Carbon Emissions From the Edge of the Greenland Ice Sheet Reveal Subglacial Processes of Methane and Carbon Dioxide Turnover
Direct gaseous emissions of methane (CH4) and carbon dioxide (CO2) from the subglacial environment under Greenland Ice Sheet (GrIS) were only recently discovered and it is yet to be determined how important it is for the panarctic carbon budget. We measured in situ net gaseous emissions of subglacia...
Main Authors: | , , , , |
---|---|
Format: | Article in Journal/Newspaper |
Language: | English |
Published: |
2021
|
Subjects: | |
Online Access: | http://hdl.handle.net/2013/ULB-DIPOT:oai:dipot.ulb.ac.be:2013/336749 |
id |
ftunivbruxelles:oai:dipot.ulb.ac.be:2013/336749 |
---|---|
record_format |
openpolar |
spelling |
ftunivbruxelles:oai:dipot.ulb.ac.be:2013/336749 2023-05-15T16:28:19+02:00 Carbon Emissions From the Edge of the Greenland Ice Sheet Reveal Subglacial Processes of Methane and Carbon Dioxide Turnover Christiansen, Jesper Riis Röckmann, Thomas Popa, M.E. Sapart, Célia Jørgensen, Christian Juncher 2021-11 No full-text files http://hdl.handle.net/2013/ULB-DIPOT:oai:dipot.ulb.ac.be:2013/336749 en eng uri/info:doi/10.1029/2021JG006308 uri/info:scp/85119837541 http://hdl.handle.net/2013/ULB-DIPOT:oai:dipot.ulb.ac.be:2013/336749 Journal of Geophysical Research. Biogeosciences, 126 (11 Généralités info:eu-repo/semantics/article info:ulb-repo/semantics/articlePeerReview info:ulb-repo/semantics/openurl/article 2021 ftunivbruxelles 2022-06-29T22:19:49Z Direct gaseous emissions of methane (CH4) and carbon dioxide (CO2) from the subglacial environment under Greenland Ice Sheet (GrIS) were only recently discovered and it is yet to be determined how important it is for the panarctic carbon budget. We measured in situ net gaseous emissions of subglacial CH4 and CO2, dissolved concentrations and isotopic composition of gases (13C and 2H) at the onset, near maximum, and at the end of the melt season in 2018 and 2019. We found a tight relation between gaseous and dissolved CH4 and CO2, respectively, indicating that degassing from the subglacial meltwater is the main source of these gases in the subglacial air. The diurnal variability of in situ mole fractions of CH4 and CO2 in subglacial air was related to meltwater runoff showing that the net emission magnitude is directly related to glacial hydrology. We observed that maximum in situ mole fractions of CH4 and CO2 appeared at the onset of the melt season and decreased over the melt season. The isotopic signature of CH4 in the subglacial air indicated that it likely originated from microbial methanogenesis which remained constant during the season. Isotopic signatures of subglacial CO2 indicate mixed sources from microbial oxidation of CH4, remineralization of sedimentary organic carbon, and possibly influenced by removal of CO2 by weathering. Our study indicate large emissions of both CO2 and CH4, but continuous studies over entire melt seasons are needed to determine the origin and emission magnitudes and their relation to the glacial dynamics. SCOPUS: ar.j DecretOANoAutActif info:eu-repo/semantics/published Article in Journal/Newspaper Greenland Ice Sheet DI-fusion : dépôt institutionnel de l'Université libre de Bruxelles (ULB) Greenland |
institution |
Open Polar |
collection |
DI-fusion : dépôt institutionnel de l'Université libre de Bruxelles (ULB) |
op_collection_id |
ftunivbruxelles |
language |
English |
topic |
Généralités |
spellingShingle |
Généralités Christiansen, Jesper Riis Röckmann, Thomas Popa, M.E. Sapart, Célia Jørgensen, Christian Juncher Carbon Emissions From the Edge of the Greenland Ice Sheet Reveal Subglacial Processes of Methane and Carbon Dioxide Turnover |
topic_facet |
Généralités |
description |
Direct gaseous emissions of methane (CH4) and carbon dioxide (CO2) from the subglacial environment under Greenland Ice Sheet (GrIS) were only recently discovered and it is yet to be determined how important it is for the panarctic carbon budget. We measured in situ net gaseous emissions of subglacial CH4 and CO2, dissolved concentrations and isotopic composition of gases (13C and 2H) at the onset, near maximum, and at the end of the melt season in 2018 and 2019. We found a tight relation between gaseous and dissolved CH4 and CO2, respectively, indicating that degassing from the subglacial meltwater is the main source of these gases in the subglacial air. The diurnal variability of in situ mole fractions of CH4 and CO2 in subglacial air was related to meltwater runoff showing that the net emission magnitude is directly related to glacial hydrology. We observed that maximum in situ mole fractions of CH4 and CO2 appeared at the onset of the melt season and decreased over the melt season. The isotopic signature of CH4 in the subglacial air indicated that it likely originated from microbial methanogenesis which remained constant during the season. Isotopic signatures of subglacial CO2 indicate mixed sources from microbial oxidation of CH4, remineralization of sedimentary organic carbon, and possibly influenced by removal of CO2 by weathering. Our study indicate large emissions of both CO2 and CH4, but continuous studies over entire melt seasons are needed to determine the origin and emission magnitudes and their relation to the glacial dynamics. SCOPUS: ar.j DecretOANoAutActif info:eu-repo/semantics/published |
format |
Article in Journal/Newspaper |
author |
Christiansen, Jesper Riis Röckmann, Thomas Popa, M.E. Sapart, Célia Jørgensen, Christian Juncher |
author_facet |
Christiansen, Jesper Riis Röckmann, Thomas Popa, M.E. Sapart, Célia Jørgensen, Christian Juncher |
author_sort |
Christiansen, Jesper Riis |
title |
Carbon Emissions From the Edge of the Greenland Ice Sheet Reveal Subglacial Processes of Methane and Carbon Dioxide Turnover |
title_short |
Carbon Emissions From the Edge of the Greenland Ice Sheet Reveal Subglacial Processes of Methane and Carbon Dioxide Turnover |
title_full |
Carbon Emissions From the Edge of the Greenland Ice Sheet Reveal Subglacial Processes of Methane and Carbon Dioxide Turnover |
title_fullStr |
Carbon Emissions From the Edge of the Greenland Ice Sheet Reveal Subglacial Processes of Methane and Carbon Dioxide Turnover |
title_full_unstemmed |
Carbon Emissions From the Edge of the Greenland Ice Sheet Reveal Subglacial Processes of Methane and Carbon Dioxide Turnover |
title_sort |
carbon emissions from the edge of the greenland ice sheet reveal subglacial processes of methane and carbon dioxide turnover |
publishDate |
2021 |
url |
http://hdl.handle.net/2013/ULB-DIPOT:oai:dipot.ulb.ac.be:2013/336749 |
geographic |
Greenland |
geographic_facet |
Greenland |
genre |
Greenland Ice Sheet |
genre_facet |
Greenland Ice Sheet |
op_source |
Journal of Geophysical Research. Biogeosciences, 126 (11 |
op_relation |
uri/info:doi/10.1029/2021JG006308 uri/info:scp/85119837541 http://hdl.handle.net/2013/ULB-DIPOT:oai:dipot.ulb.ac.be:2013/336749 |
_version_ |
1766017970044141568 |