The Effect of Antarctic Sea Ice on Southern Ocean Carbon Outgassing: Capping Versus Light Attenuation
We examine the role of sea ice in controlling air-sea carbon fluxes around Antarctica using numerical simulations and idealized theory. Upwelling of carbon and nutrient-rich deep waters in the Southern Ocean promotes outgassing of CO₂ and fuels the biological flux of sinking organic particles. Sea i...
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American Geophysical Union (AGU)
2021
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ftmit:oai:dspace.mit.edu:1721.1/133137 2023-06-11T04:06:45+02:00 The Effect of Antarctic Sea Ice on Southern Ocean Carbon Outgassing: Capping Versus Light Attenuation Gupta, Mukund Follows, Michael J Lauderdale, Jonathan Massachusetts Institute of Technology. Department of Earth, Atmospheric, and Planetary Sciences 2021-10-26T17:03:23Z application/pdf https://hdl.handle.net/1721.1/133137 en eng American Geophysical Union (AGU) http://dx.doi.org/10.1029/2019gb006489 Global Biogeochemical Cycles 0886-6236 1944-9224 https://hdl.handle.net/1721.1/133137 Gupta, Mukund et al. "The effect of Antarctic sea ice on Southern Ocean carbon outgassing: Capping versus light attenuation." Global Biogeochemical Cycles 34 (August 2020): e2019GB006489. © 2020 American Geophysical Union Article is made available in accordance with the publisher's policy and may be subject to US copyright law. Please refer to the publisher's site for terms of use. Prof. Follows Article http://purl.org/eprint/type/JournalArticle 2021 ftmit https://doi.org/10.1029/2019gb006489 2023-05-29T08:23:53Z We examine the role of sea ice in controlling air-sea carbon fluxes around Antarctica using numerical simulations and idealized theory. Upwelling of carbon and nutrient-rich deep waters in the Southern Ocean promotes outgassing of CO₂ and fuels the biological flux of sinking organic particles. Sea ice inhibits outgassing, by presenting a physical barrier to air-sea exchange (capping), and decreases biological uptake by reducing the flux of photons to the ocean surface (light attenuation). These two compensating effects suggest that changes in sea ice may have a modest impact on the air-sea flux of CO₂ in the region. Numerical simulations support this inference, showing that the net integrated flux remains nearly constant for a large range of sea ice fractions when the ice cover is uniform and time-invariant. Consequently, the outgassing flux is only significantly capped when the ice cover is nearly complete. A simple analytical model shows that the compensation strength can be uniquely characterized by a single parameter that depends on the flow residence time scale under ice, relative to the air-sea equilibration and biological time scales. When the ice is seasonal, compensation between capping and light attenuation is weakened, but still significant. The spring months are particularly important due to the co-occurrence of an extended sea ice cover and the presence of sunlight. NSF (Project 1545859) Article in Journal/Newspaper Antarc* Antarctic Antarctica Sea ice Southern Ocean DSpace@MIT (Massachusetts Institute of Technology) Antarctic Southern Ocean Global Biogeochemical Cycles 34 8 |
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DSpace@MIT (Massachusetts Institute of Technology) |
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ftmit |
language |
English |
description |
We examine the role of sea ice in controlling air-sea carbon fluxes around Antarctica using numerical simulations and idealized theory. Upwelling of carbon and nutrient-rich deep waters in the Southern Ocean promotes outgassing of CO₂ and fuels the biological flux of sinking organic particles. Sea ice inhibits outgassing, by presenting a physical barrier to air-sea exchange (capping), and decreases biological uptake by reducing the flux of photons to the ocean surface (light attenuation). These two compensating effects suggest that changes in sea ice may have a modest impact on the air-sea flux of CO₂ in the region. Numerical simulations support this inference, showing that the net integrated flux remains nearly constant for a large range of sea ice fractions when the ice cover is uniform and time-invariant. Consequently, the outgassing flux is only significantly capped when the ice cover is nearly complete. A simple analytical model shows that the compensation strength can be uniquely characterized by a single parameter that depends on the flow residence time scale under ice, relative to the air-sea equilibration and biological time scales. When the ice is seasonal, compensation between capping and light attenuation is weakened, but still significant. The spring months are particularly important due to the co-occurrence of an extended sea ice cover and the presence of sunlight. NSF (Project 1545859) |
author2 |
Massachusetts Institute of Technology. Department of Earth, Atmospheric, and Planetary Sciences |
format |
Article in Journal/Newspaper |
author |
Gupta, Mukund Follows, Michael J Lauderdale, Jonathan |
spellingShingle |
Gupta, Mukund Follows, Michael J Lauderdale, Jonathan The Effect of Antarctic Sea Ice on Southern Ocean Carbon Outgassing: Capping Versus Light Attenuation |
author_facet |
Gupta, Mukund Follows, Michael J Lauderdale, Jonathan |
author_sort |
Gupta, Mukund |
title |
The Effect of Antarctic Sea Ice on Southern Ocean Carbon Outgassing: Capping Versus Light Attenuation |
title_short |
The Effect of Antarctic Sea Ice on Southern Ocean Carbon Outgassing: Capping Versus Light Attenuation |
title_full |
The Effect of Antarctic Sea Ice on Southern Ocean Carbon Outgassing: Capping Versus Light Attenuation |
title_fullStr |
The Effect of Antarctic Sea Ice on Southern Ocean Carbon Outgassing: Capping Versus Light Attenuation |
title_full_unstemmed |
The Effect of Antarctic Sea Ice on Southern Ocean Carbon Outgassing: Capping Versus Light Attenuation |
title_sort |
effect of antarctic sea ice on southern ocean carbon outgassing: capping versus light attenuation |
publisher |
American Geophysical Union (AGU) |
publishDate |
2021 |
url |
https://hdl.handle.net/1721.1/133137 |
geographic |
Antarctic Southern Ocean |
geographic_facet |
Antarctic Southern Ocean |
genre |
Antarc* Antarctic Antarctica Sea ice Southern Ocean |
genre_facet |
Antarc* Antarctic Antarctica Sea ice Southern Ocean |
op_source |
Prof. Follows |
op_relation |
http://dx.doi.org/10.1029/2019gb006489 Global Biogeochemical Cycles 0886-6236 1944-9224 https://hdl.handle.net/1721.1/133137 Gupta, Mukund et al. "The effect of Antarctic sea ice on Southern Ocean carbon outgassing: Capping versus light attenuation." Global Biogeochemical Cycles 34 (August 2020): e2019GB006489. © 2020 American Geophysical Union |
op_rights |
Article is made available in accordance with the publisher's policy and may be subject to US copyright law. Please refer to the publisher's site for terms of use. |
op_doi |
https://doi.org/10.1029/2019gb006489 |
container_title |
Global Biogeochemical Cycles |
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34 |
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8 |
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1768378865872273408 |