Regional versus remote atmosphere‐ocean drivers of the rapid projected intensification of the East Australian Current
Like many western boundary currents, the East Australian Current extension is projected to get stronger and warmer in the future. The CMIP5 multi‐model mean (MMM) projection suggests up to 5°C of warming under an RCP85 scenario by 2100. Previous studies employed Sverdrup balance to associate a trend...
Published in: | Journal of Geophysical Research: Oceans |
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American Geophysical Union
2020
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Online Access: | https://nrl.northumbria.ac.uk/id/eprint/43570/ https://doi.org/10.1029/2019jc015889 https://nrl.northumbria.ac.uk/id/eprint/43570/7/2019JC015889.pdf https://nrl.northumbria.ac.uk/id/eprint/43570/1/2019JC015889.pdf |
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ftunivnorthumb:oai:nrl.northumbria.ac.uk:43570 2023-05-15T18:25:46+02:00 Regional versus remote atmosphere‐ocean drivers of the rapid projected intensification of the East Australian Current Bull, Christopher Kiss, Andrew E. Sen Gupta, Alex Jourdain, Nicolas C. Argüeso, Daniel Di Luca, Alejandro Sérazin, Guillaume 2020-07 text https://nrl.northumbria.ac.uk/id/eprint/43570/ https://doi.org/10.1029/2019jc015889 https://nrl.northumbria.ac.uk/id/eprint/43570/7/2019JC015889.pdf https://nrl.northumbria.ac.uk/id/eprint/43570/1/2019JC015889.pdf en eng American Geophysical Union https://nrl.northumbria.ac.uk/id/eprint/43570/7/2019JC015889.pdf https://nrl.northumbria.ac.uk/id/eprint/43570/1/2019JC015889.pdf Bull, Christopher, Kiss, Andrew E., Sen Gupta, Alex, Jourdain, Nicolas C., Argüeso, Daniel, Di Luca, Alejandro and Sérazin, Guillaume (2020) Regional versus remote atmosphere‐ocean drivers of the rapid projected intensification of the East Australian Current. Journal of Geophysical Research: Oceans, 125 (7). e2019JC015889. ISSN 2169-9275 cc_by_4_0 CC-BY F700 Ocean Sciences F800 Physical and Terrestrial Geographical and Environmental Sciences Article PeerReviewed 2020 ftunivnorthumb https://doi.org/10.1029/2019jc015889 2022-09-25T06:12:17Z Like many western boundary currents, the East Australian Current extension is projected to get stronger and warmer in the future. The CMIP5 multi‐model mean (MMM) projection suggests up to 5°C of warming under an RCP85 scenario by 2100. Previous studies employed Sverdrup balance to associate a trend in basin wide zonally integrated wind stress curl (resulting from the multi‐decadal poleward intensification in the westerly winds over the Southern Ocean) with enhanced transport in the EAC extension. Possible regional drivers are yet to be considered. Here, we introduce the NEMO‐OASIS‐WRF coupled regional climate model as a framework to improve our understanding of CMIP5 projections. We analyse a hierarchy of simulations in which the regional atmosphere and ocean circulations are allowed to freely evolve subject to boundary conditions that represent present day and CMIP5 RCP8.5 climate change anomalies. Evaluation of the historical simulation shows an EAC extension that is stronger than similar ocean‐only models and observations. This bias is not explained by a linear response to differences in wind stress. The climate change simulations show that regional atmospheric CMIP5 MMM anomalies drive 73% of the projected 12 Sv increase in EAC extension transport whereas the remote ocean boundary conditions and regional radiative forcing (greenhouse gases within the domain) play a smaller role. The importance of regional changes in wind stress curl in driving the enhanced EAC extension is consistent with linear theory where the NEMO‐OASIS‐WRF response is closer to linear transport estimates compared to the CMIP5 MMM. Article in Journal/Newspaper Southern Ocean Northumbria University, Newcastle: Northumbria Research Link (NRL) Curl ENVELOPE(-63.071,-63.071,-70.797,-70.797) Southern Ocean Journal of Geophysical Research: Oceans 125 7 |
institution |
Open Polar |
collection |
Northumbria University, Newcastle: Northumbria Research Link (NRL) |
op_collection_id |
ftunivnorthumb |
language |
English |
topic |
F700 Ocean Sciences F800 Physical and Terrestrial Geographical and Environmental Sciences |
spellingShingle |
F700 Ocean Sciences F800 Physical and Terrestrial Geographical and Environmental Sciences Bull, Christopher Kiss, Andrew E. Sen Gupta, Alex Jourdain, Nicolas C. Argüeso, Daniel Di Luca, Alejandro Sérazin, Guillaume Regional versus remote atmosphere‐ocean drivers of the rapid projected intensification of the East Australian Current |
topic_facet |
F700 Ocean Sciences F800 Physical and Terrestrial Geographical and Environmental Sciences |
description |
Like many western boundary currents, the East Australian Current extension is projected to get stronger and warmer in the future. The CMIP5 multi‐model mean (MMM) projection suggests up to 5°C of warming under an RCP85 scenario by 2100. Previous studies employed Sverdrup balance to associate a trend in basin wide zonally integrated wind stress curl (resulting from the multi‐decadal poleward intensification in the westerly winds over the Southern Ocean) with enhanced transport in the EAC extension. Possible regional drivers are yet to be considered. Here, we introduce the NEMO‐OASIS‐WRF coupled regional climate model as a framework to improve our understanding of CMIP5 projections. We analyse a hierarchy of simulations in which the regional atmosphere and ocean circulations are allowed to freely evolve subject to boundary conditions that represent present day and CMIP5 RCP8.5 climate change anomalies. Evaluation of the historical simulation shows an EAC extension that is stronger than similar ocean‐only models and observations. This bias is not explained by a linear response to differences in wind stress. The climate change simulations show that regional atmospheric CMIP5 MMM anomalies drive 73% of the projected 12 Sv increase in EAC extension transport whereas the remote ocean boundary conditions and regional radiative forcing (greenhouse gases within the domain) play a smaller role. The importance of regional changes in wind stress curl in driving the enhanced EAC extension is consistent with linear theory where the NEMO‐OASIS‐WRF response is closer to linear transport estimates compared to the CMIP5 MMM. |
format |
Article in Journal/Newspaper |
author |
Bull, Christopher Kiss, Andrew E. Sen Gupta, Alex Jourdain, Nicolas C. Argüeso, Daniel Di Luca, Alejandro Sérazin, Guillaume |
author_facet |
Bull, Christopher Kiss, Andrew E. Sen Gupta, Alex Jourdain, Nicolas C. Argüeso, Daniel Di Luca, Alejandro Sérazin, Guillaume |
author_sort |
Bull, Christopher |
title |
Regional versus remote atmosphere‐ocean drivers of the rapid projected intensification of the East Australian Current |
title_short |
Regional versus remote atmosphere‐ocean drivers of the rapid projected intensification of the East Australian Current |
title_full |
Regional versus remote atmosphere‐ocean drivers of the rapid projected intensification of the East Australian Current |
title_fullStr |
Regional versus remote atmosphere‐ocean drivers of the rapid projected intensification of the East Australian Current |
title_full_unstemmed |
Regional versus remote atmosphere‐ocean drivers of the rapid projected intensification of the East Australian Current |
title_sort |
regional versus remote atmosphere‐ocean drivers of the rapid projected intensification of the east australian current |
publisher |
American Geophysical Union |
publishDate |
2020 |
url |
https://nrl.northumbria.ac.uk/id/eprint/43570/ https://doi.org/10.1029/2019jc015889 https://nrl.northumbria.ac.uk/id/eprint/43570/7/2019JC015889.pdf https://nrl.northumbria.ac.uk/id/eprint/43570/1/2019JC015889.pdf |
long_lat |
ENVELOPE(-63.071,-63.071,-70.797,-70.797) |
geographic |
Curl Southern Ocean |
geographic_facet |
Curl Southern Ocean |
genre |
Southern Ocean |
genre_facet |
Southern Ocean |
op_relation |
https://nrl.northumbria.ac.uk/id/eprint/43570/7/2019JC015889.pdf https://nrl.northumbria.ac.uk/id/eprint/43570/1/2019JC015889.pdf Bull, Christopher, Kiss, Andrew E., Sen Gupta, Alex, Jourdain, Nicolas C., Argüeso, Daniel, Di Luca, Alejandro and Sérazin, Guillaume (2020) Regional versus remote atmosphere‐ocean drivers of the rapid projected intensification of the East Australian Current. Journal of Geophysical Research: Oceans, 125 (7). e2019JC015889. ISSN 2169-9275 |
op_rights |
cc_by_4_0 |
op_rightsnorm |
CC-BY |
op_doi |
https://doi.org/10.1029/2019jc015889 |
container_title |
Journal of Geophysical Research: Oceans |
container_volume |
125 |
container_issue |
7 |
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1766207404430589952 |