Autonomous methane seep site monitoring offshore western Svalbard: hourly to seasonal variability and associated oceanographic parameters
Improved quantification techniques of natural sources are needed to explain variations in atmospheric methane. In polar regions, high uncertainties in current estimates of methane release from the seabed remain. We present unique 10- and 3-month time series of bottom water measurements of physical a...
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Copernicus Publications
2022
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Online Access: | https://doi.org/10.5194/os-18-233-2022 https://noa.gwlb.de/receive/cop_mods_00060208 https://noa.gwlb.de/servlets/MCRFileNodeServlet/cop_derivate_00059855/os-18-233-2022.pdf https://os.copernicus.org/articles/18/233/2022/os-18-233-2022.pdf |
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ftnonlinearchiv:oai:noa.gwlb.de:cop_mods_00060208 2023-05-15T18:29:44+02:00 Autonomous methane seep site monitoring offshore western Svalbard: hourly to seasonal variability and associated oceanographic parameters Dølven, Knut Ola Ferré, Bénédicte Silyakova, Anna Jansson, Pär Linke, Peter Moser, Manuel 2022-02 electronic https://doi.org/10.5194/os-18-233-2022 https://noa.gwlb.de/receive/cop_mods_00060208 https://noa.gwlb.de/servlets/MCRFileNodeServlet/cop_derivate_00059855/os-18-233-2022.pdf https://os.copernicus.org/articles/18/233/2022/os-18-233-2022.pdf eng eng Copernicus Publications Ocean Science -- http://www.bibliothek.uni-regensburg.de/ezeit/?2183769 -- http://www.copernicus.org/EGU/os/os.html -- 1812-0792 https://doi.org/10.5194/os-18-233-2022 https://noa.gwlb.de/receive/cop_mods_00060208 https://noa.gwlb.de/servlets/MCRFileNodeServlet/cop_derivate_00059855/os-18-233-2022.pdf https://os.copernicus.org/articles/18/233/2022/os-18-233-2022.pdf https://creativecommons.org/licenses/by/4.0/ uneingeschränkt info:eu-repo/semantics/openAccess CC-BY article Verlagsveröffentlichung article Text doc-type:article 2022 ftnonlinearchiv https://doi.org/10.5194/os-18-233-2022 2022-02-21T00:10:06Z Improved quantification techniques of natural sources are needed to explain variations in atmospheric methane. In polar regions, high uncertainties in current estimates of methane release from the seabed remain. We present unique 10- and 3-month time series of bottom water measurements of physical and chemical parameters from two autonomous ocean observatories deployed at separate intense seabed methane seep sites (91 and 246 m depth) offshore western Svalbard from 2015 to 2016. Results show high short-term (100–1000 nmol L−1 within hours) and seasonal variation, as well as higher (2–7 times) methane concentrations compared to previous measurements. Rapid variability is explained by uneven distribution of seepage and changing ocean current directions. No overt influence of tidal hydrostatic pressure or water temperature variations on methane concentration was observed, but an observed negative correlation with temperature at the 246 m site fits with hypothesized seasonal blocking of lateral methane pathways in the sediments. Negative correlation between bottom water methane concentration (and variability) and wind forcing, concomitant with signs of weaker water column stratification, indicates increased potential for methane release to the atmosphere in fall and winter. We present new information about short- and long-term methane variability and provide a preliminary constraint on the uncertainties that arise in methane inventory estimates from this variability. Article in Journal/Newspaper Svalbard Niedersächsisches Online-Archiv NOA Svalbard Ocean Science 18 1 233 254 |
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Open Polar |
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Niedersächsisches Online-Archiv NOA |
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ftnonlinearchiv |
language |
English |
topic |
article Verlagsveröffentlichung |
spellingShingle |
article Verlagsveröffentlichung Dølven, Knut Ola Ferré, Bénédicte Silyakova, Anna Jansson, Pär Linke, Peter Moser, Manuel Autonomous methane seep site monitoring offshore western Svalbard: hourly to seasonal variability and associated oceanographic parameters |
topic_facet |
article Verlagsveröffentlichung |
description |
Improved quantification techniques of natural sources are needed to explain variations in atmospheric methane. In polar regions, high uncertainties in current estimates of methane release from the seabed remain. We present unique 10- and 3-month time series of bottom water measurements of physical and chemical parameters from two autonomous ocean observatories deployed at separate intense seabed methane seep sites (91 and 246 m depth) offshore western Svalbard from 2015 to 2016. Results show high short-term (100–1000 nmol L−1 within hours) and seasonal variation, as well as higher (2–7 times) methane concentrations compared to previous measurements. Rapid variability is explained by uneven distribution of seepage and changing ocean current directions. No overt influence of tidal hydrostatic pressure or water temperature variations on methane concentration was observed, but an observed negative correlation with temperature at the 246 m site fits with hypothesized seasonal blocking of lateral methane pathways in the sediments. Negative correlation between bottom water methane concentration (and variability) and wind forcing, concomitant with signs of weaker water column stratification, indicates increased potential for methane release to the atmosphere in fall and winter. We present new information about short- and long-term methane variability and provide a preliminary constraint on the uncertainties that arise in methane inventory estimates from this variability. |
format |
Article in Journal/Newspaper |
author |
Dølven, Knut Ola Ferré, Bénédicte Silyakova, Anna Jansson, Pär Linke, Peter Moser, Manuel |
author_facet |
Dølven, Knut Ola Ferré, Bénédicte Silyakova, Anna Jansson, Pär Linke, Peter Moser, Manuel |
author_sort |
Dølven, Knut Ola |
title |
Autonomous methane seep site monitoring offshore western Svalbard: hourly to seasonal variability and associated oceanographic parameters |
title_short |
Autonomous methane seep site monitoring offshore western Svalbard: hourly to seasonal variability and associated oceanographic parameters |
title_full |
Autonomous methane seep site monitoring offshore western Svalbard: hourly to seasonal variability and associated oceanographic parameters |
title_fullStr |
Autonomous methane seep site monitoring offshore western Svalbard: hourly to seasonal variability and associated oceanographic parameters |
title_full_unstemmed |
Autonomous methane seep site monitoring offshore western Svalbard: hourly to seasonal variability and associated oceanographic parameters |
title_sort |
autonomous methane seep site monitoring offshore western svalbard: hourly to seasonal variability and associated oceanographic parameters |
publisher |
Copernicus Publications |
publishDate |
2022 |
url |
https://doi.org/10.5194/os-18-233-2022 https://noa.gwlb.de/receive/cop_mods_00060208 https://noa.gwlb.de/servlets/MCRFileNodeServlet/cop_derivate_00059855/os-18-233-2022.pdf https://os.copernicus.org/articles/18/233/2022/os-18-233-2022.pdf |
geographic |
Svalbard |
geographic_facet |
Svalbard |
genre |
Svalbard |
genre_facet |
Svalbard |
op_relation |
Ocean Science -- http://www.bibliothek.uni-regensburg.de/ezeit/?2183769 -- http://www.copernicus.org/EGU/os/os.html -- 1812-0792 https://doi.org/10.5194/os-18-233-2022 https://noa.gwlb.de/receive/cop_mods_00060208 https://noa.gwlb.de/servlets/MCRFileNodeServlet/cop_derivate_00059855/os-18-233-2022.pdf https://os.copernicus.org/articles/18/233/2022/os-18-233-2022.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/os-18-233-2022 |
container_title |
Ocean Science |
container_volume |
18 |
container_issue |
1 |
container_start_page |
233 |
op_container_end_page |
254 |
_version_ |
1766213067330289664 |