North Atlantic deep water formation and AMOC in CMIP5 models
Deep water formation in climate models is indicative of their ability to simulate future ocean circulation, carbon and heat uptake, and sea level rise. Present-day temperature, salinity, sea ice concentration and ocean transport in the North Atlantic subpolar gyre and Nordic Seas from 23 CMIP5 (Clim...
Published in: | Ocean Science |
---|---|
Main Author: | |
Format: | Text |
Language: | English |
Published: |
2018
|
Subjects: | |
Online Access: | https://doi.org/10.5194/os-13-609-2017 https://os.copernicus.org/articles/13/609/2017/ |
id |
ftcopernicus:oai:publications.copernicus.org:os56917 |
---|---|
record_format |
openpolar |
spelling |
ftcopernicus:oai:publications.copernicus.org:os56917 2023-05-15T14:54:17+02:00 North Atlantic deep water formation and AMOC in CMIP5 models Heuzé, Céline 2018-09-17 application/pdf https://doi.org/10.5194/os-13-609-2017 https://os.copernicus.org/articles/13/609/2017/ eng eng doi:10.5194/os-13-609-2017 https://os.copernicus.org/articles/13/609/2017/ eISSN: 1812-0792 Text 2018 ftcopernicus https://doi.org/10.5194/os-13-609-2017 2020-07-20T16:23:40Z Deep water formation in climate models is indicative of their ability to simulate future ocean circulation, carbon and heat uptake, and sea level rise. Present-day temperature, salinity, sea ice concentration and ocean transport in the North Atlantic subpolar gyre and Nordic Seas from 23 CMIP5 (Climate Model Intercomparison Project, phase 5) models are compared with observations to assess the biases, causes and consequences of North Atlantic deep convection in models. The majority of models convect too deep, over too large an area, too often and too far south. Deep convection occurs at the sea ice edge and is most realistic in models with accurate sea ice extent, mostly those using the CICE model. Half of the models convect in response to local cooling or salinification of the surface waters; only a third have a dynamic relationship between freshwater coming from the Arctic and deep convection. The models with the most intense deep convection have the warmest deep waters, due to a redistribution of heat through the water column. For the majority of models, the variability of the Atlantic Meridional Overturning Circulation (AMOC) is explained by the volumes of deep water produced in the subpolar gyre and Nordic Seas up to 2 years before. In turn, models with the strongest AMOC have the largest heat export to the Arctic. Understanding the dynamical drivers of deep convection and AMOC in models is hence key to realistically forecasting Arctic oceanic warming and its consequences for the global ocean circulation, cryosphere and marine life. Text Arctic Nordic Seas North Atlantic Deep Water North Atlantic Sea ice Copernicus Publications: E-Journals Arctic Ocean Science 13 4 609 622 |
institution |
Open Polar |
collection |
Copernicus Publications: E-Journals |
op_collection_id |
ftcopernicus |
language |
English |
description |
Deep water formation in climate models is indicative of their ability to simulate future ocean circulation, carbon and heat uptake, and sea level rise. Present-day temperature, salinity, sea ice concentration and ocean transport in the North Atlantic subpolar gyre and Nordic Seas from 23 CMIP5 (Climate Model Intercomparison Project, phase 5) models are compared with observations to assess the biases, causes and consequences of North Atlantic deep convection in models. The majority of models convect too deep, over too large an area, too often and too far south. Deep convection occurs at the sea ice edge and is most realistic in models with accurate sea ice extent, mostly those using the CICE model. Half of the models convect in response to local cooling or salinification of the surface waters; only a third have a dynamic relationship between freshwater coming from the Arctic and deep convection. The models with the most intense deep convection have the warmest deep waters, due to a redistribution of heat through the water column. For the majority of models, the variability of the Atlantic Meridional Overturning Circulation (AMOC) is explained by the volumes of deep water produced in the subpolar gyre and Nordic Seas up to 2 years before. In turn, models with the strongest AMOC have the largest heat export to the Arctic. Understanding the dynamical drivers of deep convection and AMOC in models is hence key to realistically forecasting Arctic oceanic warming and its consequences for the global ocean circulation, cryosphere and marine life. |
format |
Text |
author |
Heuzé, Céline |
spellingShingle |
Heuzé, Céline North Atlantic deep water formation and AMOC in CMIP5 models |
author_facet |
Heuzé, Céline |
author_sort |
Heuzé, Céline |
title |
North Atlantic deep water formation and AMOC in CMIP5 models |
title_short |
North Atlantic deep water formation and AMOC in CMIP5 models |
title_full |
North Atlantic deep water formation and AMOC in CMIP5 models |
title_fullStr |
North Atlantic deep water formation and AMOC in CMIP5 models |
title_full_unstemmed |
North Atlantic deep water formation and AMOC in CMIP5 models |
title_sort |
north atlantic deep water formation and amoc in cmip5 models |
publishDate |
2018 |
url |
https://doi.org/10.5194/os-13-609-2017 https://os.copernicus.org/articles/13/609/2017/ |
geographic |
Arctic |
geographic_facet |
Arctic |
genre |
Arctic Nordic Seas North Atlantic Deep Water North Atlantic Sea ice |
genre_facet |
Arctic Nordic Seas North Atlantic Deep Water North Atlantic Sea ice |
op_source |
eISSN: 1812-0792 |
op_relation |
doi:10.5194/os-13-609-2017 https://os.copernicus.org/articles/13/609/2017/ |
op_doi |
https://doi.org/10.5194/os-13-609-2017 |
container_title |
Ocean Science |
container_volume |
13 |
container_issue |
4 |
container_start_page |
609 |
op_container_end_page |
622 |
_version_ |
1766326003564544000 |