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dc.contributor.authorPohlman, John
dc.contributor.authorGreinert, Jens
dc.contributor.authorRuppel, Carolyn
dc.contributor.authorSilyakova, Anna
dc.contributor.authorVielstädte, Lisa
dc.contributor.authorCasso, Michael
dc.contributor.authorMienert, Jürgen
dc.contributor.authorBünz, Stefan
dc.date.accessioned2018-06-28T12:26:03Z
dc.date.available2018-06-28T12:26:03Z
dc.date.issued2017-05-08
dc.description.abstractContinued warming of the Arctic Ocean in coming decades is projected to trigger the release of teragrams (1 Tg = 106 tons) of methane from thawing subsea permafrost on shallow continental shelves and dissociation of methane hydrate on upper continental slopes. On the shallow shelves (<100 m water depth), methane released from the seafloor may reach the atmosphere and potentially amplify global warming. On the other hand, biological uptake of carbon dioxide (CO2) has the potential to offset the positive warming potential of emitted methane, a process that has not received detailed consideration for these settings. Continuous sea−air gas flux data collected over a shallow ebullitive methane seep field on the Svalbard margin reveal atmospheric CO2 uptake rates (−33,300 ± 7,900 μmol m−2⋅d−1) twice that of surrounding waters and ∼1,900 times greater than the diffusive sea−air methane efflux (17.3 ± 4.8 μmol m−2⋅d−1). The negative radiative forcing expected from this CO2 uptake is up to 231 times greater than the positive radiative forcing from the methane emissions. Surface water characteristics (e.g., high dissolved oxygen, high pH, and enrichment of 13C in CO2) indicate that upwelling of cold, nutrient-rich water from near the seafloor accompanies methane emissions and stimulates CO2 consumption by photosynthesizing phytoplankton. These findings challenge the widely held perception that areas characterized by shallow-water methane seeps and/or strongly elevated sea−air methane flux always increase the global atmospheric greenhouse gas burden.en_US
dc.description.sponsorshipUSGS US Department of Energy UiT The Arctic University of Norwayen_US
dc.descriptionSource at <a href=https://doi.org/10.1073/pnas.1618926114> https://doi.org/10.1073/pnas.1618926114</a>.en_US
dc.identifier.citationPohlman, J., Greinert, J., Ruppel, C., Silyakova, A., Vielstädte, L, Casso, M., ... Bünz, S. (2017). Enhanced CO2 uptake at a shallow Arctic Ocean seep field overwhelms the positive warming potential of emitted methane. Proceedings of the National Academy of Sciences of the United States of America, 114(21), 5355-5360. https://doi.org/10.1073/pnas.1618926114en_US
dc.identifier.cristinIDFRIDAID 1470158
dc.identifier.doi10.1073/pnas.1618926114
dc.identifier.issn0027-8424
dc.identifier.issn1091-6490
dc.identifier.urihttps://hdl.handle.net/10037/13047
dc.language.isoengen_US
dc.publisherNational Academy of Sciencesen_US
dc.relation.journalProceedings of the National Academy of Sciences of the United States of America
dc.relation.projectIDinfo:eu-repo/grantAgreement/RCN/SFF/223259/Norway/Centre for Arctic Gas Hydrate, Environment and Climate/CAGE/en_US
dc.rights.accessRightsopenAccessen_US
dc.subjectVDP::Matematikk og Naturvitenskap: 400::Geofag: 450en_US
dc.subjectVDP::Mathematics and natural science: 400::Geosciences: 450en_US
dc.subjectmethaneen_US
dc.subjectcarbon dioxideen_US
dc.subjectgreenhouse gas emissionsen_US
dc.subjectmarine biogeochemistryen_US
dc.subjectArctic Oceanen_US
dc.titleEnhanced CO2 uptake at a shallow Arctic Ocean seep field overwhelms the positive warming potential of emitted methaneen_US
dc.typeJournal articleen_US
dc.typeTidsskriftartikkelen_US
dc.typePeer revieweden_US


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