North Atlantic Subtropical Mode Water properties: Intrinsic and atmospherically-forced interannual variability
This study investigates the contributions of the ocean’s chaotic intrinsic variability (CIV) and atmospherically-forced variability on the interannual fluctuations of the North Atlantic Eighteen Degree Water (EDW) properties. Utilizing a 1/4° regional 50-member ocean/sea-ice ensemb...
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ftcopernicus:oai:publications.copernicus.org:egusphere119471 2024-06-23T07:55:00+00:00 North Atlantic Subtropical Mode Water properties: Intrinsic and atmospherically-forced interannual variability Narinc, Olivier Penduff, Thierry Maze, Guillaume Leroux, Stéphanie Molines, Jean-Marc 2024-04-25 application/pdf https://doi.org/10.5194/egusphere-2024-1146 https://egusphere.copernicus.org/preprints/2024/egusphere-2024-1146/ eng eng doi:10.5194/egusphere-2024-1146 https://egusphere.copernicus.org/preprints/2024/egusphere-2024-1146/ eISSN: Text 2024 ftcopernicus https://doi.org/10.5194/egusphere-2024-1146 2024-06-13T01:24:45Z This study investigates the contributions of the ocean’s chaotic intrinsic variability (CIV) and atmospherically-forced variability on the interannual fluctuations of the North Atlantic Eighteen Degree Water (EDW) properties. Utilizing a 1/4° regional 50-member ocean/sea-ice ensemble simulation driven by an original surface forcing method and perturbed initially, the forced variability of EDW properties is estimated from ensemble mean fluctuations, while CIV is determined from deviations around the ensemble mean within each member. The model successfully captures the main features of EDW, showing good agreement with observation-based ARMOR3D data in terms of location, seasonality, mean temperature and volume, and interannual variance of its main properties. CIV significantly impacts EDW, explaining 10–13 and 28–44 % of the interannual variance of its geometric and thermohaline mean properties, respectively, with a maximum imprint on EDW temperature. Observed and simulated intrinsic-to-total variance ratios are mostly consistent, dispelling concerns about a signal-to-noise paradox. This study also illustrates the advantages of ensemble simulations over single simulations in understanding oceanic fluctuations and attributing them to external drivers, while also cautioning against overreliance on individual simulations assessments. Text North Atlantic Sea ice Copernicus Publications: E-Journals |
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Copernicus Publications: E-Journals |
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English |
description |
This study investigates the contributions of the ocean’s chaotic intrinsic variability (CIV) and atmospherically-forced variability on the interannual fluctuations of the North Atlantic Eighteen Degree Water (EDW) properties. Utilizing a 1/4° regional 50-member ocean/sea-ice ensemble simulation driven by an original surface forcing method and perturbed initially, the forced variability of EDW properties is estimated from ensemble mean fluctuations, while CIV is determined from deviations around the ensemble mean within each member. The model successfully captures the main features of EDW, showing good agreement with observation-based ARMOR3D data in terms of location, seasonality, mean temperature and volume, and interannual variance of its main properties. CIV significantly impacts EDW, explaining 10–13 and 28–44 % of the interannual variance of its geometric and thermohaline mean properties, respectively, with a maximum imprint on EDW temperature. Observed and simulated intrinsic-to-total variance ratios are mostly consistent, dispelling concerns about a signal-to-noise paradox. This study also illustrates the advantages of ensemble simulations over single simulations in understanding oceanic fluctuations and attributing them to external drivers, while also cautioning against overreliance on individual simulations assessments. |
format |
Text |
author |
Narinc, Olivier Penduff, Thierry Maze, Guillaume Leroux, Stéphanie Molines, Jean-Marc |
spellingShingle |
Narinc, Olivier Penduff, Thierry Maze, Guillaume Leroux, Stéphanie Molines, Jean-Marc North Atlantic Subtropical Mode Water properties: Intrinsic and atmospherically-forced interannual variability |
author_facet |
Narinc, Olivier Penduff, Thierry Maze, Guillaume Leroux, Stéphanie Molines, Jean-Marc |
author_sort |
Narinc, Olivier |
title |
North Atlantic Subtropical Mode Water properties: Intrinsic and atmospherically-forced interannual variability |
title_short |
North Atlantic Subtropical Mode Water properties: Intrinsic and atmospherically-forced interannual variability |
title_full |
North Atlantic Subtropical Mode Water properties: Intrinsic and atmospherically-forced interannual variability |
title_fullStr |
North Atlantic Subtropical Mode Water properties: Intrinsic and atmospherically-forced interannual variability |
title_full_unstemmed |
North Atlantic Subtropical Mode Water properties: Intrinsic and atmospherically-forced interannual variability |
title_sort |
north atlantic subtropical mode water properties: intrinsic and atmospherically-forced interannual variability |
publishDate |
2024 |
url |
https://doi.org/10.5194/egusphere-2024-1146 https://egusphere.copernicus.org/preprints/2024/egusphere-2024-1146/ |
genre |
North Atlantic Sea ice |
genre_facet |
North Atlantic Sea ice |
op_source |
eISSN: |
op_relation |
doi:10.5194/egusphere-2024-1146 https://egusphere.copernicus.org/preprints/2024/egusphere-2024-1146/ |
op_doi |
https://doi.org/10.5194/egusphere-2024-1146 |
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1802647385882492928 |