Imprint of intrinsic ocean variability on decadal trends of regional sea level and ocean heat content using synthetic profiles
The global ocean is warming and has absorbed 90% of the Earth Energy Imbalance over 2010–2018 leading to global mean sea level rise. Both ocean heat content (OHC) and sea level trends show large regional deviations from their global means. Both quantities have been estimated from in-situ observation...
| Main Authors: | , , , , , |
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| Format: | Article |
| Language: | English |
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IOP Publishing
2022-01-01
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| Series: | Environmental Research Letters |
| Subjects: | |
| Online Access: | https://doi.org/10.1088/1748-9326/ac5f93 |
| _version_ | 1797747031102455808 |
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| author | William Llovel Nicolas Kolodziejczyk Sally Close Thierry Penduff Jean-Marc Molines Laurent Terray |
| author_facet | William Llovel Nicolas Kolodziejczyk Sally Close Thierry Penduff Jean-Marc Molines Laurent Terray |
| author_sort | William Llovel |
| collection | DOAJ |
| description | The global ocean is warming and has absorbed 90% of the Earth Energy Imbalance over 2010–2018 leading to global mean sea level rise. Both ocean heat content (OHC) and sea level trends show large regional deviations from their global means. Both quantities have been estimated from in-situ observations for years. However, in-situ profile coverage is spatially uneven, leading to uncertainties when assessing both OHC and sea level trends, especially at regional scale. Recently, a new possible driver of regional sea level and OHC trends has been highlighted using eddy-permitting ensemble ocean simulations over multiple decades: non-linear ocean processes produce chaotic fluctuations, which yield random contributions to regional decadal OHC and sea level trends. In-situ measurements capture a combination of the atmospherically-forced response and this intrinsic ocean variability. It is therefore important to understand the imprint of the chaotic ocean variability recorded by the in-situ measurement sampling in order to assess its impact and associated uncertainty on regional budgets. A possible approach to investigate this problem is to use a set of synthetic in-situ -like profiles extracted from an ensemble of forced ocean simulations started from different states and integrated with the same atmospheric forcing. Comparisons between the original ensemble outputs and the remapped, subsampled, in-situ -like profiles elucidate the contribution of chaotic ocean variability to OHC and regional sea level trends. Our results show that intrinsic variability may be large in eddy-active regions in the gridded model outputs, and remains substantial when using the in-situ sampling-based estimates. Using the latter, the same result is also found on large scales, for which atmospheric forcing has been identified as the main driver. Our results suggest accounting for this intrinsic ocean variability when assessing regional OHC and sea level trend budgets on decadal time scales. |
| first_indexed | 2024-03-12T15:45:19Z |
| format | Article |
| id | doaj.art-aa4a3ee282bf4c78a9e2f20efb217abf |
| institution | Directory Open Access Journal |
| issn | 1748-9326 |
| language | English |
| last_indexed | 2024-03-12T15:45:19Z |
| publishDate | 2022-01-01 |
| publisher | IOP Publishing |
| record_format | Article |
| series | Environmental Research Letters |
| spelling | doaj.art-aa4a3ee282bf4c78a9e2f20efb217abf2023-08-09T15:28:08ZengIOP PublishingEnvironmental Research Letters1748-93262022-01-0117404406310.1088/1748-9326/ac5f93Imprint of intrinsic ocean variability on decadal trends of regional sea level and ocean heat content using synthetic profilesWilliam Llovel0https://orcid.org/0000-0002-0798-7595Nicolas Kolodziejczyk1https://orcid.org/0000-0002-0751-1351Sally Close2https://orcid.org/0000-0001-9665-5316Thierry Penduff3https://orcid.org/0000-0002-0407-8564Jean-Marc Molines4https://orcid.org/0000-0003-1665-6816Laurent Terray5https://orcid.org/0000-0001-5512-7074University of Brest/IFREMER/IRD/CNRS, LOPS , Brest, FranceUniversity of Brest/IFREMER/IRD/CNRS, LOPS , Brest, FranceUniversity of Brest/IFREMER/IRD/CNRS, LOPS , Brest, FranceUniversité Grenoble Alpes, CNRS, IRD, Grenoble-INP, IGE , Grenoble, FranceUniversité Grenoble Alpes, CNRS, IRD, Grenoble-INP, IGE , Grenoble, FranceCNRS/CERFACS, CECI , Toulouse, FranceThe global ocean is warming and has absorbed 90% of the Earth Energy Imbalance over 2010–2018 leading to global mean sea level rise. Both ocean heat content (OHC) and sea level trends show large regional deviations from their global means. Both quantities have been estimated from in-situ observations for years. However, in-situ profile coverage is spatially uneven, leading to uncertainties when assessing both OHC and sea level trends, especially at regional scale. Recently, a new possible driver of regional sea level and OHC trends has been highlighted using eddy-permitting ensemble ocean simulations over multiple decades: non-linear ocean processes produce chaotic fluctuations, which yield random contributions to regional decadal OHC and sea level trends. In-situ measurements capture a combination of the atmospherically-forced response and this intrinsic ocean variability. It is therefore important to understand the imprint of the chaotic ocean variability recorded by the in-situ measurement sampling in order to assess its impact and associated uncertainty on regional budgets. A possible approach to investigate this problem is to use a set of synthetic in-situ -like profiles extracted from an ensemble of forced ocean simulations started from different states and integrated with the same atmospheric forcing. Comparisons between the original ensemble outputs and the remapped, subsampled, in-situ -like profiles elucidate the contribution of chaotic ocean variability to OHC and regional sea level trends. Our results show that intrinsic variability may be large in eddy-active regions in the gridded model outputs, and remains substantial when using the in-situ sampling-based estimates. Using the latter, the same result is also found on large scales, for which atmospheric forcing has been identified as the main driver. Our results suggest accounting for this intrinsic ocean variability when assessing regional OHC and sea level trend budgets on decadal time scales.https://doi.org/10.1088/1748-9326/ac5f93ocean heat contentthermosteric sea levelArgo floatlarge ensemble simulationsatmospherically-forced variabilitychaotic intrinsic variability |
| spellingShingle | William Llovel Nicolas Kolodziejczyk Sally Close Thierry Penduff Jean-Marc Molines Laurent Terray Imprint of intrinsic ocean variability on decadal trends of regional sea level and ocean heat content using synthetic profiles Environmental Research Letters ocean heat content thermosteric sea level Argo float large ensemble simulations atmospherically-forced variability chaotic intrinsic variability |
| title | Imprint of intrinsic ocean variability on decadal trends of regional sea level and ocean heat content using synthetic profiles |
| title_full | Imprint of intrinsic ocean variability on decadal trends of regional sea level and ocean heat content using synthetic profiles |
| title_fullStr | Imprint of intrinsic ocean variability on decadal trends of regional sea level and ocean heat content using synthetic profiles |
| title_full_unstemmed | Imprint of intrinsic ocean variability on decadal trends of regional sea level and ocean heat content using synthetic profiles |
| title_short | Imprint of intrinsic ocean variability on decadal trends of regional sea level and ocean heat content using synthetic profiles |
| title_sort | imprint of intrinsic ocean variability on decadal trends of regional sea level and ocean heat content using synthetic profiles |
| topic | ocean heat content thermosteric sea level Argo float large ensemble simulations atmospherically-forced variability chaotic intrinsic variability |
| url | https://doi.org/10.1088/1748-9326/ac5f93 |
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