moisture at 40 cm depth were more important, suggesting deeper methanogenesis in drier soils. Although similar environmental drivers have been found in the past to control CH 4 emissions at local scales, this study shows that they can be used to generate a statistical model to estimate the regional-scale net CH 4 budget. Text Arctic Tundra Alaska Yukon Copernicus Publications: E-Journals Arctic Yukon Atmospheric Chemistry and Physics 18 1 185 202 |
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Copernicus Publications: E-Journals |
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ftcopernicus |
language |
English |
description |
Methane (CH 4 ) is the second most important greenhouse gas but its emissions from northern regions are still poorly constrained. In this study, we analyze a subset of in situ CH 4 aircraft observations made over Alaska during the growing seasons of 2012–2014 as part of the Carbon in Arctic Reservoirs Vulnerability Experiment (CARVE). Net surface CH 4 fluxes are estimated using a Lagrangian particle dispersion model which quantitatively links surface emissions from Alaska and the western Yukon with observations of enhanced CH 4 in the mixed layer. We estimate that between May and September, net CH 4 emissions from the region of interest were 2.2 ± 0.5 Tg, 1.9 ± 0.4 Tg, and 2.3 ± 0.6 Tg of CH 4 for 2012, 2013, and 2014, respectively. If emissions are only attributed to two biogenic eco-regions within our domain, then tundra regions were the predominant source, accounting for over half of the overall budget despite only representing 18 % of the total surface area. Boreal regions, which cover a large part of the study region, accounted for the remainder of the emissions. Simple multiple linear regression analysis revealed that, overall, CH 4 fluxes were largely driven by soil temperature and elevation. In regions specifically dominated by wetlands, soil temperature and moisture at 10 cm depth were important explanatory variables while in regions that were not wetlands, soil temperature and moisture at 40 cm depth were more important, suggesting deeper methanogenesis in drier soils. Although similar environmental drivers have been found in the past to control CH 4 emissions at local scales, this study shows that they can be used to generate a statistical model to estimate the regional-scale net CH 4 budget. |
format |
Text |
author |
Hartery, Sean Commane, Róisín Lindaas, Jakob Sweeney, Colm Henderson, John Mountain, Marikate Steiner, Nicholas McDonald, Kyle Dinardo, Steven J. Miller, Charles E. Wofsy, Steven C. Chang, Rachel Y.-W. |
spellingShingle |
Hartery, Sean Commane, Róisín Lindaas, Jakob Sweeney, Colm Henderson, John Mountain, Marikate Steiner, Nicholas McDonald, Kyle Dinardo, Steven J. Miller, Charles E. Wofsy, Steven C. Chang, Rachel Y.-W. Estimating regional-scale methane flux and budgets using CARVE aircraft measurements over Alaska |
author_facet |
Hartery, Sean Commane, Róisín Lindaas, Jakob Sweeney, Colm Henderson, John Mountain, Marikate Steiner, Nicholas McDonald, Kyle Dinardo, Steven J. Miller, Charles E. Wofsy, Steven C. Chang, Rachel Y.-W. |
author_sort |
Hartery, Sean |
title |
Estimating regional-scale methane flux and budgets using CARVE aircraft measurements over Alaska |
title_short |
Estimating regional-scale methane flux and budgets using CARVE aircraft measurements over Alaska |
title_full |
Estimating regional-scale methane flux and budgets using CARVE aircraft measurements over Alaska |
title_fullStr |
Estimating regional-scale methane flux and budgets using CARVE aircraft measurements over Alaska |
title_full_unstemmed |
Estimating regional-scale methane flux and budgets using CARVE aircraft measurements over Alaska |
title_sort |
estimating regional-scale methane flux and budgets using carve aircraft measurements over alaska |
publishDate |
2018 |
url |
https://doi.org/10.5194/acp-18-185-2018 https://www.atmos-chem-phys.net/18/185/2018/ |
geographic |
Arctic Yukon |
geographic_facet |
Arctic Yukon |
genre |
Arctic Tundra Alaska Yukon |
genre_facet |
Arctic Tundra Alaska Yukon |
op_source |
eISSN: 1680-7324 |
op_relation |
doi:10.5194/acp-18-185-2018 https://www.atmos-chem-phys.net/18/185/2018/ |
op_doi |
https://doi.org/10.5194/acp-18-185-2018 |
container_title |
Atmospheric Chemistry and Physics |
container_volume |
18 |
container_issue |
1 |
container_start_page |
185 |
op_container_end_page |
202 |
_version_ |
1766343019925078016 |