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 (EAC) extension is projected to get stronger and warmer in the future. The CMIP5 multimodel mean (MMM) projection suggests up to 5°C of warming under an RCP85 scenario by 2100. Previous studies employed Sverdrup balance to associate a...
Published in: | Journal of Geophysical Research: Oceans |
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American Geophysical Union (AGU)
2020
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Online Access: | http://hdl.handle.net/1959.4/unsworks_73142 https://unsworks.unsw.edu.au/bitstreams/ffc31ae2-92b4-4817-bcde-7073d903ab57/download https://doi.org/10.1029/2019JC015889 |
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ftunswworks:oai:unsworks.library.unsw.edu.au:1959.4/unsworks_73142 2024-06-02T08:14:49+00:00 Regional Versus Remote Atmosphere-Ocean Drivers of the Rapid Projected Intensification of the East Australian Current Bull, CYS Kiss, AE Gupta, AS Jourdain, NC Argüeso, D Di Luca, A Sérazin, G Serazin, Guillaume 2020-07-01 application/pdf http://hdl.handle.net/1959.4/unsworks_73142 https://unsworks.unsw.edu.au/bitstreams/ffc31ae2-92b4-4817-bcde-7073d903ab57/download https://doi.org/10.1029/2019JC015889 unknown American Geophysical Union (AGU) http://hdl.handle.net/1959.4/unsworks_73142 https://unsworks.unsw.edu.au/bitstreams/ffc31ae2-92b4-4817-bcde-7073d903ab57/download https://doi.org/10.1029/2019JC015889 open access https://purl.org/coar/access_right/c_abf2 CC-BY-NC-ND https://creativecommons.org/licenses/by-nc-nd/4.0/ free_to_read urn:ISSN:2169-9275 urn:ISSN:2169-9291 Journal of Geophysical Research: Oceans, 125, 7 13 Climate Action 14 Life Below Water anzsrc-for: 0404 Geophysics anzsrc-for: 0405 Oceanography anzsrc-for: 0406 Physical Geography and Environmental Geoscience journal article http://purl.org/coar/resource_type/c_6501 2020 ftunswworks https://doi.org/10.1029/2019JC015889 2024-05-07T23:55:04Z Like many western boundary currents, the East Australian Current (EAC) extension is projected to get stronger and warmer in the future. The CMIP5 multimodel 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 multidecadal 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 analyze 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 UNSW Sydney (The University of New South Wales): UNSWorks Curl ENVELOPE(-63.071,-63.071,-70.797,-70.797) Southern Ocean Journal of Geophysical Research: Oceans 125 7 |
institution |
Open Polar |
collection |
UNSW Sydney (The University of New South Wales): UNSWorks |
op_collection_id |
ftunswworks |
language |
unknown |
topic |
13 Climate Action 14 Life Below Water anzsrc-for: 0404 Geophysics anzsrc-for: 0405 Oceanography anzsrc-for: 0406 Physical Geography and Environmental Geoscience |
spellingShingle |
13 Climate Action 14 Life Below Water anzsrc-for: 0404 Geophysics anzsrc-for: 0405 Oceanography anzsrc-for: 0406 Physical Geography and Environmental Geoscience Bull, CYS Kiss, AE Gupta, AS Jourdain, NC Argüeso, D Di Luca, A Sérazin, G Serazin, Guillaume Regional Versus Remote Atmosphere-Ocean Drivers of the Rapid Projected Intensification of the East Australian Current |
topic_facet |
13 Climate Action 14 Life Below Water anzsrc-for: 0404 Geophysics anzsrc-for: 0405 Oceanography anzsrc-for: 0406 Physical Geography and Environmental Geoscience |
description |
Like many western boundary currents, the East Australian Current (EAC) extension is projected to get stronger and warmer in the future. The CMIP5 multimodel 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 multidecadal 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 analyze 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, CYS Kiss, AE Gupta, AS Jourdain, NC Argüeso, D Di Luca, A Sérazin, G Serazin, Guillaume |
author_facet |
Bull, CYS Kiss, AE Gupta, AS Jourdain, NC Argüeso, D Di Luca, A Sérazin, G Serazin, Guillaume |
author_sort |
Bull, CYS |
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 (AGU) |
publishDate |
2020 |
url |
http://hdl.handle.net/1959.4/unsworks_73142 https://unsworks.unsw.edu.au/bitstreams/ffc31ae2-92b4-4817-bcde-7073d903ab57/download https://doi.org/10.1029/2019JC015889 |
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_source |
urn:ISSN:2169-9275 urn:ISSN:2169-9291 Journal of Geophysical Research: Oceans, 125, 7 |
op_relation |
http://hdl.handle.net/1959.4/unsworks_73142 https://unsworks.unsw.edu.au/bitstreams/ffc31ae2-92b4-4817-bcde-7073d903ab57/download https://doi.org/10.1029/2019JC015889 |
op_rights |
open access https://purl.org/coar/access_right/c_abf2 CC-BY-NC-ND https://creativecommons.org/licenses/by-nc-nd/4.0/ free_to_read |
op_doi |
https://doi.org/10.1029/2019JC015889 |
container_title |
Journal of Geophysical Research: Oceans |
container_volume |
125 |
container_issue |
7 |
_version_ |
1800738801696374784 |