CMIP5 Model Intercomparison of Freshwater Budget and Circulation in the North Atlantic
International audience The subpolar North Atlantic is a center of variability of ocean properties, wind stress curl, and air–sea exchanges. Observations and hindcast simulations suggest that from the early 1970s to the mid-1990s the subpolar gyre became fresher while the gyre and meridional circulat...
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Online Access: | https://hal.science/hal-01128173 https://doi.org/10.1175/JCLI-D-12-00700.1 |
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ftunivbrest:oai:HAL:hal-01128173v1 2024-04-28T08:29:50+00:00 CMIP5 Model Intercomparison of Freshwater Budget and Circulation in the North Atlantic Deshayes, Julie Curry, Ruth Msadek, Rym ICEMASA University of Cape Town Laboratoire de physique des océans (LPO) Institut de Recherche pour le Développement (IRD)-Institut Français de Recherche pour l'Exploitation de la Mer (IFREMER)-Université de Brest (UBO)-Centre National de la Recherche Scientifique (CNRS) NOAA Geophysical Fluid Dynamics Laboratory (GFDL) National Oceanic and Atmospheric Administration (NOAA) 2014-05 https://hal.science/hal-01128173 https://doi.org/10.1175/JCLI-D-12-00700.1 en eng HAL CCSD American Meteorological Society info:eu-repo/semantics/altIdentifier/doi/10.1175/JCLI-D-12-00700.1 hal-01128173 https://hal.science/hal-01128173 doi:10.1175/JCLI-D-12-00700.1 IRD: fdi:010062266 ISSN: 0894-8755 EISSN: 1520-0442 Journal of Climate https://hal.science/hal-01128173 Journal of Climate, 2014, 27 (9), pp.3298-3317. ⟨10.1175/JCLI-D-12-00700.1⟩ Climate models Freshwater PAGO Atmosphere-ocean interaction North Atlantic Oscillation Climate variability Model comparison [SDU.STU.OC]Sciences of the Universe [physics]/Earth Sciences/Oceanography [SDU.OCEAN]Sciences of the Universe [physics]/Ocean Atmosphere info:eu-repo/semantics/article Journal articles 2014 ftunivbrest https://doi.org/10.1175/JCLI-D-12-00700.1 2024-04-10T23:51:25Z International audience The subpolar North Atlantic is a center of variability of ocean properties, wind stress curl, and air–sea exchanges. Observations and hindcast simulations suggest that from the early 1970s to the mid-1990s the subpolar gyre became fresher while the gyre and meridional circulations intensified. This is opposite to the relationship of freshening causing a weakened circulation, most often reproduced by climate models. The authors hypothesize that both these configurations exist but dominate on different time scales: a fresher subpolar gyre when the circulation is more intense, at interannual frequencies (configuration A), and a saltier subpolar gyre when the circulation is more intense, at longer periods (configuration B). Rather than going into the detail of the mechanisms sustaining each configuration, the authors’ objective is to identify which configuration dominates and to test whether this depends on frequency, in preindustrial control runs of five climate models from phase 5 of the Coupled Model Intercomparison Project (CMIP5). To this end, the authors have developed a novel intercomparison method that enables analysis of freshwater budget and circulation changes in a physical perspective that overcomes model specificities. Lag correlations and a cross-spectral analysis between freshwater content changes and circulation indices validate the authors’ hypothesis, as configuration A is only visible at interannual frequencies while configuration B is mostly visible at decadal and longer periods, suggesting that the driving role of salinity on the circulation depends on frequency. Overall, this analysis underscores the large differences among state-of-the-art climate models in their representations of the North Atlantic freshwater budget. Article in Journal/Newspaper North Atlantic North Atlantic oscillation Université de Bretagne Occidentale: HAL Journal of Climate 27 9 3298 3317 |
institution |
Open Polar |
collection |
Université de Bretagne Occidentale: HAL |
op_collection_id |
ftunivbrest |
language |
English |
topic |
Climate models Freshwater PAGO Atmosphere-ocean interaction North Atlantic Oscillation Climate variability Model comparison [SDU.STU.OC]Sciences of the Universe [physics]/Earth Sciences/Oceanography [SDU.OCEAN]Sciences of the Universe [physics]/Ocean Atmosphere |
spellingShingle |
Climate models Freshwater PAGO Atmosphere-ocean interaction North Atlantic Oscillation Climate variability Model comparison [SDU.STU.OC]Sciences of the Universe [physics]/Earth Sciences/Oceanography [SDU.OCEAN]Sciences of the Universe [physics]/Ocean Atmosphere Deshayes, Julie Curry, Ruth Msadek, Rym CMIP5 Model Intercomparison of Freshwater Budget and Circulation in the North Atlantic |
topic_facet |
Climate models Freshwater PAGO Atmosphere-ocean interaction North Atlantic Oscillation Climate variability Model comparison [SDU.STU.OC]Sciences of the Universe [physics]/Earth Sciences/Oceanography [SDU.OCEAN]Sciences of the Universe [physics]/Ocean Atmosphere |
description |
International audience The subpolar North Atlantic is a center of variability of ocean properties, wind stress curl, and air–sea exchanges. Observations and hindcast simulations suggest that from the early 1970s to the mid-1990s the subpolar gyre became fresher while the gyre and meridional circulations intensified. This is opposite to the relationship of freshening causing a weakened circulation, most often reproduced by climate models. The authors hypothesize that both these configurations exist but dominate on different time scales: a fresher subpolar gyre when the circulation is more intense, at interannual frequencies (configuration A), and a saltier subpolar gyre when the circulation is more intense, at longer periods (configuration B). Rather than going into the detail of the mechanisms sustaining each configuration, the authors’ objective is to identify which configuration dominates and to test whether this depends on frequency, in preindustrial control runs of five climate models from phase 5 of the Coupled Model Intercomparison Project (CMIP5). To this end, the authors have developed a novel intercomparison method that enables analysis of freshwater budget and circulation changes in a physical perspective that overcomes model specificities. Lag correlations and a cross-spectral analysis between freshwater content changes and circulation indices validate the authors’ hypothesis, as configuration A is only visible at interannual frequencies while configuration B is mostly visible at decadal and longer periods, suggesting that the driving role of salinity on the circulation depends on frequency. Overall, this analysis underscores the large differences among state-of-the-art climate models in their representations of the North Atlantic freshwater budget. |
author2 |
ICEMASA University of Cape Town Laboratoire de physique des océans (LPO) Institut de Recherche pour le Développement (IRD)-Institut Français de Recherche pour l'Exploitation de la Mer (IFREMER)-Université de Brest (UBO)-Centre National de la Recherche Scientifique (CNRS) NOAA Geophysical Fluid Dynamics Laboratory (GFDL) National Oceanic and Atmospheric Administration (NOAA) |
format |
Article in Journal/Newspaper |
author |
Deshayes, Julie Curry, Ruth Msadek, Rym |
author_facet |
Deshayes, Julie Curry, Ruth Msadek, Rym |
author_sort |
Deshayes, Julie |
title |
CMIP5 Model Intercomparison of Freshwater Budget and Circulation in the North Atlantic |
title_short |
CMIP5 Model Intercomparison of Freshwater Budget and Circulation in the North Atlantic |
title_full |
CMIP5 Model Intercomparison of Freshwater Budget and Circulation in the North Atlantic |
title_fullStr |
CMIP5 Model Intercomparison of Freshwater Budget and Circulation in the North Atlantic |
title_full_unstemmed |
CMIP5 Model Intercomparison of Freshwater Budget and Circulation in the North Atlantic |
title_sort |
cmip5 model intercomparison of freshwater budget and circulation in the north atlantic |
publisher |
HAL CCSD |
publishDate |
2014 |
url |
https://hal.science/hal-01128173 https://doi.org/10.1175/JCLI-D-12-00700.1 |
genre |
North Atlantic North Atlantic oscillation |
genre_facet |
North Atlantic North Atlantic oscillation |
op_source |
ISSN: 0894-8755 EISSN: 1520-0442 Journal of Climate https://hal.science/hal-01128173 Journal of Climate, 2014, 27 (9), pp.3298-3317. ⟨10.1175/JCLI-D-12-00700.1⟩ |
op_relation |
info:eu-repo/semantics/altIdentifier/doi/10.1175/JCLI-D-12-00700.1 hal-01128173 https://hal.science/hal-01128173 doi:10.1175/JCLI-D-12-00700.1 IRD: fdi:010062266 |
op_doi |
https://doi.org/10.1175/JCLI-D-12-00700.1 |
container_title |
Journal of Climate |
container_volume |
27 |
container_issue |
9 |
container_start_page |
3298 |
op_container_end_page |
3317 |
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1797587911536803840 |