Mitigating climate biases in the midlatitude North Atlantic by increasing model resolution: SST gradients and their relation to blocking and the jet
Starting to resolve the oceanic mesoscale in climate models is a step change in model fidelity. This study examines how certain obstinate biases in the midlatitude North Atlantic respond to increasing resolution (from 1° to 0.25° in the ocean) and how such biases in sea surface temperature (SST) aff...
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ftcaltechauth:oai:authors.library.caltech.edu:117956 2023-05-15T17:28:35+02:00 Mitigating climate biases in the midlatitude North Atlantic by increasing model resolution: SST gradients and their relation to blocking and the jet Athanasiadis, Panos J. Ogawa, Fumiaki Omrani, Nour-Eddine Keenlyside, Noel Schiemann, Reinhard Baker, Alexander J. Vidale, Pier Luigi Bellucci, Alessio Ruggieri, Paolo Haarsma, Rein Roberts, Malcolm Roberts, Chris Novak, Lenka Gualdi, Silvio 2022-11 https://authors.library.caltech.edu/117956/ https://resolver.caltech.edu/CaltechAUTHORS:20221121-712406200.21 unknown American Meteorological Society Athanasiadis, Panos J. and Ogawa, Fumiaki and Omrani, Nour-Eddine and Keenlyside, Noel and Schiemann, Reinhard and Baker, Alexander J. and Vidale, Pier Luigi and Bellucci, Alessio and Ruggieri, Paolo and Haarsma, Rein and Roberts, Malcolm and Roberts, Chris and Novak, Lenka and Gualdi, Silvio (2022) Mitigating climate biases in the midlatitude North Atlantic by increasing model resolution: SST gradients and their relation to blocking and the jet. Journal of Climate, 35 (21). pp. 3385-3406. ISSN 0894-8755. doi:10.1175/jcli-d-21-0515.1. https://resolver.caltech.edu/CaltechAUTHORS:20221121-712406200.21 <https://resolver.caltech.edu/CaltechAUTHORS:20221121-712406200.21> Article PeerReviewed 2022 ftcaltechauth https://doi.org/10.1175/jcli-d-21-0515.1 2022-12-08T18:58:02Z Starting to resolve the oceanic mesoscale in climate models is a step change in model fidelity. This study examines how certain obstinate biases in the midlatitude North Atlantic respond to increasing resolution (from 1° to 0.25° in the ocean) and how such biases in sea surface temperature (SST) affect the atmosphere. Using a multi-model ensemble of historical climate simulations run at different horizontal resolutions, it is shown that a severe cold SST bias in the central North Atlantic, common to many ocean models, is significantly reduced with increasing resolution. The associated bias in the time-mean meridional SST gradient is shown to relate to a positive bias in low-level baroclinicity, while the cold SST bias causes biases also in static stability and diabatic heating in the interior of the atmosphere. The changes in baroclinicity and diabatic heating brought by increasing resolution lead to improvements in European blocking and eddy-driven jet variability. Across the multi-model ensemble a clear relationship is found between the climatological meridional SST gradients in the broader Gulf Stream Extension area and two aspects of the atmospheric circulation: the frequency of high-latitude blocking and the southern-jet regime. This relationship is thought to reflect the two-way interaction (with a positive feedback) between the respective oceanic and atmospheric anomalies. These North Atlantic SST anomalies are shown to be important in forcing significant responses in the midlatitude atmospheric circulation, including jet variability and the stormtrack. Further increases in oceanic and atmospheric resolution are expected to lead to additional improvements in the representation of Euro-Atlantic climate. Article in Journal/Newspaper North Atlantic Caltech Authors (California Institute of Technology) Journal of Climate 35 21 6985 7006 |
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Caltech Authors (California Institute of Technology) |
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description |
Starting to resolve the oceanic mesoscale in climate models is a step change in model fidelity. This study examines how certain obstinate biases in the midlatitude North Atlantic respond to increasing resolution (from 1° to 0.25° in the ocean) and how such biases in sea surface temperature (SST) affect the atmosphere. Using a multi-model ensemble of historical climate simulations run at different horizontal resolutions, it is shown that a severe cold SST bias in the central North Atlantic, common to many ocean models, is significantly reduced with increasing resolution. The associated bias in the time-mean meridional SST gradient is shown to relate to a positive bias in low-level baroclinicity, while the cold SST bias causes biases also in static stability and diabatic heating in the interior of the atmosphere. The changes in baroclinicity and diabatic heating brought by increasing resolution lead to improvements in European blocking and eddy-driven jet variability. Across the multi-model ensemble a clear relationship is found between the climatological meridional SST gradients in the broader Gulf Stream Extension area and two aspects of the atmospheric circulation: the frequency of high-latitude blocking and the southern-jet regime. This relationship is thought to reflect the two-way interaction (with a positive feedback) between the respective oceanic and atmospheric anomalies. These North Atlantic SST anomalies are shown to be important in forcing significant responses in the midlatitude atmospheric circulation, including jet variability and the stormtrack. Further increases in oceanic and atmospheric resolution are expected to lead to additional improvements in the representation of Euro-Atlantic climate. |
format |
Article in Journal/Newspaper |
author |
Athanasiadis, Panos J. Ogawa, Fumiaki Omrani, Nour-Eddine Keenlyside, Noel Schiemann, Reinhard Baker, Alexander J. Vidale, Pier Luigi Bellucci, Alessio Ruggieri, Paolo Haarsma, Rein Roberts, Malcolm Roberts, Chris Novak, Lenka Gualdi, Silvio |
spellingShingle |
Athanasiadis, Panos J. Ogawa, Fumiaki Omrani, Nour-Eddine Keenlyside, Noel Schiemann, Reinhard Baker, Alexander J. Vidale, Pier Luigi Bellucci, Alessio Ruggieri, Paolo Haarsma, Rein Roberts, Malcolm Roberts, Chris Novak, Lenka Gualdi, Silvio Mitigating climate biases in the midlatitude North Atlantic by increasing model resolution: SST gradients and their relation to blocking and the jet |
author_facet |
Athanasiadis, Panos J. Ogawa, Fumiaki Omrani, Nour-Eddine Keenlyside, Noel Schiemann, Reinhard Baker, Alexander J. Vidale, Pier Luigi Bellucci, Alessio Ruggieri, Paolo Haarsma, Rein Roberts, Malcolm Roberts, Chris Novak, Lenka Gualdi, Silvio |
author_sort |
Athanasiadis, Panos J. |
title |
Mitigating climate biases in the midlatitude North Atlantic by increasing model resolution: SST gradients and their relation to blocking and the jet |
title_short |
Mitigating climate biases in the midlatitude North Atlantic by increasing model resolution: SST gradients and their relation to blocking and the jet |
title_full |
Mitigating climate biases in the midlatitude North Atlantic by increasing model resolution: SST gradients and their relation to blocking and the jet |
title_fullStr |
Mitigating climate biases in the midlatitude North Atlantic by increasing model resolution: SST gradients and their relation to blocking and the jet |
title_full_unstemmed |
Mitigating climate biases in the midlatitude North Atlantic by increasing model resolution: SST gradients and their relation to blocking and the jet |
title_sort |
mitigating climate biases in the midlatitude north atlantic by increasing model resolution: sst gradients and their relation to blocking and the jet |
publisher |
American Meteorological Society |
publishDate |
2022 |
url |
https://authors.library.caltech.edu/117956/ https://resolver.caltech.edu/CaltechAUTHORS:20221121-712406200.21 |
genre |
North Atlantic |
genre_facet |
North Atlantic |
op_relation |
Athanasiadis, Panos J. and Ogawa, Fumiaki and Omrani, Nour-Eddine and Keenlyside, Noel and Schiemann, Reinhard and Baker, Alexander J. and Vidale, Pier Luigi and Bellucci, Alessio and Ruggieri, Paolo and Haarsma, Rein and Roberts, Malcolm and Roberts, Chris and Novak, Lenka and Gualdi, Silvio (2022) Mitigating climate biases in the midlatitude North Atlantic by increasing model resolution: SST gradients and their relation to blocking and the jet. Journal of Climate, 35 (21). pp. 3385-3406. ISSN 0894-8755. doi:10.1175/jcli-d-21-0515.1. https://resolver.caltech.edu/CaltechAUTHORS:20221121-712406200.21 <https://resolver.caltech.edu/CaltechAUTHORS:20221121-712406200.21> |
op_doi |
https://doi.org/10.1175/jcli-d-21-0515.1 |
container_title |
Journal of Climate |
container_volume |
35 |
container_issue |
21 |
container_start_page |
6985 |
op_container_end_page |
7006 |
_version_ |
1766121348904517632 |