Central Arctic Ocean surface–atmosphere exchange of CO2 and CH4 constrained by direct measurements
The central Arctic Ocean (CAO) plays an important role in the global carbon cycle, but the current and future exchange of the climate-forcing trace gases methane ( CH 4 ) and carbon dioxide ( CO 2 ) between the CAO and the atmosphere is highly uncertain. In particular, there are very few observation...
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Online Access: | https://doi.org/10.5194/bg-21-671-2024 https://bg.copernicus.org/articles/21/671/2024/ |
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ftcopernicus:oai:publications.copernicus.org:bg111256 2024-09-09T19:23:24+00:00 Central Arctic Ocean surface–atmosphere exchange of CO2 and CH4 constrained by direct measurements Prytherch, John Murto, Sonja Brown, Ian Ulfsbo, Adam Thornton, Brett F. Brüchert, Volker Tjernström, Michael Hermansson, Anna Lunde Nylund, Amanda T. Holthusen, Lina A. 2024-02-02 application/pdf https://doi.org/10.5194/bg-21-671-2024 https://bg.copernicus.org/articles/21/671/2024/ eng eng doi:10.5194/bg-21-671-2024 https://bg.copernicus.org/articles/21/671/2024/ eISSN: 1726-4189 Text 2024 ftcopernicus https://doi.org/10.5194/bg-21-671-2024 2024-08-28T05:24:15Z The central Arctic Ocean (CAO) plays an important role in the global carbon cycle, but the current and future exchange of the climate-forcing trace gases methane ( CH 4 ) and carbon dioxide ( CO 2 ) between the CAO and the atmosphere is highly uncertain. In particular, there are very few observations of near-surface gas concentrations or direct air–sea CO 2 flux estimates and no previously reported direct air–sea CH 4 flux estimates from the CAO. Furthermore, the effect of sea ice on the exchange is not well understood. We present direct measurements of the air–sea flux of CH 4 and CO 2 , as well as air–snow fluxes of CO 2 in the summertime CAO north of 82.5 ∘ N from the Synoptic Arctic Survey (SAS) expedition carried out on the Swedish icebreaker Oden in 2021. Measurements of air–sea CH 4 and CO 2 flux were made using floating chambers deployed in leads accessed from sea ice and from the side of Oden , and air–snow fluxes were determined from chambers deployed on sea ice. Gas transfer velocities determined from fluxes and surface-water-dissolved gas concentrations exhibited a weaker wind speed dependence than existing parameterisations, with a median sea-ice lead gas transfer rate of 2.5 cm h −1 applicable over the observed 10 m wind speed range (1–11 m s −1 ). The average observed air–sea CO 2 flux was − 7.6 mmol m - 2 d - 1 <svg:svg xmlns:svg="http://www.w3.org/2000/svg" width="67pt" height="13pt" class="svg-formula" dspmath="mathimg" md5hash="6add7475d1c0615a24800106f13ac773"><svg:image xmlns:xlink="http://www.w3.org/1999/xlink" xlink:href="bg-21-671-2024-ie00001.svg" width="67pt" height="13pt" src="bg-21-671-2024-ie00001.png"/> </svg:svg> , and the average air–snow CO 2 flux was − 1.1 mmol m - 2 d - 1 <svg:svg xmlns:svg="http://www.w3.org/2000/svg" width="67pt" height="13pt" class="svg-formula" dspmath="mathimg" md5hash="8c4b3213a0a8ab1c445432263e63f72b"><svg:image xmlns:xlink="http://www.w3.org/1999/xlink" xlink:href="bg-21-671-2024-ie00002.svg" width="67pt" height="13pt" ... Text Arctic Arctic Ocean oden Sea ice Copernicus Publications: E-Journals Arctic Arctic Ocean Biogeosciences 21 2 671 688 |
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Open Polar |
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Copernicus Publications: E-Journals |
op_collection_id |
ftcopernicus |
language |
English |
description |
The central Arctic Ocean (CAO) plays an important role in the global carbon cycle, but the current and future exchange of the climate-forcing trace gases methane ( CH 4 ) and carbon dioxide ( CO 2 ) between the CAO and the atmosphere is highly uncertain. In particular, there are very few observations of near-surface gas concentrations or direct air–sea CO 2 flux estimates and no previously reported direct air–sea CH 4 flux estimates from the CAO. Furthermore, the effect of sea ice on the exchange is not well understood. We present direct measurements of the air–sea flux of CH 4 and CO 2 , as well as air–snow fluxes of CO 2 in the summertime CAO north of 82.5 ∘ N from the Synoptic Arctic Survey (SAS) expedition carried out on the Swedish icebreaker Oden in 2021. Measurements of air–sea CH 4 and CO 2 flux were made using floating chambers deployed in leads accessed from sea ice and from the side of Oden , and air–snow fluxes were determined from chambers deployed on sea ice. Gas transfer velocities determined from fluxes and surface-water-dissolved gas concentrations exhibited a weaker wind speed dependence than existing parameterisations, with a median sea-ice lead gas transfer rate of 2.5 cm h −1 applicable over the observed 10 m wind speed range (1–11 m s −1 ). The average observed air–sea CO 2 flux was − 7.6 mmol m - 2 d - 1 <svg:svg xmlns:svg="http://www.w3.org/2000/svg" width="67pt" height="13pt" class="svg-formula" dspmath="mathimg" md5hash="6add7475d1c0615a24800106f13ac773"><svg:image xmlns:xlink="http://www.w3.org/1999/xlink" xlink:href="bg-21-671-2024-ie00001.svg" width="67pt" height="13pt" src="bg-21-671-2024-ie00001.png"/> </svg:svg> , and the average air–snow CO 2 flux was − 1.1 mmol m - 2 d - 1 <svg:svg xmlns:svg="http://www.w3.org/2000/svg" width="67pt" height="13pt" class="svg-formula" dspmath="mathimg" md5hash="8c4b3213a0a8ab1c445432263e63f72b"><svg:image xmlns:xlink="http://www.w3.org/1999/xlink" xlink:href="bg-21-671-2024-ie00002.svg" width="67pt" height="13pt" ... |
format |
Text |
author |
Prytherch, John Murto, Sonja Brown, Ian Ulfsbo, Adam Thornton, Brett F. Brüchert, Volker Tjernström, Michael Hermansson, Anna Lunde Nylund, Amanda T. Holthusen, Lina A. |
spellingShingle |
Prytherch, John Murto, Sonja Brown, Ian Ulfsbo, Adam Thornton, Brett F. Brüchert, Volker Tjernström, Michael Hermansson, Anna Lunde Nylund, Amanda T. Holthusen, Lina A. Central Arctic Ocean surface–atmosphere exchange of CO2 and CH4 constrained by direct measurements |
author_facet |
Prytherch, John Murto, Sonja Brown, Ian Ulfsbo, Adam Thornton, Brett F. Brüchert, Volker Tjernström, Michael Hermansson, Anna Lunde Nylund, Amanda T. Holthusen, Lina A. |
author_sort |
Prytherch, John |
title |
Central Arctic Ocean surface–atmosphere exchange of CO2 and CH4 constrained by direct measurements |
title_short |
Central Arctic Ocean surface–atmosphere exchange of CO2 and CH4 constrained by direct measurements |
title_full |
Central Arctic Ocean surface–atmosphere exchange of CO2 and CH4 constrained by direct measurements |
title_fullStr |
Central Arctic Ocean surface–atmosphere exchange of CO2 and CH4 constrained by direct measurements |
title_full_unstemmed |
Central Arctic Ocean surface–atmosphere exchange of CO2 and CH4 constrained by direct measurements |
title_sort |
central arctic ocean surface–atmosphere exchange of co2 and ch4 constrained by direct measurements |
publishDate |
2024 |
url |
https://doi.org/10.5194/bg-21-671-2024 https://bg.copernicus.org/articles/21/671/2024/ |
geographic |
Arctic Arctic Ocean |
geographic_facet |
Arctic Arctic Ocean |
genre |
Arctic Arctic Ocean oden Sea ice |
genre_facet |
Arctic Arctic Ocean oden Sea ice |
op_source |
eISSN: 1726-4189 |
op_relation |
doi:10.5194/bg-21-671-2024 https://bg.copernicus.org/articles/21/671/2024/ |
op_doi |
https://doi.org/10.5194/bg-21-671-2024 |
container_title |
Biogeosciences |
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21 |
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2 |
container_start_page |
671 |
op_container_end_page |
688 |
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1809763811776790528 |