Ocean (De)oxygenation Across the Last Deglaciation: Insights for the Future
Anthropogenic warming is expected to drive oxygen out of the ocean as the water temperature rises and the rate of exchange between subsurface waters and the atmosphere slows due to enhanced upper ocean density stratification. Observations from recent decades are tantalizingly consistent with this pr...
| Main Authors: | , , , |
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| Format: | Article |
| Language: | English |
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The Oceanography Society
2014-03-01
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| Series: | Oceanography |
| Subjects: | |
| Online Access: | http://tos.org/oceanography/archive/27-1_jaccard.pdf |
| _version_ | 1819032137225994240 |
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| author | Samuel L. Jaccard Eric D. Galbraith Thomas L. Frolicher Nicolas Gruber |
| author_facet | Samuel L. Jaccard Eric D. Galbraith Thomas L. Frolicher Nicolas Gruber |
| author_sort | Samuel L. Jaccard |
| collection | DOAJ |
| description | Anthropogenic warming is expected to drive oxygen out of the ocean as the water temperature rises and the rate of exchange between subsurface waters and the atmosphere slows due to enhanced upper ocean density stratification. Observations from recent decades are tantalizingly consistent with this prediction, though these changes remain subtle in the face of natural variability. Earth system model projections unanimously predict a long-term decrease in the global ocean oxygen inventory, but show regional discrepancies, particularly in the most oxygen-depleted waters, owing to the complex interplay between oxygen supply pathways and oxygen consumption. The geological record provides an orthogonal perspective, showing how the oceanic oxygen content varied in response to prior episodes of climate change. These past changes were much slower than the current, anthropogenic change, but can help to appraise sensitivities, and point toward potentially dominant mechanisms of change. Consistent with the model projections, marine sediments recorded an overall expansion of low-oxygen waters in the upper ocean as it warmed at the end of the last ice age. This expansion was not linearly related with temperature, though, but reached a deoxygenation extreme midway through the warming. Meanwhile, the deep ocean became better oxygenated, opposite the general expectation. These observations require that significant changes in apparent oxygen utilization occurred, suggesting that they will also be important in the future. |
| first_indexed | 2024-12-21T06:57:09Z |
| format | Article |
| id | doaj.art-91cfcbe36cda4e66922218b7a78b9ce9 |
| institution | Directory Open Access Journal |
| issn | 1042-8275 |
| language | English |
| last_indexed | 2024-12-21T06:57:09Z |
| publishDate | 2014-03-01 |
| publisher | The Oceanography Society |
| record_format | Article |
| series | Oceanography |
| spelling | doaj.art-91cfcbe36cda4e66922218b7a78b9ce92022-12-21T19:12:18ZengThe Oceanography SocietyOceanography1042-82752014-03-01271263510.5670/oceanog.2014.05Ocean (De)oxygenation Across the Last Deglaciation: Insights for the FutureSamuel L. Jaccard0Eric D. Galbraith1Thomas L. Frolicher2Nicolas Gruber3University of BernMcGill UniversityETH ZurichETH ZurichAnthropogenic warming is expected to drive oxygen out of the ocean as the water temperature rises and the rate of exchange between subsurface waters and the atmosphere slows due to enhanced upper ocean density stratification. Observations from recent decades are tantalizingly consistent with this prediction, though these changes remain subtle in the face of natural variability. Earth system model projections unanimously predict a long-term decrease in the global ocean oxygen inventory, but show regional discrepancies, particularly in the most oxygen-depleted waters, owing to the complex interplay between oxygen supply pathways and oxygen consumption. The geological record provides an orthogonal perspective, showing how the oceanic oxygen content varied in response to prior episodes of climate change. These past changes were much slower than the current, anthropogenic change, but can help to appraise sensitivities, and point toward potentially dominant mechanisms of change. Consistent with the model projections, marine sediments recorded an overall expansion of low-oxygen waters in the upper ocean as it warmed at the end of the last ice age. This expansion was not linearly related with temperature, though, but reached a deoxygenation extreme midway through the warming. Meanwhile, the deep ocean became better oxygenated, opposite the general expectation. These observations require that significant changes in apparent oxygen utilization occurred, suggesting that they will also be important in the future.http://tos.org/oceanography/archive/27-1_jaccard.pdfocean oxygenocean warmingdeglaciation |
| spellingShingle | Samuel L. Jaccard Eric D. Galbraith Thomas L. Frolicher Nicolas Gruber Ocean (De)oxygenation Across the Last Deglaciation: Insights for the Future Oceanography ocean oxygen ocean warming deglaciation |
| title | Ocean (De)oxygenation Across the Last Deglaciation: Insights for the Future |
| title_full | Ocean (De)oxygenation Across the Last Deglaciation: Insights for the Future |
| title_fullStr | Ocean (De)oxygenation Across the Last Deglaciation: Insights for the Future |
| title_full_unstemmed | Ocean (De)oxygenation Across the Last Deglaciation: Insights for the Future |
| title_short | Ocean (De)oxygenation Across the Last Deglaciation: Insights for the Future |
| title_sort | ocean de oxygenation across the last deglaciation insights for the future |
| topic | ocean oxygen ocean warming deglaciation |
| url | http://tos.org/oceanography/archive/27-1_jaccard.pdf |
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