Assessing the potential for non-turbulent methane escape from the East Siberian Arctic Shelf
The East Siberian Arctic Shelf (ESAS) hosts large yet poorly quantified reservoirs of subsea permafrost and associated gas hydrates. It has been suggested that the global-warming induced thawing and dissociation of these reservoirs is currently releasing methane (CH4) to the shallow coastal ocean an...
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Copernicus Publications
2020
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ftnonlinearchiv:oai:noa.gwlb.de:cop_mods_00051880 2023-05-15T14:58:09+02:00 Assessing the potential for non-turbulent methane escape from the East Siberian Arctic Shelf Puglini, Matteo Brovkin, Victor Regnier, Pierre Arndt, Sandra 2020-06 electronic https://doi.org/10.5194/bg-17-3247-2020 https://noa.gwlb.de/receive/cop_mods_00051880 https://noa.gwlb.de/servlets/MCRFileNodeServlet/cop_derivate_00051536/bg-17-3247-2020.pdf https://bg.copernicus.org/articles/17/3247/2020/bg-17-3247-2020.pdf eng eng Copernicus Publications Biogeosciences -- http://www.bibliothek.uni-regensburg.de/ezeit/?2158181 -- http://www.copernicus.org/EGU/bg/bg.html -- 1726-4189 https://doi.org/10.5194/bg-17-3247-2020 https://noa.gwlb.de/receive/cop_mods_00051880 https://noa.gwlb.de/servlets/MCRFileNodeServlet/cop_derivate_00051536/bg-17-3247-2020.pdf https://bg.copernicus.org/articles/17/3247/2020/bg-17-3247-2020.pdf https://creativecommons.org/licenses/by/4.0/ uneingeschränkt info:eu-repo/semantics/openAccess CC-BY article Verlagsveröffentlichung article Text doc-type:article 2020 ftnonlinearchiv https://doi.org/10.5194/bg-17-3247-2020 2022-02-08T22:36:13Z The East Siberian Arctic Shelf (ESAS) hosts large yet poorly quantified reservoirs of subsea permafrost and associated gas hydrates. It has been suggested that the global-warming induced thawing and dissociation of these reservoirs is currently releasing methane (CH4) to the shallow coastal ocean and ultimately the atmosphere. However, a major unknown in assessing the contribution of this CH4 flux to the global CH4 cycle and its climate feedbacks is the fate of CH4 as it migrates towards the sediment–water interface. In marine sediments, (an)aerobic oxidation reactions generally act as a very efficient methane sink. However, a number of environmental conditions can reduce the efficiency of this biofilter. Here, we used a reaction-transport model to assess the efficiency of the benthic methane filter and, thus, the potential for benthic methane escape across a wide range of environmental conditions that could be encountered on the East Siberian Arctic Shelf. Results show that, under steady-state conditions, anaerobic oxidation of methane (AOM) acts as an efficient biofilter. However, high CH4 escape is simulated for rapidly accumulating and/or active sediments and can be further enhanced by the presence of organic matter with intermediate reactivity and/or intense local transport processes, such as bioirrigation. In addition, in active settings, the sudden onset of CH4 flux triggered by, for instance, permafrost thaw or hydrate destabilization can also drive a high non-turbulent methane escape of up to 19 µmol CH4 cm−2 yr−1 during a transient, multi-decadal period. This “window of opportunity” arises due to delayed response of the resident microbial community to suddenly changing CH4 fluxes. A first-order estimate of non-turbulent, benthic methane efflux from the Laptev Sea is derived as well. We find that, under present-day conditions, non-turbulent methane efflux from Laptev Sea sediments does not exceed 1 Gg CH4 yr−1. As a consequence, we conclude that previously published estimates of ocean–atmosphere CH4 fluxes from the ESAS cannot be supported by non-turbulent, benthic methane escape. Article in Journal/Newspaper Arctic Global warming laptev Laptev Sea permafrost Niedersächsisches Online-Archiv NOA Arctic Laptev Sea Biogeosciences 17 12 3247 3275 |
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Niedersächsisches Online-Archiv NOA |
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English |
topic |
article Verlagsveröffentlichung |
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article Verlagsveröffentlichung Puglini, Matteo Brovkin, Victor Regnier, Pierre Arndt, Sandra Assessing the potential for non-turbulent methane escape from the East Siberian Arctic Shelf |
topic_facet |
article Verlagsveröffentlichung |
description |
The East Siberian Arctic Shelf (ESAS) hosts large yet poorly quantified reservoirs of subsea permafrost and associated gas hydrates. It has been suggested that the global-warming induced thawing and dissociation of these reservoirs is currently releasing methane (CH4) to the shallow coastal ocean and ultimately the atmosphere. However, a major unknown in assessing the contribution of this CH4 flux to the global CH4 cycle and its climate feedbacks is the fate of CH4 as it migrates towards the sediment–water interface. In marine sediments, (an)aerobic oxidation reactions generally act as a very efficient methane sink. However, a number of environmental conditions can reduce the efficiency of this biofilter. Here, we used a reaction-transport model to assess the efficiency of the benthic methane filter and, thus, the potential for benthic methane escape across a wide range of environmental conditions that could be encountered on the East Siberian Arctic Shelf. Results show that, under steady-state conditions, anaerobic oxidation of methane (AOM) acts as an efficient biofilter. However, high CH4 escape is simulated for rapidly accumulating and/or active sediments and can be further enhanced by the presence of organic matter with intermediate reactivity and/or intense local transport processes, such as bioirrigation. In addition, in active settings, the sudden onset of CH4 flux triggered by, for instance, permafrost thaw or hydrate destabilization can also drive a high non-turbulent methane escape of up to 19 µmol CH4 cm−2 yr−1 during a transient, multi-decadal period. This “window of opportunity” arises due to delayed response of the resident microbial community to suddenly changing CH4 fluxes. A first-order estimate of non-turbulent, benthic methane efflux from the Laptev Sea is derived as well. We find that, under present-day conditions, non-turbulent methane efflux from Laptev Sea sediments does not exceed 1 Gg CH4 yr−1. As a consequence, we conclude that previously published estimates of ocean–atmosphere CH4 fluxes from the ESAS cannot be supported by non-turbulent, benthic methane escape. |
format |
Article in Journal/Newspaper |
author |
Puglini, Matteo Brovkin, Victor Regnier, Pierre Arndt, Sandra |
author_facet |
Puglini, Matteo Brovkin, Victor Regnier, Pierre Arndt, Sandra |
author_sort |
Puglini, Matteo |
title |
Assessing the potential for non-turbulent methane escape from the East Siberian Arctic Shelf |
title_short |
Assessing the potential for non-turbulent methane escape from the East Siberian Arctic Shelf |
title_full |
Assessing the potential for non-turbulent methane escape from the East Siberian Arctic Shelf |
title_fullStr |
Assessing the potential for non-turbulent methane escape from the East Siberian Arctic Shelf |
title_full_unstemmed |
Assessing the potential for non-turbulent methane escape from the East Siberian Arctic Shelf |
title_sort |
assessing the potential for non-turbulent methane escape from the east siberian arctic shelf |
publisher |
Copernicus Publications |
publishDate |
2020 |
url |
https://doi.org/10.5194/bg-17-3247-2020 https://noa.gwlb.de/receive/cop_mods_00051880 https://noa.gwlb.de/servlets/MCRFileNodeServlet/cop_derivate_00051536/bg-17-3247-2020.pdf https://bg.copernicus.org/articles/17/3247/2020/bg-17-3247-2020.pdf |
geographic |
Arctic Laptev Sea |
geographic_facet |
Arctic Laptev Sea |
genre |
Arctic Global warming laptev Laptev Sea permafrost |
genre_facet |
Arctic Global warming laptev Laptev Sea permafrost |
op_relation |
Biogeosciences -- http://www.bibliothek.uni-regensburg.de/ezeit/?2158181 -- http://www.copernicus.org/EGU/bg/bg.html -- 1726-4189 https://doi.org/10.5194/bg-17-3247-2020 https://noa.gwlb.de/receive/cop_mods_00051880 https://noa.gwlb.de/servlets/MCRFileNodeServlet/cop_derivate_00051536/bg-17-3247-2020.pdf https://bg.copernicus.org/articles/17/3247/2020/bg-17-3247-2020.pdf |
op_rights |
https://creativecommons.org/licenses/by/4.0/ uneingeschränkt info:eu-repo/semantics/openAccess |
op_rightsnorm |
CC-BY |
op_doi |
https://doi.org/10.5194/bg-17-3247-2020 |
container_title |
Biogeosciences |
container_volume |
17 |
container_issue |
12 |
container_start_page |
3247 |
op_container_end_page |
3275 |
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1766330240048562176 |