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Trueman CN, Artetxe-Arrate I, Kerr LA, Meijers AJS, Rooker JR, Sivankutty R, Arrizabalaga H, Belmonte A, Deguara S, Goñi N, Rodriguez-Marin E, Dettman DL, Santos MN, Karakulak FS, Tinti F, Tsukahara Y, Fraile I. Thermal sensitivity of field metabolic rate predicts differential futures for bluefin tuna juveniles across the Atlantic Ocean. Nat Commun 2023; 14:7379. [PMID: 38012173 PMCID: PMC10682405 DOI: 10.1038/s41467-023-41930-2] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/14/2023] [Accepted: 09/25/2023] [Indexed: 11/29/2023] Open
Abstract
Changing environmental temperatures impact the physiological performance of fishes, and consequently their distributions. A mechanistic understanding of the linkages between experienced temperature and the physiological response expressed within complex natural environments is often lacking, hampering efforts to project impacts especially when future conditions exceed previous experience. In this study, we use natural chemical tracers to determine the individual experienced temperatures and expressed field metabolic rates of Atlantic bluefin tuna (Thunnus thynnus) during their first year of life. Our findings reveal that the tuna exhibit a preference for temperatures 2-4 °C lower than those that maximise field metabolic rates, thereby avoiding temperatures warm enough to limit metabolic performance. Based on current IPCC projections, our results indicate that historically-important spawning and nursery grounds for bluefin tuna will become thermally limiting due to warming within the next 50 years. However, limiting global warming to below 2 °C would preserve habitat conditions in the Mediterranean Sea for this species. Our approach, which is based on field observations, provides predictions of animal performance and behaviour that are not constrained by laboratory conditions, and can be extended to any marine teleost species for which otoliths are available.
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Affiliation(s)
- Clive N Trueman
- Ocean and Earth Science, University of Southampton, Southampton, SO143ZH, UK.
| | - Iraide Artetxe-Arrate
- AZTI, Marine Research, Basque Research and Technology Alliance (BRTA), Herrera Kaia, Portualdea z/g, 20110, Pasaia, Gipuzkoa, Spain
| | - Lisa A Kerr
- University of Maine, Gulf of Maine Research Institute, 350 Commercial Street, Portland, ME, 04101, USA
| | - Andrew J S Meijers
- British Antarctic Survey, High Cross, Madingley Road, Cambridge, CB3 0ET, UK
| | - Jay R Rooker
- Department of Marine Biology, Department of Ecology and Conservation Biology, Texas A&M University, 200 Seawolf Parkway, Galveston, TX, 77554, USA
| | - Rahul Sivankutty
- British Antarctic Survey, High Cross, Madingley Road, Cambridge, CB3 0ET, UK
| | - Haritz Arrizabalaga
- AZTI, Marine Research, Basque Research and Technology Alliance (BRTA), Herrera Kaia, Portualdea z/g, 20110, Pasaia, Gipuzkoa, Spain
| | - Antonio Belmonte
- TAXON Estudios Ambientales S.L. C/Uruguay s/n, 30820, Alcantarilla, Murcia, Spain
| | - Simeon Deguara
- AquaBio Tech Ltd., Central Complex, Mosta, MST1761, Malta
| | - Nicolas Goñi
- AZTI, Marine Research, Basque Research and Technology Alliance (BRTA), Herrera Kaia, Portualdea z/g, 20110, Pasaia, Gipuzkoa, Spain
- Natural Resources Institute Finland, Itäinen Pitkäkatu 4 A, 20520, Turku, Finland
| | - Enrique Rodriguez-Marin
- Centro Oceanográfico de Santander (COST-IEO). Instituto Español de Oceanografía. Consejo Superior de Investigaciones Científicas (IEO-CSIC), C/ Severiano Ballesteros 16, 39004, Santander, Cantabria, Spain
| | - David L Dettman
- Environmental Isotope Laboratory, Dept. of Geosciences, University of Arizona, Tucson, AZ, 85721, USA
| | - Miguel Neves Santos
- Instituto Português do Mar e da Atmosfera, Olhão, Portugal. Currently at ICCAT Secretariat, Calle Corazón de Maria 8, Madrid, 28002, Spain
| | - F Saadet Karakulak
- Faculty of Aquatic Sciences, Istanbul University, Istanbul, 34134, Turkey
| | - Fausto Tinti
- Dept. Biological, Geological & Environmental Sciences, Alma Mater Studiorum - University of Bologna, via Sant'Alberto, 163 - 48123, Ravenna, Italy
| | - Yohei Tsukahara
- Fisheries Resources Institute, Japan Fisheries Research and Education Agency, Kanagawa, 236-8648, Japan
| | - Igaratza Fraile
- AZTI, Marine Research, Basque Research and Technology Alliance (BRTA), Herrera Kaia, Portualdea z/g, 20110, Pasaia, Gipuzkoa, Spain
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2
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Meijers AJS, Le Quéré C, Monteiro PMS, Sallée JB. Heat and carbon uptake in the Southern Ocean: the state of the art and future priorities. Philos Trans A Math Phys Eng Sci 2023; 381:20220071. [PMID: 37150195 PMCID: PMC10164460 DOI: 10.1098/rsta.2022.0071] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/28/2023] [Accepted: 03/28/2023] [Indexed: 05/09/2023]
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3
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Williams RG, Ceppi P, Roussenov V, Katavouta A, Meijers AJS. The role of the Southern Ocean in the global climate response to carbon emissions. Philos Trans A Math Phys Eng Sci 2023; 381:20220062. [PMID: 37150198 PMCID: PMC10164469 DOI: 10.1098/rsta.2022.0062] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/09/2023]
Abstract
The effect of the Southern Ocean on global climate change is assessed using Earth system model projections following an idealized 1% annual rise in atmospheric CO2. For this scenario, the Southern Ocean plays a significant role in sequestering heat and anthropogenic carbon, accounting for 40% ± 5% of heat uptake and 44% ± 2% of anthropogenic carbon uptake over the global ocean (with the Southern Ocean defined as south of 36°S). This Southern Ocean fraction of global heat uptake is however less than in historical scenarios with marked hemispheric contrasts in radiative forcing. For this idealized scenario, inter-model differences in global and Southern Ocean heat uptake are strongly affected by physical feedbacks, especially cloud feedbacks over the globe and surface albedo feedbacks from sea-ice loss in high latitudes, through the top-of-the-atmosphere energy balance. The ocean carbon response is similar in most models with carbon storage increasing from rising atmospheric CO2, but weakly decreasing from climate change with competing ventilation and biological contributions over the Southern Ocean. The Southern Ocean affects a global climate metric, the transient climate response to emissions, accounting for 28% of its thermal contribution through its physical climate feedbacks and heat uptake, and so affects inter-model differences in meeting warming targets. This article is part of a discussion meeting issue 'Heat and carbon uptake in the Southern Ocean: the state of the art and future priorities'.
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Affiliation(s)
- Richard G Williams
- Department of Earth, Ocean and Ecological Sciences, School of Environmental Sciences, University of Liverpool, Liverpool L69 3GP, UK
| | - Paulo Ceppi
- Department of Physics, Imperial College London, London SW7 2AZ, UK
| | - Vassil Roussenov
- Department of Earth, Ocean and Ecological Sciences, School of Environmental Sciences, University of Liverpool, Liverpool L69 3GP, UK
| | - Anna Katavouta
- Department of Earth, Ocean and Ecological Sciences, School of Environmental Sciences, University of Liverpool, Liverpool L69 3GP, UK
- National Oceanography Centre, Marine System Modelling, Proudman Building, Liverpool L69 3GP, UK
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4
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Meijers AJS, Meredith MP, Shuckburgh EF, Kent EC, Munday DR, Firing YL, King B, Smyth TJ, Leng MJ, George Nurser AJ, Hewitt HT, Povl Abrahamsen E, Weiss A, Yang M, Bell TG, Alexander Brearley J, Boland EJD, Jones DC, Josey SA, Owen RP, Grist JP, Blaker AT, Biri S, Yelland MJ, Pimm C, Zhou S, Harle J, Cornes RC. Finale: impact of the ORCHESTRA/ENCORE programmes on Southern Ocean heat and carbon understanding. Philos Trans A Math Phys Eng Sci 2023; 381:20220070. [PMID: 37150199 PMCID: PMC10164468 DOI: 10.1098/rsta.2022.0070] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/06/2022] [Accepted: 01/24/2023] [Indexed: 05/09/2023]
Abstract
The 5-year Ocean Regulation of Climate by Heat and Carbon Sequestration and Transports (ORCHESTRA) programme and its 1-year extension ENCORE (ENCORE is the National Capability ORCHESTRA Extension) was an approximately 11-million-pound programme involving seven UK research centres that finished in March 2022. The project sought to radically improve our ability to measure, understand and predict the exchange, storage and export of heat and carbon by the Southern Ocean. It achieved this through a series of milestone observational campaigns in combination with model development and analysis. Twelve cruises in the Weddell Sea and South Atlantic were undertaken, along with mooring, glider and profiler deployments and aircraft missions, all contributing to measurements of internal ocean and air-sea heat and carbon fluxes. Numerous forward and adjoint numerical experiments were developed and supported by the analysis of coupled climate models. The programme has resulted in over 100 peer-reviewed publications to date as well as significant impacts on climate assessments and policy and science coordination groups. Here, we summarize the research highlights of the programme and assess the progress achieved by ORCHESTRA/ENCORE and the questions it raises for the future. This article is part of a discussion meeting issue 'Heat and carbon uptake in the Southern Ocean: the state of the art and future priorities'.
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Affiliation(s)
| | | | - Emily F. Shuckburgh
- Department of Computer Science and Technology, University of Cambridge, William Gates Building 15 JJ Thomson Avenue, Cambridge CB3 0FD, UK
| | - Elizabeth C. Kent
- National Oceanography Centre, European Way, Southampton SO14 3ZH, UK
| | - David R. Munday
- British Antarctic Survey, High Cross, Madingley Road, CB3 0ET Cambridge, UK
| | - Yvonne L. Firing
- National Oceanography Centre, European Way, Southampton SO14 3ZH, UK
| | - Brian King
- National Oceanography Centre, European Way, Southampton SO14 3ZH, UK
| | - Tim J. Smyth
- Plymouth Marine Laboratory, Prospect Place, Plymouth PL1 3DH, UK
| | - Melanie J. Leng
- British Geological Survey, Keyworth, Nottingham NG12 5GG, UK
| | | | | | - E. Povl Abrahamsen
- British Antarctic Survey, High Cross, Madingley Road, CB3 0ET Cambridge, UK
| | - Alexandra Weiss
- British Antarctic Survey, High Cross, Madingley Road, CB3 0ET Cambridge, UK
| | - Mingxi Yang
- Plymouth Marine Laboratory, Prospect Place, Plymouth PL1 3DH, UK
| | - Thomas G. Bell
- Plymouth Marine Laboratory, Prospect Place, Plymouth PL1 3DH, UK
| | | | - Emma J. D. Boland
- British Antarctic Survey, High Cross, Madingley Road, CB3 0ET Cambridge, UK
| | - Daniel C. Jones
- British Antarctic Survey, High Cross, Madingley Road, CB3 0ET Cambridge, UK
| | - Simon A. Josey
- National Oceanography Centre, European Way, Southampton SO14 3ZH, UK
| | - Robyn P. Owen
- National Oceanography Centre, Joseph Proudman Building, 6 Brownlow Street, Liverpool L3 5DA, UK
| | - Jeremy P. Grist
- National Oceanography Centre, European Way, Southampton SO14 3ZH, UK
| | - Adam T. Blaker
- National Oceanography Centre, European Way, Southampton SO14 3ZH, UK
| | - Stavroula Biri
- National Oceanography Centre, European Way, Southampton SO14 3ZH, UK
| | | | - Ciara Pimm
- British Antarctic Survey, High Cross, Madingley Road, CB3 0ET Cambridge, UK
- Department of Earth, Ocean and Ecological Sciences, School of Environmental Sciences, University of Liverpool, Liverpool, UK
| | - Shenjie Zhou
- British Antarctic Survey, High Cross, Madingley Road, CB3 0ET Cambridge, UK
| | - James Harle
- National Oceanography Centre, European Way, Southampton SO14 3ZH, UK
| | - Richard C. Cornes
- National Oceanography Centre, European Way, Southampton SO14 3ZH, UK
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5
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Meredith MP, Povl Abrahamsen E, Alexander Haumann F, Leng MJ, Arrowsmith C, Barham M, Firing YL, King BA, Brown P, Alexander Brearley J, Meijers AJS, Sallée JB, Akhoudas C, Tarling GA. Tracing the impacts of recent rapid sea ice changes and the A68 megaberg on the surface freshwater balance of the Weddell and Scotia Seas. Philos Trans A Math Phys Eng Sci 2023; 381:20220162. [PMID: 37150196 PMCID: PMC10164467 DOI: 10.1098/rsta.2022.0162] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/09/2023]
Abstract
The Southern Ocean upper-layer freshwater balance exerts a global climatic influence by modulating density stratification and biological productivity, and hence the exchange of heat and carbon between the atmosphere and the ocean interior. It is thus important to understand and quantify the time-varying freshwater inputs, which is challenging from measurements of salinity alone. Here we use seawater oxygen isotopes from samples collected between 2016 and 2021 along a transect spanning the Scotia and northern Weddell Seas to separate the freshwater contributions from sea ice and meteoric sources. The unprecedented retreat of sea ice in 2016 is evidenced as a strong increase in sea ice melt across the northern Weddell Sea, with surface values increasing approximately two percentage points between 2016 and 2018 and column inventories increasing approximately 1 to 2 m. Surface meteoric water concentrations exceeded 4% in early 2021 close to South Georgia due to meltwater from the A68 megaberg; smaller icebergs may influence meteoric water at other times also. Both these inputs highlight the importance of a changing cryosphere for upper-ocean freshening; potential future sea ice retreats and increases in iceberg calving would enhance the impacts of these freshwater sources on the ocean and climate. This article is part of a discussion meeting issue 'Heat and carbon uptake in the Southern Ocean: the state of the art and future priorities'.
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Affiliation(s)
- Michael P Meredith
- British Antarctic Survey, High Cross, Madingley Road, Cambridge CB3 0ET, UK
| | - E Povl Abrahamsen
- British Antarctic Survey, High Cross, Madingley Road, Cambridge CB3 0ET, UK
| | - F Alexander Haumann
- British Antarctic Survey, High Cross, Madingley Road, Cambridge CB3 0ET, UK
- Atmospheric and Oceanic Sciences Program, Princeton University, NJ 08544, USA
| | - Melanie J Leng
- National Environmental Isotope Facility, British Geological Survey, NG12 5GG, UK
- School of Biosciences, University of Nottingham, Loughborough, LE12 5RD, UK
| | - Carol Arrowsmith
- National Environmental Isotope Facility, British Geological Survey, NG12 5GG, UK
| | - Mark Barham
- British Antarctic Survey, High Cross, Madingley Road, Cambridge CB3 0ET, UK
| | - Yvonne L Firing
- National Oceanography Centre, European Way, Southampton SO14 3ZH, UK
| | - Brian A King
- National Oceanography Centre, European Way, Southampton SO14 3ZH, UK
| | - Peter Brown
- National Oceanography Centre, European Way, Southampton SO14 3ZH, UK
| | | | - Andrew J S Meijers
- British Antarctic Survey, High Cross, Madingley Road, Cambridge CB3 0ET, UK
| | - Jean-Baptiste Sallée
- Sorbonne Université, CNRS/IRD/MNHN, Laboratoire d'Océanographie et du Climat Expérimentations et, Approches Numériques (LOCEAN), Paris, 75005, France
| | - Camille Akhoudas
- Sorbonne Université, CNRS/IRD/MNHN, Laboratoire d'Océanographie et du Climat Expérimentations et, Approches Numériques (LOCEAN), Paris, 75005, France
| | - Geraint A Tarling
- British Antarctic Survey, High Cross, Madingley Road, Cambridge CB3 0ET, UK
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Hyder P, Edwards JM, Allan RP, Hewitt HT, Bracegirdle TJ, Gregory JM, Wood RA, Meijers AJS, Mulcahy J, Field P, Furtado K, Bodas-Salcedo A, Williams KD, Copsey D, Josey SA, Liu C, Roberts CD, Sanchez C, Ridley J, Thorpe L, Hardiman SC, Mayer M, Berry DI, Belcher SE. Publisher Correction: Critical Southern Ocean climate model biases traced to atmospheric model cloud errors. Nat Commun 2018; 9:4105. [PMID: 30279569 PMCID: PMC6168563 DOI: 10.1038/s41467-018-06662-8] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Grants] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022] Open
Abstract
'In the original HTML version of this Article, ref.12 was incorrectly cited in the first sentence of the first paragraph of the Introduction. The correct citation is ref. 2. This has now been corrected in the HTML version of the Article; the PDF version was correct at the time of publication.'
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Affiliation(s)
| | | | - Richard P Allan
- Department of Meteorology, University of Reading, PO Box 243, Whiteknights Campus Earley Gate, Reading, RG6 6BB, UK
- National Centre for Earth Observations (NCEO), University of Reading, PO Box 243, Whiteknights Campus Earley Gate, Reading, RG6 6BB, UK
| | | | | | - Jonathan M Gregory
- Met Office Hadley Centre, FitzRoy Road, Exeter, UK
- National Centre for Atmospheric Sciences (NCAS), University of Reading, PO Box 243, Whiteknights Campus Earley Gate, Reading, RG6 6BB, UK
| | | | - Andrew J S Meijers
- British Antarctic Survey, High Cross, Madingley Road, Cambridge, CB3 0ET, UK
| | - Jane Mulcahy
- Met Office Hadley Centre, FitzRoy Road, Exeter, UK
| | - Paul Field
- Met Office Hadley Centre, FitzRoy Road, Exeter, UK
- School of Earth and Environment, University of Leeds, Leeds, LS2 9JT, UK
| | | | | | | | - Dan Copsey
- Met Office Hadley Centre, FitzRoy Road, Exeter, UK
| | - Simon A Josey
- National Oceanography Centre, European Way, Southampton, SO14 3ZH, UK
| | - Chunlei Liu
- Department of Meteorology, University of Reading, PO Box 243, Whiteknights Campus Earley Gate, Reading, RG6 6BB, UK
- National Centre for Earth Observations (NCEO), University of Reading, PO Box 243, Whiteknights Campus Earley Gate, Reading, RG6 6BB, UK
| | | | | | - Jeff Ridley
- Met Office Hadley Centre, FitzRoy Road, Exeter, UK
| | - Livia Thorpe
- Met Office Hadley Centre, FitzRoy Road, Exeter, UK
| | | | - Michael Mayer
- Department of Meteorology and Geophysics, University of Vienna, Althanstraße 14, Vienna, 1090, Austria
| | - David I Berry
- National Oceanography Centre, European Way, Southampton, SO14 3ZH, UK
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7
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Hyder P, Edwards JM, Allan RP, Hewitt HT, Bracegirdle TJ, Gregory JM, Wood RA, Meijers AJS, Mulcahy J, Field P, Furtado K, Bodas-Salcedo A, Williams KD, Copsey D, Josey SA, Liu C, Roberts CD, Sanchez C, Ridley J, Thorpe L, Hardiman SC, Mayer M, Berry DI, Belcher SE. Critical Southern Ocean climate model biases traced to atmospheric model cloud errors. Nat Commun 2018; 9:3625. [PMID: 30206222 PMCID: PMC6134029 DOI: 10.1038/s41467-018-05634-2] [Citation(s) in RCA: 72] [Impact Index Per Article: 12.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/19/2017] [Accepted: 07/18/2018] [Indexed: 11/17/2022] Open
Abstract
The Southern Ocean is a pivotal component of the global climate system yet it is poorly represented in climate models, with significant biases in upper-ocean temperatures, clouds and winds. Combining Atmospheric and Coupled Model Inter-comparison Project (AMIP5/CMIP5) simulations, with observations and equilibrium heat budget theory, we show that across the CMIP5 ensemble variations in sea surface temperature biases in the 40-60°S Southern Ocean are primarily caused by AMIP5 atmospheric model net surface flux bias variations, linked to cloud-related short-wave errors. Equilibration of the biases involves local coupled sea surface temperature bias feedbacks onto the surface heat flux components. In combination with wind feedbacks, these biases adversely modify upper-ocean thermal structure. Most AMIP5 atmospheric models that exhibit small net heat flux biases appear to achieve this through compensating errors. We demonstrate that targeted developments to cloud-related parameterisations provide a route to better represent the Southern Ocean in climate models and projections.
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Affiliation(s)
| | | | - Richard P Allan
- Department of Meteorology, University of Reading, PO Box 243, Whiteknights Campus Earley Gate, Reading, RG6 6BB, UK
- National Centre for Earth Observations (NCEO), University of Reading, PO Box 243, Whiteknights Campus Earley Gate, Reading, RG6 6BB, UK
| | | | | | - Jonathan M Gregory
- Met Office Hadley Centre, FitzRoy Road, Exeter, UK
- National Centre for Atmospheric Sciences (NCAS), University of Reading, PO Box 243, Whiteknights Campus Earley Gate, Reading, RG6 6BB, UK
| | | | - Andrew J S Meijers
- British Antarctic Survey, High Cross, Madingley Road, Cambridge, CB3 0ET, UK
| | - Jane Mulcahy
- Met Office Hadley Centre, FitzRoy Road, Exeter, UK
| | - Paul Field
- Met Office Hadley Centre, FitzRoy Road, Exeter, UK
- School of Earth and Environment, University of Leeds, Leeds, LS2 9JT, UK
| | | | | | | | - Dan Copsey
- Met Office Hadley Centre, FitzRoy Road, Exeter, UK
| | - Simon A Josey
- National Oceanography Centre, European Way, Southampton, SO14 3ZH, UK
| | - Chunlei Liu
- Department of Meteorology, University of Reading, PO Box 243, Whiteknights Campus Earley Gate, Reading, RG6 6BB, UK
- National Centre for Earth Observations (NCEO), University of Reading, PO Box 243, Whiteknights Campus Earley Gate, Reading, RG6 6BB, UK
| | | | | | - Jeff Ridley
- Met Office Hadley Centre, FitzRoy Road, Exeter, UK
| | - Livia Thorpe
- Met Office Hadley Centre, FitzRoy Road, Exeter, UK
| | | | - Michael Mayer
- Department of Meteorology and Geophysics, University of Vienna, Althanstraße 14, Vienna, 1090, Austria
| | - David I Berry
- National Oceanography Centre, European Way, Southampton, SO14 3ZH, UK
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Naveira Garabato AC, MacGilchrist GA, Brown PJ, Evans DG, Meijers AJS, Zika JD. High-latitude ocean ventilation and its role in Earth's climate transitions. Philos Trans A Math Phys Eng Sci 2017; 376:rsta.2017.0324. [PMID: 28784714 DOI: 10.1098/rsta.2017.0324] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Accepted: 03/23/2018] [Indexed: 05/13/2023]
Abstract
The processes regulating ocean ventilation at high latitudes are re-examined based on a range of observations spanning all scales of ocean circulation, from the centimetre scales of turbulence to the basin scales of gyres. It is argued that high-latitude ocean ventilation is controlled by mechanisms that differ in fundamental ways from those that set the overturning circulation. This is contrary to the assumption of broad equivalence between the two that is commonly adopted in interpreting the role of the high-latitude oceans in Earth's climate transitions. Illustrations of how recognizing this distinction may change our view of the ocean's role in the climate system are offered.This article is part of the themed issue 'Ocean ventilation and deoxygenation in a warming world'.
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Affiliation(s)
| | | | | | - D Gwyn Evans
- Ocean and Earth Science, University of Southampton, National Oceanography Centre, Southampton, UK
| | | | - Jan D Zika
- School of Mathematics and Statistics, University of New South Wales, Sydney, Australia
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9
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Naveira Garabato AC, MacGilchrist GA, Brown PJ, Evans DG, Meijers AJS, Zika JD. High-latitude ocean ventilation and its role in Earth's climate transitions. Philos Trans A Math Phys Eng Sci 2017; 375:rsta.2016.0324. [PMID: 28784714 PMCID: PMC5559419 DOI: 10.1098/rsta.2016.0324] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Accepted: 06/05/2017] [Indexed: 05/13/2023]
Abstract
The processes regulating ocean ventilation at high latitudes are re-examined based on a range of observations spanning all scales of ocean circulation, from the centimetre scales of turbulence to the basin scales of gyres. It is argued that high-latitude ocean ventilation is controlled by mechanisms that differ in fundamental ways from those that set the overturning circulation. This is contrary to the assumption of broad equivalence between the two that is commonly adopted in interpreting the role of the high-latitude oceans in Earth's climate transitions. Illustrations of how recognizing this distinction may change our view of the ocean's role in the climate system are offered.This article is part of the themed issue 'Ocean ventilation and deoxygenation in a warming world'.
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Affiliation(s)
| | | | | | - D Gwyn Evans
- Ocean and Earth Science, University of Southampton, National Oceanography Centre, Southampton, UK
| | | | - Jan D Zika
- School of Mathematics and Statistics, University of New South Wales, Sydney, Australia
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10
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Abstract
The Southern Ocean is an important part of the global climate system, but its complex coupled nature makes both its present state and its response to projected future climate forcing difficult to model. Clear trends in wind, sea-ice extent and ocean properties emerged from multi-model intercomparison in the Coupled Model Intercomparison Project phase 3 (CMIP3). Here, we review recent analyses of the historical and projected wind, sea ice, circulation and bulk properties of the Southern Ocean in the updated Coupled Model Intercomparison Project phase 5 (CMIP5) ensemble. Improvements to the models include higher resolutions, more complex and better-tuned parametrizations of ocean mixing, and improved biogeochemical cycles and atmospheric chemistry. CMIP5 largely reproduces the findings of CMIP3, but with smaller inter-model spreads and biases. By the end of the twenty-first century, mid-latitude wind stresses increase and shift polewards. All water masses warm, and intermediate waters freshen, while bottom waters increase in salinity. Surface mixed layers shallow, warm and freshen, whereas sea ice decreases. The upper overturning circulation intensifies, whereas bottom water formation is reduced. Significant disagreement exists between models for the response of the Antarctic Circumpolar Current strength, for reasons that are as yet unclear.
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Affiliation(s)
- A J S Meijers
- British Antarctic Survey, High Cross, Madingley Road, Cambridge CB3 0ET, UK
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