Articles | Volume 17, issue 5
https://doi.org/10.5194/os-17-1177-2021
© Author(s) 2021. This work is distributed under
the Creative Commons Attribution 4.0 License.
the Creative Commons Attribution 4.0 License.
https://doi.org/10.5194/os-17-1177-2021
© Author(s) 2021. This work is distributed under
the Creative Commons Attribution 4.0 License.
the Creative Commons Attribution 4.0 License.
Research article
| 
02 Sep 2021
Research article |
| 02 Sep 2021
| 02 Sep 2021
Regional imprints of changes in the Atlantic Meridional Overturning Circulation in the eddy-rich ocean model VIKING20X
GEOMAR Helmholtz Centre for Ocean Research Kiel, Kiel, Germany
Christian-Albrechts Universität zu Kiel, Kiel, Germany
Franziska U. Schwarzkopf
GEOMAR Helmholtz Centre for Ocean Research Kiel, Kiel, Germany
Klaus Getzlaff
GEOMAR Helmholtz Centre for Ocean Research Kiel, Kiel, Germany
Siren Rühs
GEOMAR Helmholtz Centre for Ocean Research Kiel, Kiel, Germany
Torge Martin
GEOMAR Helmholtz Centre for Ocean Research Kiel, Kiel, Germany
Markus Scheinert
GEOMAR Helmholtz Centre for Ocean Research Kiel, Kiel, Germany
Tobias Schulzki
GEOMAR Helmholtz Centre for Ocean Research Kiel, Kiel, Germany
Patricia Handmann
GEOMAR Helmholtz Centre for Ocean Research Kiel, Kiel, Germany
Rebecca Hummels
GEOMAR Helmholtz Centre for Ocean Research Kiel, Kiel, Germany
Claus W. Böning
GEOMAR Helmholtz Centre for Ocean Research Kiel, Kiel, Germany
Christian-Albrechts Universität zu Kiel, Kiel, Germany
Related authors
Léo C. Aroucha, Joke F. Lübbecke, Peter Brandt, Franziska U. Schwarzkopf, and Arne Biastoch
EGUsphere, https://doi.org/10.5194/egusphere-2024-3320, https://doi.org/10.5194/egusphere-2024-3320, 2024
Short summary
Short summary
The West African coastal region sustains highly productive fisheries and marine ecosystems influenced by sea surface temperature. We use oceanic models to show that the freshwater input from land to ocean strengthens a surface northward (southward) coastal current north (south) of the Congo river mouth, promoting a transfer of cooler (warmer) waters to north (south) of the Congo discharge location. We highlight the significant impact of river discharge on ocean temperatures and circulation.
Hendrik Grosselindemann, Frederic S. Castruccio, Gokhan Danabasoglu, and Arne Biastoch
EGUsphere, https://doi.org/10.5194/egusphere-2024-2288, https://doi.org/10.5194/egusphere-2024-2288, 2024
Short summary
Short summary
This study investigates Agulhas Leakage and examines its role in the global ocean circulation. It utilises a high-resolution earth system model and a pre-industrial climate to look at the response of Agulhas Leakage to the wind field and the Atlantic Meridional Overturning Circulation (AMOC) as well as its evolution under climate change. Agulhas Leakage influences the stability of the AMOC whose possible collapse would impact the global climate on the Northern Hemisphere.
Kristin Burmeister, Franziska U. Schwarzkopf, Willi Rath, Arne Biastoch, Peter Brandt, Joke F. Lübbecke, and Mark Inall
Ocean Sci., 20, 307–339, https://doi.org/10.5194/os-20-307-2024, https://doi.org/10.5194/os-20-307-2024, 2024
Short summary
Short summary
We apply two different forcing products to a high-resolution ocean model to investigate their impact on the simulated upper-current field in the tropical Atlantic. Where possible, we compare the simulated results to long-term observations. We find large discrepancies between the two simulations regarding the wind and current fields. We propose that long-term observations, once they have reached a critical length, need to be used to test the quality of wind-driven simulations.
Torge Martin and Arne Biastoch
Ocean Sci., 19, 141–167, https://doi.org/10.5194/os-19-141-2023, https://doi.org/10.5194/os-19-141-2023, 2023
Short summary
Short summary
How is the ocean affected by continued Greenland Ice Sheet mass loss? We show in a systematic set of model experiments that atmospheric feedback needs to be accounted for as the large-scale ocean circulation is more than twice as sensitive to the meltwater otherwise. Coastal winds, boundary currents, and ocean eddies play a key role in redistributing the meltwater. Eddy paramterization helps the coarse simulation to perform better in the Labrador Sea but not in the North Atlantic Current region.
Alan D. Fox, Patricia Handmann, Christina Schmidt, Neil Fraser, Siren Rühs, Alejandra Sanchez-Franks, Torge Martin, Marilena Oltmanns, Clare Johnson, Willi Rath, N. Penny Holliday, Arne Biastoch, Stuart A. Cunningham, and Igor Yashayaev
Ocean Sci., 18, 1507–1533, https://doi.org/10.5194/os-18-1507-2022, https://doi.org/10.5194/os-18-1507-2022, 2022
Short summary
Short summary
Observations of the eastern subpolar North Atlantic in the 2010s show exceptional freshening and cooling of the upper ocean, peaking in 2016 with the lowest salinities recorded for 120 years. Using results from a high-resolution ocean model, supported by observations, we propose that the leading cause is reduced surface cooling over the preceding decade in the Labrador Sea, leading to increased outflow of less dense water and so to freshening and cooling of the eastern subpolar North Atlantic.
Jörg Fröhle, Patricia V. K. Handmann, and Arne Biastoch
Ocean Sci., 18, 1431–1450, https://doi.org/10.5194/os-18-1431-2022, https://doi.org/10.5194/os-18-1431-2022, 2022
Short summary
Short summary
Three deep-water masses pass the southern exit of the Labrador Sea. Usually they are defined by explicit density intervals linked to the formation region. We evaluate this relation in an ocean model by backtracking the paths the water follows for 40 years: 48 % densify without contact to the atmosphere, 24 % densify in contact with the atmosphere, and 19 % are from the Nordic Seas. All three contribute to a similar density range at 53° N with weak specific formation location characteristics.
Takaya Uchida, Julien Le Sommer, Charles Stern, Ryan P. Abernathey, Chris Holdgraf, Aurélie Albert, Laurent Brodeau, Eric P. Chassignet, Xiaobiao Xu, Jonathan Gula, Guillaume Roullet, Nikolay Koldunov, Sergey Danilov, Qiang Wang, Dimitris Menemenlis, Clément Bricaud, Brian K. Arbic, Jay F. Shriver, Fangli Qiao, Bin Xiao, Arne Biastoch, René Schubert, Baylor Fox-Kemper, William K. Dewar, and Alan Wallcraft
Geosci. Model Dev., 15, 5829–5856, https://doi.org/10.5194/gmd-15-5829-2022, https://doi.org/10.5194/gmd-15-5829-2022, 2022
Short summary
Short summary
Ocean and climate scientists have used numerical simulations as a tool to examine the ocean and climate system since the 1970s. Since then, owing to the continuous increase in computational power and advances in numerical methods, we have been able to simulate increasing complex phenomena. However, the fidelity of the simulations in representing the phenomena remains a core issue in the ocean science community. Here we propose a cloud-based framework to inter-compare and assess such simulations.
Jens Zinke, Takaaki K. Watanabe, Siren Rühs, Miriam Pfeiffer, Stefan Grab, Dieter Garbe-Schönberg, and Arne Biastoch
Clim. Past, 18, 1453–1474, https://doi.org/10.5194/cp-18-1453-2022, https://doi.org/10.5194/cp-18-1453-2022, 2022
Short summary
Short summary
Salinity is an important and integrative measure of changes to the water cycle steered by changes to the balance between rainfall and evaporation and by vertical and horizontal movements of water parcels by ocean currents. However, salinity measurements in our oceans are extremely sparse. To fill this gap, we have developed a 334-year coral record of seawater oxygen isotopes that reflects salinity changes in the globally important Agulhas Current system and reveals its main oceanic drivers.
Ioana Ivanciu, Katja Matthes, Arne Biastoch, Sebastian Wahl, and Jan Harlaß
Weather Clim. Dynam., 3, 139–171, https://doi.org/10.5194/wcd-3-139-2022, https://doi.org/10.5194/wcd-3-139-2022, 2022
Short summary
Short summary
Greenhouse gas concentrations continue to increase, while the Antarctic ozone hole is expected to recover during the twenty-first century. We separate the effects of ozone recovery and of greenhouse gases on the Southern Hemisphere atmospheric and oceanic circulation, and we find that ozone recovery is generally reducing the impact of greenhouse gases, with the exception of certain regions of the stratosphere during spring, where the two effects reinforce each other.
Christina Schmidt, Franziska U. Schwarzkopf, Siren Rühs, and Arne Biastoch
Ocean Sci., 17, 1067–1080, https://doi.org/10.5194/os-17-1067-2021, https://doi.org/10.5194/os-17-1067-2021, 2021
Short summary
Short summary
We estimate Agulhas leakage, water flowing from the Indian Ocean to the South Atlantic, in an ocean model with two different tools. The mean transport, variability and trend of Agulhas leakage is simulated comparably with both tools, emphasising the robustness of our method. If the experiments are designed differently, the mean transport of Agulhas leakage is altered, but not the trend. Agulhas leakage waters cool and become less salty south of Africa resulting in a density increase.
Ioana Ivanciu, Katja Matthes, Sebastian Wahl, Jan Harlaß, and Arne Biastoch
Atmos. Chem. Phys., 21, 5777–5806, https://doi.org/10.5194/acp-21-5777-2021, https://doi.org/10.5194/acp-21-5777-2021, 2021
Short summary
Short summary
The Antarctic ozone hole has driven substantial dynamical changes in the Southern Hemisphere atmosphere over the past decades. This study separates the historical impacts of ozone depletion from those of rising levels of greenhouse gases and investigates how these impacts are captured in two types of climate models: one using interactive atmospheric chemistry and one prescribing the CMIP6 ozone field. The effects of ozone depletion are more pronounced in the model with interactive chemistry.
Josefine Maas, Susann Tegtmeier, Yue Jia, Birgit Quack, Jonathan V. Durgadoo, and Arne Biastoch
Atmos. Chem. Phys., 21, 4103–4121, https://doi.org/10.5194/acp-21-4103-2021, https://doi.org/10.5194/acp-21-4103-2021, 2021
Short summary
Short summary
Cooling-water disinfection at coastal power plants is a known source of atmospheric bromoform. A large source of anthropogenic bromoform is the industrial regions in East Asia. In current bottom-up flux estimates, these anthropogenic emissions are missing, underestimating the global air–sea flux of bromoform. With transport simulations, we show that by including anthropogenic bromoform from cooling-water treatment, the bottom-up flux estimates significantly improve in East and Southeast Asia.
Katja Matthes, Arne Biastoch, Sebastian Wahl, Jan Harlaß, Torge Martin, Tim Brücher, Annika Drews, Dana Ehlert, Klaus Getzlaff, Fritz Krüger, Willi Rath, Markus Scheinert, Franziska U. Schwarzkopf, Tobias Bayr, Hauke Schmidt, and Wonsun Park
Geosci. Model Dev., 13, 2533–2568, https://doi.org/10.5194/gmd-13-2533-2020, https://doi.org/10.5194/gmd-13-2533-2020, 2020
Short summary
Short summary
A new Earth system model, the Flexible Ocean and Climate Infrastructure (FOCI), is introduced, consisting of a high-top atmosphere, an ocean model, sea-ice and land surface model components. A unique feature of FOCI is the ability to explicitly resolve small-scale oceanic features, for example, the Agulhas Current and the Gulf Stream. It allows to study the evolution of the climate system on regional and seasonal to (multi)decadal scales and bridges the gap to coarse-resolution climate models.
Nele Tim, Eduardo Zorita, Kay-Christian Emeis, Franziska U. Schwarzkopf, Arne Biastoch, and Birgit Hünicke
Earth Syst. Dynam., 10, 847–858, https://doi.org/10.5194/esd-10-847-2019, https://doi.org/10.5194/esd-10-847-2019, 2019
Short summary
Short summary
Our study reveals that the latitudinal position and intensity of Southern Hemisphere trades and westerlies are correlated. In the last decades the westerlies have shifted poleward and intensified. Furthermore, the latitudinal shifts and intensity of the trades and westerlies impact the sea surface temperatures around southern Africa and in the South Benguela upwelling region. The future development of wind stress depends on the strength of greenhouse gas forcing.
Franziska U. Schwarzkopf, Arne Biastoch, Claus W. Böning, Jérôme Chanut, Jonathan V. Durgadoo, Klaus Getzlaff, Jan Harlaß, Jan K. Rieck, Christina Roth, Markus M. Scheinert, and René Schubert
Geosci. Model Dev., 12, 3329–3355, https://doi.org/10.5194/gmd-12-3329-2019, https://doi.org/10.5194/gmd-12-3329-2019, 2019
Short summary
Short summary
A family of nested global ocean general circulation model configurations, the INALT family, has been established with resolutions of 1/10°, 1/20° and 1/60° in the South Atlantic and western Indian oceans, covering the greater Agulhas Current (AC) system. The INALT family provides a consistent set of configurations that allows to address eddy dynamics in the AC system and their impact on the large-scale ocean circulation.
Josefine Maas, Susann Tegtmeier, Birgit Quack, Arne Biastoch, Jonathan V. Durgadoo, Siren Rühs, Stephan Gollasch, and Matej David
Ocean Sci., 15, 891–904, https://doi.org/10.5194/os-15-891-2019, https://doi.org/10.5194/os-15-891-2019, 2019
Short summary
Short summary
In a large-scale analysis, the spread of disinfection by-products from oxidative ballast water treatment is investigated, with a focus on Southeast Asia where major ports are located. Halogenated compounds such as bromoform (CHBr3) are produced in the ballast water and, once emitted into the environment, can participate in ozone depletion. Anthropogenic bromoform is rapidly emitted into the atmosphere and can locally double around large ports. A large-scale impact cannot be found.
Siren Rühs, Franziska U. Schwarzkopf, Sabrina Speich, and Arne Biastoch
Ocean Sci., 15, 489–512, https://doi.org/10.5194/os-15-489-2019, https://doi.org/10.5194/os-15-489-2019, 2019
Short summary
Short summary
We revisit the sources for the upper limb of the overturning circulation in the South Atlantic by tracking fluid particles in a high-resolution ocean model. Our results suggest that the upper limb’s transport is dominantly supplied by waters with Indian Ocean origin, but the contribution of waters with Pacific origin is substantially larger than previously estimated with coarse-resolution models. Yet, a large part of upper limb waters obtains thermohaline properties within the South Atlantic.
D. Le Bars, J. V. Durgadoo, H. A. Dijkstra, A. Biastoch, and W. P. M. De Ruijter
Ocean Sci., 10, 601–609, https://doi.org/10.5194/os-10-601-2014, https://doi.org/10.5194/os-10-601-2014, 2014
Léo C. Aroucha, Joke F. Lübbecke, Peter Brandt, Franziska U. Schwarzkopf, and Arne Biastoch
EGUsphere, https://doi.org/10.5194/egusphere-2024-3320, https://doi.org/10.5194/egusphere-2024-3320, 2024
Short summary
Short summary
The West African coastal region sustains highly productive fisheries and marine ecosystems influenced by sea surface temperature. We use oceanic models to show that the freshwater input from land to ocean strengthens a surface northward (southward) coastal current north (south) of the Congo river mouth, promoting a transfer of cooler (warmer) waters to north (south) of the Congo discharge location. We highlight the significant impact of river discharge on ocean temperatures and circulation.
Hendrik Grosselindemann, Frederic S. Castruccio, Gokhan Danabasoglu, and Arne Biastoch
EGUsphere, https://doi.org/10.5194/egusphere-2024-2288, https://doi.org/10.5194/egusphere-2024-2288, 2024
Short summary
Short summary
This study investigates Agulhas Leakage and examines its role in the global ocean circulation. It utilises a high-resolution earth system model and a pre-industrial climate to look at the response of Agulhas Leakage to the wind field and the Atlantic Meridional Overturning Circulation (AMOC) as well as its evolution under climate change. Agulhas Leakage influences the stability of the AMOC whose possible collapse would impact the global climate on the Northern Hemisphere.
Swantje Bastin, Aleksei Koldunov, Florian Schütte, Oliver Gutjahr, Marta Agnieszka Mrozowska, Tim Fischer, Radomyra Shevchenko, Arjun Kumar, Nikolay Koldunov, Helmuth Haak, Nils Brüggemann, Rebecca Hummels, Mia Sophie Specht, Johann Jungclaus, Sergey Danilov, Marcus Dengler, and Markus Jochum
EGUsphere, https://doi.org/10.5194/egusphere-2024-2281, https://doi.org/10.5194/egusphere-2024-2281, 2024
Short summary
Short summary
Vertical mixing is an important process e.g. for tropical sea surface temperature, but cannot be resolved by ocean models. Comparisons of mixing schemes and settings have usually been done with a single model, sometimes yielding conflicting results. We systematically compare two widely used schemes, TKE and KPP, with different parameter settings, in two different ocean models, and show that most effects from mixing scheme parameter changes are model dependent.
Siren Rühs, Ton van den Bremer, Emanuela Clementi, Michael C. Denes, Aimie Moulin, and Erik van Sebille
EGUsphere, https://doi.org/10.5194/egusphere-2024-1002, https://doi.org/10.5194/egusphere-2024-1002, 2024
Short summary
Short summary
Simulating the transport of floating particles on the ocean surface is crucial for solving many societal issues. Here, we investigate how the representation of wind-generated surface waves impacts particle transport simulations. We find that different wave-driven processes can alter the transport patterns, and that commonly adopted approximations are not always adequate. This implies that ideally coupled ocean-wave models should be used for surface particle transport simulations.
Kristin Burmeister, Franziska U. Schwarzkopf, Willi Rath, Arne Biastoch, Peter Brandt, Joke F. Lübbecke, and Mark Inall
Ocean Sci., 20, 307–339, https://doi.org/10.5194/os-20-307-2024, https://doi.org/10.5194/os-20-307-2024, 2024
Short summary
Short summary
We apply two different forcing products to a high-resolution ocean model to investigate their impact on the simulated upper-current field in the tropical Atlantic. Where possible, we compare the simulated results to long-term observations. We find large discrepancies between the two simulations regarding the wind and current fields. We propose that long-term observations, once they have reached a critical length, need to be used to test the quality of wind-driven simulations.
Neil C. Swart, Torge Martin, Rebecca Beadling, Jia-Jia Chen, Christopher Danek, Matthew H. England, Riccardo Farneti, Stephen M. Griffies, Tore Hattermann, Judith Hauck, F. Alexander Haumann, André Jüling, Qian Li, John Marshall, Morven Muilwijk, Andrew G. Pauling, Ariaan Purich, Inga J. Smith, and Max Thomas
Geosci. Model Dev., 16, 7289–7309, https://doi.org/10.5194/gmd-16-7289-2023, https://doi.org/10.5194/gmd-16-7289-2023, 2023
Short summary
Short summary
Current climate models typically do not include full representation of ice sheets. As the climate warms and the ice sheets melt, they add freshwater to the ocean. This freshwater can influence climate change, for example by causing more sea ice to form. In this paper we propose a set of experiments to test the influence of this missing meltwater from Antarctica using multiple different climate models.
Torge Martin and Arne Biastoch
Ocean Sci., 19, 141–167, https://doi.org/10.5194/os-19-141-2023, https://doi.org/10.5194/os-19-141-2023, 2023
Short summary
Short summary
How is the ocean affected by continued Greenland Ice Sheet mass loss? We show in a systematic set of model experiments that atmospheric feedback needs to be accounted for as the large-scale ocean circulation is more than twice as sensitive to the meltwater otherwise. Coastal winds, boundary currents, and ocean eddies play a key role in redistributing the meltwater. Eddy paramterization helps the coarse simulation to perform better in the Labrador Sea but not in the North Atlantic Current region.
Alan D. Fox, Patricia Handmann, Christina Schmidt, Neil Fraser, Siren Rühs, Alejandra Sanchez-Franks, Torge Martin, Marilena Oltmanns, Clare Johnson, Willi Rath, N. Penny Holliday, Arne Biastoch, Stuart A. Cunningham, and Igor Yashayaev
Ocean Sci., 18, 1507–1533, https://doi.org/10.5194/os-18-1507-2022, https://doi.org/10.5194/os-18-1507-2022, 2022
Short summary
Short summary
Observations of the eastern subpolar North Atlantic in the 2010s show exceptional freshening and cooling of the upper ocean, peaking in 2016 with the lowest salinities recorded for 120 years. Using results from a high-resolution ocean model, supported by observations, we propose that the leading cause is reduced surface cooling over the preceding decade in the Labrador Sea, leading to increased outflow of less dense water and so to freshening and cooling of the eastern subpolar North Atlantic.
Jörg Fröhle, Patricia V. K. Handmann, and Arne Biastoch
Ocean Sci., 18, 1431–1450, https://doi.org/10.5194/os-18-1431-2022, https://doi.org/10.5194/os-18-1431-2022, 2022
Short summary
Short summary
Three deep-water masses pass the southern exit of the Labrador Sea. Usually they are defined by explicit density intervals linked to the formation region. We evaluate this relation in an ocean model by backtracking the paths the water follows for 40 years: 48 % densify without contact to the atmosphere, 24 % densify in contact with the atmosphere, and 19 % are from the Nordic Seas. All three contribute to a similar density range at 53° N with weak specific formation location characteristics.
Takaya Uchida, Julien Le Sommer, Charles Stern, Ryan P. Abernathey, Chris Holdgraf, Aurélie Albert, Laurent Brodeau, Eric P. Chassignet, Xiaobiao Xu, Jonathan Gula, Guillaume Roullet, Nikolay Koldunov, Sergey Danilov, Qiang Wang, Dimitris Menemenlis, Clément Bricaud, Brian K. Arbic, Jay F. Shriver, Fangli Qiao, Bin Xiao, Arne Biastoch, René Schubert, Baylor Fox-Kemper, William K. Dewar, and Alan Wallcraft
Geosci. Model Dev., 15, 5829–5856, https://doi.org/10.5194/gmd-15-5829-2022, https://doi.org/10.5194/gmd-15-5829-2022, 2022
Short summary
Short summary
Ocean and climate scientists have used numerical simulations as a tool to examine the ocean and climate system since the 1970s. Since then, owing to the continuous increase in computational power and advances in numerical methods, we have been able to simulate increasing complex phenomena. However, the fidelity of the simulations in representing the phenomena remains a core issue in the ocean science community. Here we propose a cloud-based framework to inter-compare and assess such simulations.
Jens Zinke, Takaaki K. Watanabe, Siren Rühs, Miriam Pfeiffer, Stefan Grab, Dieter Garbe-Schönberg, and Arne Biastoch
Clim. Past, 18, 1453–1474, https://doi.org/10.5194/cp-18-1453-2022, https://doi.org/10.5194/cp-18-1453-2022, 2022
Short summary
Short summary
Salinity is an important and integrative measure of changes to the water cycle steered by changes to the balance between rainfall and evaporation and by vertical and horizontal movements of water parcels by ocean currents. However, salinity measurements in our oceans are extremely sparse. To fill this gap, we have developed a 334-year coral record of seawater oxygen isotopes that reflects salinity changes in the globally important Agulhas Current system and reveals its main oceanic drivers.
Ioana Ivanciu, Katja Matthes, Arne Biastoch, Sebastian Wahl, and Jan Harlaß
Weather Clim. Dynam., 3, 139–171, https://doi.org/10.5194/wcd-3-139-2022, https://doi.org/10.5194/wcd-3-139-2022, 2022
Short summary
Short summary
Greenhouse gas concentrations continue to increase, while the Antarctic ozone hole is expected to recover during the twenty-first century. We separate the effects of ozone recovery and of greenhouse gases on the Southern Hemisphere atmospheric and oceanic circulation, and we find that ozone recovery is generally reducing the impact of greenhouse gases, with the exception of certain regions of the stratosphere during spring, where the two effects reinforce each other.
Jannes Koelling, Dariia Atamanchuk, Johannes Karstensen, Patricia Handmann, and Douglas W. R. Wallace
Biogeosciences, 19, 437–454, https://doi.org/10.5194/bg-19-437-2022, https://doi.org/10.5194/bg-19-437-2022, 2022
Short summary
Short summary
In this study, we investigate oxygen variability in the deep western boundary current in the Labrador Sea from multiyear moored records. We estimate that about half of the oxygen taken up in the interior Labrador Sea by air–sea gas exchange during deep water formation is exported southward the same year. Our results underline the complexity of the oxygen uptake and export in the Labrador Sea and highlight the important role this region plays in supplying oxygen to the deep ocean.
Patrick Wagner and Claus W. Böning
Ocean Sci., 17, 1473–1487, https://doi.org/10.5194/os-17-1473-2021, https://doi.org/10.5194/os-17-1473-2021, 2021
Short summary
Short summary
We characterized the pattern and magnitude of decadal sea-level variability in the Australasian Mediterranean Sea by using high-resolution ocean models. Our results suggest low-frequency ENSO variations and PDO-related changes as a primary source of variability. Sensitivity experiments indicate that anomalies are primarily driven by wind stress fluctuation but are also amplified by local heat and freshwater fluxes. Intrinsic variability is relevant in the South China Sea.
Patrick Wagner, Markus Scheinert, and Claus W. Böning
Ocean Sci., 17, 1103–1113, https://doi.org/10.5194/os-17-1103-2021, https://doi.org/10.5194/os-17-1103-2021, 2021
Short summary
Short summary
We analyse the importance of local heat and freshwater fluxes for sea level variability in the tropical Pacific on interannual to decadal timescales by using a global ocean model. Our results suggest that they amplify sea level variability in the eastern part of the basin and dampen it in the central and western part of the domain. We demonstrate that the oceanic response allows local sea level anomalies to propagate zonally which enables remote effects of local heat and freshwater fluxes.
Christina Schmidt, Franziska U. Schwarzkopf, Siren Rühs, and Arne Biastoch
Ocean Sci., 17, 1067–1080, https://doi.org/10.5194/os-17-1067-2021, https://doi.org/10.5194/os-17-1067-2021, 2021
Short summary
Short summary
We estimate Agulhas leakage, water flowing from the Indian Ocean to the South Atlantic, in an ocean model with two different tools. The mean transport, variability and trend of Agulhas leakage is simulated comparably with both tools, emphasising the robustness of our method. If the experiments are designed differently, the mean transport of Agulhas leakage is altered, but not the trend. Agulhas leakage waters cool and become less salty south of Africa resulting in a density increase.
Ioana Ivanciu, Katja Matthes, Sebastian Wahl, Jan Harlaß, and Arne Biastoch
Atmos. Chem. Phys., 21, 5777–5806, https://doi.org/10.5194/acp-21-5777-2021, https://doi.org/10.5194/acp-21-5777-2021, 2021
Short summary
Short summary
The Antarctic ozone hole has driven substantial dynamical changes in the Southern Hemisphere atmosphere over the past decades. This study separates the historical impacts of ozone depletion from those of rising levels of greenhouse gases and investigates how these impacts are captured in two types of climate models: one using interactive atmospheric chemistry and one prescribing the CMIP6 ozone field. The effects of ozone depletion are more pronounced in the model with interactive chemistry.
Josefine Maas, Susann Tegtmeier, Yue Jia, Birgit Quack, Jonathan V. Durgadoo, and Arne Biastoch
Atmos. Chem. Phys., 21, 4103–4121, https://doi.org/10.5194/acp-21-4103-2021, https://doi.org/10.5194/acp-21-4103-2021, 2021
Short summary
Short summary
Cooling-water disinfection at coastal power plants is a known source of atmospheric bromoform. A large source of anthropogenic bromoform is the industrial regions in East Asia. In current bottom-up flux estimates, these anthropogenic emissions are missing, underestimating the global air–sea flux of bromoform. With transport simulations, we show that by including anthropogenic bromoform from cooling-water treatment, the bottom-up flux estimates significantly improve in East and Southeast Asia.
Josefine Herrford, Peter Brandt, Torsten Kanzow, Rebecca Hummels, Moacyr Araujo, and Jonathan V. Durgadoo
Ocean Sci., 17, 265–284, https://doi.org/10.5194/os-17-265-2021, https://doi.org/10.5194/os-17-265-2021, 2021
Short summary
Short summary
The Atlantic Meridional Overturning Circulation (AMOC) is an important component of the climate system. Understanding its structure and variability is a key priority for many scientists. Here, we present the first estimate of AMOC variations for the tropical South Atlantic from the TRACOS array at 11° S. Over the observed period, the AMOC was dominated by seasonal variability. We investigate the respective mechanisms with an ocean model and find that different wind-forced waves play a big role.
Hiroyuki Tsujino, L. Shogo Urakawa, Stephen M. Griffies, Gokhan Danabasoglu, Alistair J. Adcroft, Arthur E. Amaral, Thomas Arsouze, Mats Bentsen, Raffaele Bernardello, Claus W. Böning, Alexandra Bozec, Eric P. Chassignet, Sergey Danilov, Raphael Dussin, Eleftheria Exarchou, Pier Giuseppe Fogli, Baylor Fox-Kemper, Chuncheng Guo, Mehmet Ilicak, Doroteaciro Iovino, Who M. Kim, Nikolay Koldunov, Vladimir Lapin, Yiwen Li, Pengfei Lin, Keith Lindsay, Hailong Liu, Matthew C. Long, Yoshiki Komuro, Simon J. Marsland, Simona Masina, Aleksi Nummelin, Jan Klaus Rieck, Yohan Ruprich-Robert, Markus Scheinert, Valentina Sicardi, Dmitry Sidorenko, Tatsuo Suzuki, Hiroaki Tatebe, Qiang Wang, Stephen G. Yeager, and Zipeng Yu
Geosci. Model Dev., 13, 3643–3708, https://doi.org/10.5194/gmd-13-3643-2020, https://doi.org/10.5194/gmd-13-3643-2020, 2020
Short summary
Short summary
The OMIP-2 framework for global ocean–sea-ice model simulations is assessed by comparing multi-model means from 11 CMIP6-class global ocean–sea-ice models calculated separately for the OMIP-1 and OMIP-2 simulations. Many features are very similar between OMIP-1 and OMIP-2 simulations, and yet key improvements in transitioning from OMIP-1 to OMIP-2 are also identified. Thus, the present assessment justifies that future ocean–sea-ice model development and analysis studies use the OMIP-2 framework.
Katja Matthes, Arne Biastoch, Sebastian Wahl, Jan Harlaß, Torge Martin, Tim Brücher, Annika Drews, Dana Ehlert, Klaus Getzlaff, Fritz Krüger, Willi Rath, Markus Scheinert, Franziska U. Schwarzkopf, Tobias Bayr, Hauke Schmidt, and Wonsun Park
Geosci. Model Dev., 13, 2533–2568, https://doi.org/10.5194/gmd-13-2533-2020, https://doi.org/10.5194/gmd-13-2533-2020, 2020
Short summary
Short summary
A new Earth system model, the Flexible Ocean and Climate Infrastructure (FOCI), is introduced, consisting of a high-top atmosphere, an ocean model, sea-ice and land surface model components. A unique feature of FOCI is the ability to explicitly resolve small-scale oceanic features, for example, the Agulhas Current and the Gulf Stream. It allows to study the evolution of the climate system on regional and seasonal to (multi)decadal scales and bridges the gap to coarse-resolution climate models.
Nele Tim, Eduardo Zorita, Kay-Christian Emeis, Franziska U. Schwarzkopf, Arne Biastoch, and Birgit Hünicke
Earth Syst. Dynam., 10, 847–858, https://doi.org/10.5194/esd-10-847-2019, https://doi.org/10.5194/esd-10-847-2019, 2019
Short summary
Short summary
Our study reveals that the latitudinal position and intensity of Southern Hemisphere trades and westerlies are correlated. In the last decades the westerlies have shifted poleward and intensified. Furthermore, the latitudinal shifts and intensity of the trades and westerlies impact the sea surface temperatures around southern Africa and in the South Benguela upwelling region. The future development of wind stress depends on the strength of greenhouse gas forcing.
Franziska U. Schwarzkopf, Arne Biastoch, Claus W. Böning, Jérôme Chanut, Jonathan V. Durgadoo, Klaus Getzlaff, Jan Harlaß, Jan K. Rieck, Christina Roth, Markus M. Scheinert, and René Schubert
Geosci. Model Dev., 12, 3329–3355, https://doi.org/10.5194/gmd-12-3329-2019, https://doi.org/10.5194/gmd-12-3329-2019, 2019
Short summary
Short summary
A family of nested global ocean general circulation model configurations, the INALT family, has been established with resolutions of 1/10°, 1/20° and 1/60° in the South Atlantic and western Indian oceans, covering the greater Agulhas Current (AC) system. The INALT family provides a consistent set of configurations that allows to address eddy dynamics in the AC system and their impact on the large-scale ocean circulation.
Josefine Maas, Susann Tegtmeier, Birgit Quack, Arne Biastoch, Jonathan V. Durgadoo, Siren Rühs, Stephan Gollasch, and Matej David
Ocean Sci., 15, 891–904, https://doi.org/10.5194/os-15-891-2019, https://doi.org/10.5194/os-15-891-2019, 2019
Short summary
Short summary
In a large-scale analysis, the spread of disinfection by-products from oxidative ballast water treatment is investigated, with a focus on Southeast Asia where major ports are located. Halogenated compounds such as bromoform (CHBr3) are produced in the ballast water and, once emitted into the environment, can participate in ozone depletion. Anthropogenic bromoform is rapidly emitted into the atmosphere and can locally double around large ports. A large-scale impact cannot be found.
Siren Rühs, Franziska U. Schwarzkopf, Sabrina Speich, and Arne Biastoch
Ocean Sci., 15, 489–512, https://doi.org/10.5194/os-15-489-2019, https://doi.org/10.5194/os-15-489-2019, 2019
Short summary
Short summary
We revisit the sources for the upper limb of the overturning circulation in the South Atlantic by tracking fluid particles in a high-resolution ocean model. Our results suggest that the upper limb’s transport is dominantly supplied by waters with Indian Ocean origin, but the contribution of waters with Pacific origin is substantially larger than previously estimated with coarse-resolution models. Yet, a large part of upper limb waters obtains thermohaline properties within the South Atlantic.
Olaf Duteil, Andreas Oschlies, and Claus W. Böning
Biogeosciences, 15, 7111–7126, https://doi.org/10.5194/bg-15-7111-2018, https://doi.org/10.5194/bg-15-7111-2018, 2018
Short summary
Short summary
Oxygen-depleted regions of the Pacific Ocean are currently expanding, which is threatening marine habitats. Based on numerical simulations, we show that the decrease in the intensity of the trade winds and the subsequent slowdown of the oceanic currents lead to a reduction in oxygen supply. Our study suggests that the prevailing positive conditions of the Pacific Decadal Oscillation since 1975, a major source of natural variability, may explain a significant part of the current deoxygenation.
Rafael Abel, Claus W. Böning, Richard J. Greatbatch, Helene T. Hewitt, and Malcolm J. Roberts
Ocean Sci. Discuss., https://doi.org/10.5194/os-2017-24, https://doi.org/10.5194/os-2017-24, 2017
Revised manuscript not accepted
Short summary
Short summary
In coupled global atmosphere ocean models a feedback from ocean surface currents to atmospheric winds was found. Surface winds are energized by about 30 % of the ocean currents. We were able to implement this feedback in uncoupled ocean models which results in a realistic surface flux coupling. Due to changes in the dissipation the kinetic energy of the time-variable flow is increased up to 10 % when this feedback is implemented. Implementation in other models should be straightforward.
Stephen M. Griffies, Gokhan Danabasoglu, Paul J. Durack, Alistair J. Adcroft, V. Balaji, Claus W. Böning, Eric P. Chassignet, Enrique Curchitser, Julie Deshayes, Helge Drange, Baylor Fox-Kemper, Peter J. Gleckler, Jonathan M. Gregory, Helmuth Haak, Robert W. Hallberg, Patrick Heimbach, Helene T. Hewitt, David M. Holland, Tatiana Ilyina, Johann H. Jungclaus, Yoshiki Komuro, John P. Krasting, William G. Large, Simon J. Marsland, Simona Masina, Trevor J. McDougall, A. J. George Nurser, James C. Orr, Anna Pirani, Fangli Qiao, Ronald J. Stouffer, Karl E. Taylor, Anne Marie Treguier, Hiroyuki Tsujino, Petteri Uotila, Maria Valdivieso, Qiang Wang, Michael Winton, and Stephen G. Yeager
Geosci. Model Dev., 9, 3231–3296, https://doi.org/10.5194/gmd-9-3231-2016, https://doi.org/10.5194/gmd-9-3231-2016, 2016
Short summary
Short summary
The Ocean Model Intercomparison Project (OMIP) aims to provide a framework for evaluating, understanding, and improving the ocean and sea-ice components of global climate and earth system models contributing to the Coupled Model Intercomparison Project Phase 6 (CMIP6). This document defines OMIP and details a protocol both for simulating global ocean/sea-ice models and for analysing their output.
H. Dietze, U. Löptien, and K. Getzlaff
Geosci. Model Dev., 7, 1713–1731, https://doi.org/10.5194/gmd-7-1713-2014, https://doi.org/10.5194/gmd-7-1713-2014, 2014
D. Le Bars, J. V. Durgadoo, H. A. Dijkstra, A. Biastoch, and W. P. M. De Ruijter
Ocean Sci., 10, 601–609, https://doi.org/10.5194/os-10-601-2014, https://doi.org/10.5194/os-10-601-2014, 2014
Related subject area
Approach: Numerical Models | Properties and processes: Overturning circulation | Depth range: All Depths | Geographical range: Deep Seas: North Atlantic | Challenges: Oceans and climate
Seasonal overturning variability in the eastern North Atlantic subpolar gyre: a Lagrangian perspective
On the ocean's response to enhanced Greenland runoff in model experiments: relevance of mesoscale dynamics and atmospheric coupling
Oliver John Tooth, Helen Louise Johnson, Chris Wilson, and Dafydd Gwyn Evans
Ocean Sci., 19, 769–791, https://doi.org/10.5194/os-19-769-2023, https://doi.org/10.5194/os-19-769-2023, 2023
Short summary
Short summary
This study uses the trajectories of water parcels traced within an ocean model simulation to identify the pathways responsible for the seasonal cycle of dense water formation (overturning) in the eastern subpolar North Atlantic. We show that overturning seasonality is due to the fastest water parcels circulating within the eastern basins in less than 8.5 months. Slower pathways set the average strength of overturning in this region since water parcels cannot escape intense wintertime cooling.
Torge Martin and Arne Biastoch
Ocean Sci., 19, 141–167, https://doi.org/10.5194/os-19-141-2023, https://doi.org/10.5194/os-19-141-2023, 2023
Short summary
Short summary
How is the ocean affected by continued Greenland Ice Sheet mass loss? We show in a systematic set of model experiments that atmospheric feedback needs to be accounted for as the large-scale ocean circulation is more than twice as sensitive to the meltwater otherwise. Coastal winds, boundary currents, and ocean eddies play a key role in redistributing the meltwater. Eddy paramterization helps the coarse simulation to perform better in the Labrador Sea but not in the North Atlantic Current region.
Cited articles
Aksamit, N. O., Sapsis, T., and Haller, G.: Machine-Learning Mesoscale and
Submesoscale Surface Dynamics from Lagrangian Ocean Drifter Trajectories, J.
Phys. Oceanogr., 50, 1179–1196, https://doi.org/10.1175/JPO-D-19-0238.1, 2020. a
Amante, C. and Eakins, B.: ETOPO1 1 Arc-Minute Global Relief Model:
Procedures, Data Sources and Analysis, NOAA Tech. Memo. NESDIS NGDC-24,
p. 19, https://doi.org/10.1594/PANGAEA.769615, 2009. a
Arakawa, A. and Hsu, Y.-J. G.: Energy Conserving and Potential-Enstrophy
Dissipating Schemes for the Shallow Water Equations, Mon. Weather Rev., 118, 1960–1969,
1990. a
Baltazar-Soares, M., Biastoch, A., Harrod, C., Hanel, R., Marohn, L., Prigge,
E., Evans, D., Bodles, K., Behrens, E., Böning, C. W., and Eizaguirre,
C.: Recruitment collapse and population structure of the european eel shaped
by local ocean current dynamics, Curr. Biol., 24, 104–108,
https://doi.org/10.1016/j.cub.2013.11.031, 2014. a
Bamber, J. L., Tedstone, A. J., King, M. D., Howat, I. M., Enderlin, E. M.,
van den Broeke, M. R., and Noel, B.: Land Ice Freshwater Budget of the
Arctic and North Atlantic Oceans: 1. Data, Methods, and Results, J. Geophys.
Res.-Ocean., 123, 1827–1837, https://doi.org/10.1002/2017JC013605, 2018. a
Barnier, B., Madec, G., Penduff, T., Molines, J.-M., Treguier, A.-M.,
Le Sommer, J., Beckmann, A., Biastoch, A., Böning, C., Dengg, J., Derval,
C., Durand, E., Gulev, S., Remy, E., Talandier, C., Theetten, S., Maltrud,
M., McClean, J., and De Cuevas, B.: Impact of partial steps and momentum
advection schemes in a global ocean circulation model at eddy-permitting
resolution, Ocean Dynam., 56, 543–567, 2006. a, b, c
Behrens, E., Biastoch, A., and Böning, C. W.: Spurious AMOC trends in
global ocean sea-ice models related to subarctic freshwater forcing, Ocean
Model., 69, 39–49, https://doi.org/10.1016/j.ocemod.2013.05.004, 2013. a, b, c, d
Behrens, E., Våge, K., Harden, B., Biastoch, A., and Böning, C. W.:
Composition and variability of the Denmark Strait Overflow Water in a
high-resolution numerical model hindcast simulation, J. Geophys. Res.-Ocean., 122, 2830–2846, https://doi.org/10.1002/2016JC012158, 2017. a
Berx, B., Hansen, B., Østerhus, S., Larsen, K. M., Sherwin, T., and Jochumsen, K.: Combining in situ measurements and altimetry to estimate volume, heat and salt transport variability through the Faroe–Shetland Channel, Ocean Sci., 9, 639–654, https://doi.org/10.5194/os-9-639-2013, 2013. a
Biastoch, A., Böning, C. W., Getzlaff, J., Molines, J.-M., and Madec, G.:
Causes of interannual-decadal variability in the meridional overturning
circulation of the mid-latitude North Atlantic Ocean, J. Clim., 21,
6599–6615, https://doi.org/10.1175/2008JCLI2404.1, 2008a. a, b, c, d
Biastoch, A., Böning, C. W., and Lutjeharms, J. R.: Agulhas leakage
dynamics affects decadal variability in Atlantic overturning circulation,
Nature, 456, 489–492, https://doi.org/10.1038/nature07426, 2008b. a
Biastoch, A., Böning, C. W., Schwarzkopf, F. U., and Lutjeharms, J.
R. E.: Increase in Agulhas leakage due to poleward shift of Southern
Hemisphere westerlies, Nature, 462, 495–498, https://doi.org/10.1038/nature08519,
2009. a
Biastoch, A, Schwarzkopf, F. U., Getzlaff, K., Rühs, S., Martin, T., Scheinert, M., Schulzki, T., Handmann, P., Hummels, R., and Claus W. Böning: Supplementary Data to Biastoch et al. (2021): Regional Imprints of Changes in the Atlantic Meridional Overturning Circulation in the Eddy-rich Ocean Model VIKING20X [data set], available at: https://hdl.handle.net/20.500.12085/a8f98a1a-473f-11ea-a036-c81f66eb46c3 (last access: 26 August 2021), 2021. a
Biló, T. C. and Johns, W. E.: Interior Pathways of Labrador Sea Water in
the North Atlantic From the Argo Perspective, Geophys. Res. Lett., 46,
3340–3348, https://doi.org/10.1029/2018GL081439, 2019. a
Bingham, R. J., Hughes, C. W., Roussenov, V., and Williams, R. G.: Meridional
coherence of the North Atlantic meridional overturning circulation, Geophys.
Res. Lett., 34, 23, https://doi.org/10.1029/2007GL031731, 2007. a
Blanke, B. and Delecluse, P.: Variability of the Tropical Atlantic Ocean
Simulated by a General Circulation Model with Two Different Mixed-Layer
Physics, J. Phys. Oceanogr., 23, 1363–1388, 1993. a
Blindheim, J. and Osterhus, S.: The Nordic Seas, main oceanographic features, in :The Nordic Seas: An Integrated Perspective, Vol. 158,
Geophysical Monograph Series, 158, 11–37, 2005. a
Böning, C. W., Scheinert, M., Dengg, J., Biastoch, A., and Funk, A.:
Decadal variability of subpolar gyre transport and its reverberation in the
North Atlantic overturning, Geophys. Res. Lett., 33, 21,
https://doi.org/10.1029/2006GL026906, 2006. a, b, c
Böning, C. W., Behrens, E., Biastoch, A., Getzlaff, K., and Bamber,
J. L.: Emerging impact of Greenland meltwater on deepwater formation in the
North Atlantic Ocean, Nat. Geosci., 9, 523–527, https://doi.org/10.1038/ngeo2740,
2016. a, b, c, d
Bourdallé-Badie, R. and Treguier, A.: A climatology of runoff for the
global ocean-ice model ORCA025, Mercator-Ocean reference M0O-RP-425-365-MER,
2006. a
Bower, A., Lozier, S., Biastoch, A., Drouin, K., Foukal, N., Furey, H.,
Lankhorst, M., Rühs, S., and Zou, S.: Lagrangian Views of the Pathways
of the Atlantic Meridional Overturning Circulation, J. Geophys. Res.-Ocean.,
124, 5313–5335, https://doi.org/10.1029/2019JC015014, 2019. a
Bower, A. S., Lozier, M. S., Gary, S. F., and Böning, C. W.: Interior
pathways of the North Atlantic meridional overturning circulation., Nature,
459, 243–247, https://doi.org/10.1038/nature07979, 2009. a
Brandt, P., Schott, F. A., Funk, A., and Martins, C. S.: Seasonal to
interannual variability of the eddy field in the Labrador Sea from satellite
altimetry, J. Geophys. Res., 109, C02028, https://doi.org/10.1029/2002JC001551, 2004. a
Breckenfelder, T., Rhein, M., Roessler, A., Böning, C. W., Biastoch, A.,
Behrens, E., and Mertens, C.: Flow paths and variability of the North
Atlantic Current: A comparison of observations and a high-resolution model,
J. Geophys. Res.-Ocean., 122, 2686–2708, https://doi.org/10.1002/2016JC012444, 2017. a, b, c
Breusing, C., Biastoch, A., Drews, A., Metaxas, A., Jollivet, D., Vrijenhoek,
R. C., Bayer, T., Melzner, F., Sayavedra, L., Petersen, J. M., Dubilier, N.,
Schilhabel, M. B., Rosenstiel, P., and Reusch, T. B. H.: Biophysical and
Population Genetic Models Predict the Presence of “Phantom” Stepping
Stones Connecting Mid-Atlantic Ridge Vent Ecosystems, Curr. Biol., 26,
2257–2267, https://doi.org/10.1016/j.cub.2016.06.062, 2016. a
Brodeau, L., Barnier, B., Treguier, A. M., Penduff, T., and Gulev, S.: An
ERA40-based atmospheric forcing for global ocean circulation models, Ocean
Model., 31, 88–104, https://doi.org/10.1016/j.ocemod.2009.10.005, 2010. a
Buckley, M. W. and Marshall, J.: Observations, inferences, and mechanisms of
the Atlantic Meridional Overturning Circulation: A review, Rev. Geophys.,
54, 5–63, https://doi.org/10.1002/2015RG000493, 2016. a
Caesar, L., Rahmstorf, S., Robinson, A., Feulner, G., and Saba, V.: Observed
fingerprint of a weakening Atlantic Ocean overturning circulation, Nature,
556, 191–196, https://doi.org/10.1038/s41586-018-0006-5, 2018. a
Caesar, L., McCarthy, G. D., Thornalley, D. J. R., Cahill, N., and Rahmstorf,
S.: Current Atlantic Meridional Overturning Circulation weakest in last
millennium, Nat. Geosci., 14, 118–120, https://doi.org/10.1038/s41561-021-00699-z, 2021. a
Chanut, J., Barnier, B., Large, W., Debreu, L., Penduff, T., Molines, J. M.,
and Mathiot, P.: Mesoscale eddies in the Labrador Sea and their contribution
to convection and restratification, J. Phys. Oceanogr., 38, 1617–1643,
https://doi.org/10.1175/2008JPO3485.1, 2008. a
Chassignet, E. P. and Xu, X.: Impact of horizontal resolution (
Colombo, P., Barnier, B., Penduff, T., Chanut, J., Deshayes, J., Molines,
J. M., Le Sommer, J., Verezemskaya, P., Gulev, S., and Treguier, A. M.:
Representation of the Denmark Strait overflow in a z-coordinate eddying
configuration of the NEMO (v3.6) ocean model: Resolution and parameter
impacts, Geosci. Model Dev., 13, 3347–3371, https://doi.org/10.5194/gmd-13-3347-2020,
2020. a
Danabasoglu, G., Yeager, S. G., Bailey, D., Behrens, E., Bentsen, M., Bi, D.,
Biastoch, A., Böning, C., Bozec, A., Canuto, V. M., Cassou, C.,
Chassignet, E., Coward, A. C., Danilov, S., Diansky, N., Drange, H., Farneti,
R., Fernandez, E., Fogli, P. G., Forget, G., Fujii, Y., Griffies, S. M.,
Gusev, A., Heimbach, P., Howard, A., Jung, T., Kelley, M., Large, W. G.,
Leboissetier, A., Lu, J., Madec, G., Marsland, S. J., Masina, S., Navarra,
A., George Nurser, A. J., Pirani, A., y Mélia, D. S., Samuels, B. L.,
Scheinert, M., Sidorenko, D., Treguier, A. M., Tsujino, H., Uotila, P.,
Valcke, S., Voldoire, A., and Wang, Q.: North Atlantic simulations in
Coordinated Ocean-ice Reference Experiments phase II (CORE-II), Part I: Mean
states, Ocean Model., 73, 76–107, https://doi.org/10.1016/j.ocemod.2013.10.005, 2014. a, b, c
Danabasoglu, G., Yeager, S. G., Kim, W. M., Behrens, E., Bentsen, M., Bi, D.,
Biastoch, A., Bleck, R., Böning, C., Bozec, A., Canuto, V. M., Cassou,
C., Chassignet, E., Coward, A. C., Danilov, S., Diansky, N., Drange, H.,
Farneti, R., Fernandez, E., Fogli, P. G., Forget, G., Fujii, Y., Griffies,
S. M., Gusev, A., Heimbach, P., Howard, A., Ilicak, M., Jung, T., Karspeck,
A. R., Kelley, M., Large, W. G., Leboissetier, A., Lu, J., Madec, G.,
Marsland, S. J., Masina, S., Navarra, A., Nurser, A. J., Pirani, A., Romanou,
A., Mélia David, S., Samuels, B. L., Scheinert, M., Sidorenko, D.,
Sun, S., Treguier, A. M., Tsujino, H., Uotila, P., Valcke, S., Voldoire, A.,
Wang, Q., and Yashayaev, I.: North Atlantic simulations in Coordinated
Ocean-ice Reference Experiments phase II (CORE-II). Part II: Inter-annual to
decadal variability, Ocean Model., 97, 65–90,
https://doi.org/10.1016/j.ocemod.2015.11.007, 2016. a, b
Debreu, L., Vouland, C., and Blayo, E.: AGRIF: Adaptive grid refinement in
Fortran, Comput. Geosci., 34, 8–13,
https://doi.org/10.1016/j.cageo.2007.01.009, 2008. a
Dengler, M., Schott, F. A., Eden, C., Brandt, P., Fischer, J., and Zantopp,
R. J.: Break-up of the Atlantic deep western boundary current into eddies at
8∘ S, Nature, 432, 1018–1020, https://doi.org/10.1038/nature03134, 2004. a, b
Dickson, R. R. and Brown, J.: The production of North Atlantic Deep Water:
sources, rates, and pathways, J. Geophys. Res., 99, 12319–12341,
https://doi.org/10.1029/94jc00530, 1994. a
DiNezio, P. N., Gramer, L. J., Johns, W. E., Meinen, C. S., and Baringer,
M. O.: Observed interannual variability of the Florida current: Wind forcing
and the North Atlantic Oscillation, J. Phys. Oceanogr., 39, 721–736,
https://doi.org/10.1175/2008JPO4001.1, 2009. a
Eden, C. and Böning, C.: Sources of eddy kinetic energy in the Labrador
Sea, J. Phys. Oceanogr., 32, 3346–3363,
https://doi.org/10.1175/1520-0485(2002)032<3346:SOEKEI>2.0.CO;2, 2002. a
Eyring, V., Bony, S., Meehl, G. A., Senior, C. A., Stevens, B., Stouffer,
R. J., and Taylor, K. E.: Overview of the Coupled Model Intercomparison
Project Phase 6 (CMIP6) experimental design and organization, Geosci. Model
Dev., 9, 1937–1958, https://doi.org/10.5194/gmd-9-1937-2016, 2016. a
Fichefet, T. and Morales Maqueda, M. A.: Sensitivity of a global sea ice
model to the treatment of ice thermodynamic and dynamics, J. Geophys. Res.,
102, 12609–12646, https://doi.org/10.1029/97JC00480, 1997. a
Fischer, J., Schott, F. A., and Dengler, M.: Boundary circulation at the exit
of the Labrador Sea, J. Phys. Oceanogr., 34, 1548–1570,
https://doi.org/10.1175/1520-0485(2004)034<1548:BCATEO>2.0.CO;2, 2004. a, b, c
Fischer, J., Karstensen, J., Zantopp, R., Visbeck, M., Biastoch, A., Behrens,
E., Böning, C. W., Quadfasel, D., Jochumsen, K., Valdimarsson, H.,
Jónsson, S., Bacon, S., Holliday, N. P., Dye, S., Rhein, M., and
Mertens, C.: Intra-seasonal variability of the DWBC in the western subpolar
North Atlantic, Prog. Oceanogr., 132, 233–249,
https://doi.org/10.1016/j.pocean.2014.04.002, 2015. a
Fox-Kemper, B., Adcroft, A., Böning, C. W., Chassignet, E. P.,
Curchitser, E., Danabasoglu, G., Eden, C., England, M. H., Gerdes, R.,
Greatbatch, R. J., Griffies, S. M., Hallberg, R. W., Hanert, E., Heimbach,
P., Hewitt, H. T., Hill, C. N., Komuro, Y., Legg, S., Sommer, J. L., Masina,
S., Marsland, S. J., Penny, S. G., Qiao, F., Ringler, T. D., Treguier, A. M.,
Tsujino, H., Uotila, P., and Yeager, S. G.: Challenges and prospects in
ocean circulation models, Front. Mar. Sci., 6, 65, https://doi.org/10.3389/fmars.2019.00065, 2019. a
Frajka-Williams, E., Ansorge, I. J., Baehr, J., Bryden, H. L., Chidichimo,
M. P., Cunningham, S. A., Danabasoglu, G., Dong, S., Donohue, K. A., Elipot,
S., Heimbach, P., Holliday, N. P., Hummels, R., Jackson, L. C., Karstensen,
J., Lankhorst, M., Le Bras, I. A., Lozier, M. S., McDonagh, E. L., Meinen,
C. S., Mercier, H., Moat, B. I., Perez, R. C., Piecuch, C. G., Rhein, M.,
Srokosz, M. A., Trenberth, K. E., Bacon, S., Forget, G., Goni, G., Kieke, D.,
Koelling, J., Lamont, T., McCarthy, G. D., Mertens, C., Send, U., Smeed,
D. A., Speich, S., van den Berg, M., Volkov, D., and Wilson, C.: Atlantic
Meridional Overturning Circulation: Observed Transport and Variability,
Front. Mar. Sci., 6, 260, https://doi.org/10.3389/fmars.2019.00260, 2019. a, b
Gary, S. F., Lozier, M., Böning, C. W., and Biastoch, A.: Deciphering
the pathways for the deep limb of the Meridional Overturning Circulation,
Deep-Sea Res. Pt. II, 58, 1781–1797,
https://doi.org/10.1016/j.dsr2.2010.10.059, 2011. a
Gary, S. F., Fox, A. D., Biastoch, A., Roberts, J. M., and Cunningham, S. A.:
Larval behaviour, dispersal and population connectivity in the deep sea,
Sci. Rep., 10, 10675, https://doi.org/10.1038/s41598-020-67503-7, 2020. a
Garzoli, S. L. and Matano, R.: The South Atlantic and the Atlantic Meridional
Overturning Circulation, Deep-Sea Res. Pt. II, 58,
1837–1847, https://doi.org/10.1016/j.dsr2.2010.10.063, 2011. a
Getzlaff, K., Böning, C. W., and Dengg, J.: Lagrangian perspectives of
deep water export from the subpolar North Atlantic, Geophys. Res. Lett., 33, 21,
https://doi.org/10.1029/2006GL026470, 2006. a
Griffies, S. M., Biastoch, A., Böning, C., Bryan, F., Danabasoglu, G.,
Chassignet, E. P., England, M. H., Gerdes, R., Haak, H., Hallberg, R. W.,
Hazeleger, W., Jungclaus, J., Large, W. G., Madec, G., Pirani, A., Samuels,
B. L., Scheinert, M., Gupta, A. S., Severijns, C. a., Simmons, H. L.,
Treguier, A. M., Winton, M., Yeager, S., and Yin, J.: Coordinated Ocean-ice
Reference Experiments (COREs), Ocean Model., 26, 1–46,
https://doi.org/10.1016/j.ocemod.2008.08.007, 2009. a, b, c, d, e, f
Griffies, S. M., Danabasoglu, G., Durack, P. J., Adcroft, A. J., Balaji, V.,
Böning, C. W., Chassignet, E. P., Curchitser, E., Deshayes, J., Drange,
H., Fox-Kemper, B., Gleckler, P. J., Gregory, J. M., Haak, H., Hallberg,
R. W., Heimbach, P., Hewitt, H. T., Holland, D. M., Ilyina, T., Jungclaus,
J. H., Komuro, Y., Krasting, J. P., Large, W. G., Marsland, S. J., Masina,
S., McDougall, T. J., George Nurser, A. J., Orr, J. C., Pirani, A., Qiao,
F., Stouffer, R. J., Taylor, K. E., Treguier, A. M., Tsujino, H., Uotila, P.,
Valdivieso, M., Wang, Q., Winton, M., and Yeager, S. G.: OMIP contribution
to CMIP6: Experimental and diagnostic protocol for the physical component of
the Ocean Model Intercomparison Project, Geosci. Model Dev., 9, 3231–3296,
https://doi.org/10.5194/gmd-9-3231-2016, 2016. a, b
Hallberg, R.: Using a resolution function to regulate parameterizations of
oceanic mesoscale eddy effects, Ocean Model., 72, 92–103,
2013. a
Handmann, P., Fischer, J., Visbeck, M., Karstensen, J., Biastoch, A.,
Böning, C., and Patara, L.: The Deep Western Boundary Current in the
Labrador Sea From Observations and a High-Resolution Model, J. Geophys. Res.-Ocean., 123, 2829–2850, https://doi.org/10.1002/2017JC013702, 2018. a, b, c, d, e, f, g
Hansen, B., Húsgarð Larsen, K. M., Hátún, H., and
Østerhus, S.: A stable Faroe Bank Channel overflow 1995–2015, Ocean
Sci., 12, 1205–1220, https://doi.org/10.5194/os-12-1205-2016, 2016. a, b
Harden, B. E., Pickart, R. S., Valdimarsson, H., Våge, K., de Steur, L.,
Richards, C., Bahr, F., Torres, D., Børve, E., Jónsson, S.,
Macrander, A., Østerhus, S., Håvik, L., and Hattermann, T.: Upstream
sources of the Denmark Strait Overflow: Observations from a high-resolution
mooring array, Deep-Sea Res. Pt. I, 112, 94–112,
https://doi.org/10.1016/j.dsr.2016.02.007, 2016. a, b
Herrford, J., Brandt, P., Kanzow, T., Hummels, R., Araujo, M., and Durgadoo,
J. V.: Seasonal variability of the Atlantic Meridional Overturning
Circulation at 11∘ S inferred from bottom pressure measurements,
Ocean Sci., 17, 265–284, https://doi.org/10.5194/os-17-265-2021, 2021. a, b, c
Hewitt, H. T., Roberts, M., Mathiot, P., Biastoch, A., Blockley, E.,
Chassignet, E. P., Fox-Kemper, B., Hyder, P., Marshall, D. P., Popova, E.,
Treguier, A. M., Zanna, L., Yool, A., Yu, Y., Beadling, R., Bell, M.,
Kuhlbrodt, T., Arsouze, T., Bellucci, A., Castruccio, F., Gan, B.,
Putrasahan, D., Roberts, C. D., Van Roekel, L., and Zhang, Q.: Resolving
and Parameterising the Ocean Mesoscale in Earth System Models, Curr. Clim.
Chang. Report., 6, 137–152, https://doi.org/10.1007/s40641-020-00164-w, 2020. a, b
Hirschi, J. J., Frajka-Williams, E., Blaker, A. T., Sinha, B., Coward, A.,
Hyder, P., Biastoch, A., Böning, C., Barnier, B., Penduff, T., Garcia,
I., Fransner, F., and Madec, G.: Loop current variability as trigger of
coherent gulf stream transport anomalies, J. Phys. Oceanogr., 49,
2115–2132, https://doi.org/10.1175/JPO-D-18-0236.1, 2019. a, b
Hirschi, J. J., Barnier, B., Böning, C., Biastoch, A., Blaker, A. T.,
Coward, A., Danilov, S., Drijfhout, S., Getzlaff, K., Griffies, S. M.,
Hasumi, H., Hewitt, H., Iovino, D., Kawasaki, T., Kiss, A. E., Koldunov, N.,
Marzocchi, A., Mecking, J. V., Moat, B., Molines, J. M., Myers, P. G.,
Penduff, T., Roberts, M., Treguier, A. M., Sein, D. V., Sidorenko, D., Small,
J., Spence, P., Thompson, L. A., Weijer, W., and Xu, X.: The Atlantic
Meridional Overturning Circulation in High-Resolution Models, J. Geophys.
Res.-Ocean., 125, e2019JC015522, https://doi.org/10.1029/2019JC015522, 2020. a, b, c, d
Hollingsworth, A., Kållberg, P., Renner, V., and Burridge, D. M.: An
internal symmetric computational instability, Q. J. Roy.
Meteor. Soc., 109, 417–428, 1983. a
Hummels, R., Brandt, P., Dengler, M., Fischer, J., Araujo, M., Veleda, D., and
Durgadoo, J. V.: Interannual to decadal changes in the western boundary
circulation in the Atlantic at 11∘ S, Geophys. Res. Lett., 42, 7615–7622,
https://doi.org/10.1002/2015GL065254, 2015. a, b, c, d
Jackson, L. C., Dubois, C., Forget, G., Haines, K., Harrison, M., Iovino, D.,
Köhl, A., Mignac, D., Masina, S., Peterson, K. A., Piecuch, C. G.,
Roberts, C. D., Robson, J., Storto, A., Toyoda, T., Valdivieso, M., Wilson,
C., Wang, Y., and Zuo, H.: The Mean State and Variability of the North
Atlantic Circulation: A Perspective From Ocean Reanalyses, J.
Geophys. Res.-Ocean., 124, 9141–9170,
https://doi.org/10.1029/2019JC015210, 2019. a
Jochumsen, K., Moritz, M., Nunes, N., Quadfasel, D., Larsen, K. M. H., Hansen,
B., Valdimarsson, H., and Jonsson, S.: Revised transport estimates of the
Denmark Strait overflow, J. Geophys. Res.-Ocean., 122, 3434–3450,
https://doi.org/10.1002/2017JC012803, 2017. a
Karspeck, A. R., Stammer, D., Köhl, A., Danabasoglu, G., Balmaseda, M.,
Smith, D. M., Fujii, Y., Zhang, S., Giese, B., Tsujino, H., and Rosati, A.:
Comparison of the Atlantic meridional overturning circulation between 1960
and 2007 in six ocean reanalysis products, Clim. Dynam., 49, 957–982,
https://doi.org/10.1007/s00382-015-2787-7, 2015. a
Käse, R. H., Girton, J. B., and Sanford, T. B.: Structure and
variability of the Denmark Strait Overflow: Model and observations, J.
Geophys. Res.-Ocean., 108, 3181, https://doi.org/10.1029/2002jc001548, 2003. a
Kersalé, M., Meinen, C. S., Perez, R. C., Piola, A. R., Speich, S., Campos, E. J. D., Garzoli, S. L., Ansorge, I., Volkov, D. L., Le Hénaff, M., Dong, S., Lamont, T., Sato, O. T., and van den Berg, M.: Multi-year estimates of daily heat transport by the Atlantic meridional overturning circulation at 34.5∘ S, J. Geophys. Res.-Ocean., 126, 5, https://doi.org/10.1029/2020JC016947, 2021. a
Kirchner, K., Rhein, M., Hüttl-Kabus, S., and Böning, C. W.: On
the spreading of South Atlantic Water into the Northern Hemisphere, J.
Geophys. Res.-Ocean., 114, C05019, https://doi.org/10.1029/2008JC005165, 2009. a
Koul, V., Tesdal, J.-E., Bersch, M., Hátún, H., Brune, S., Borchert, L.,
Haak, H., Schrum, C., and Baehr, J.: Unraveling the choice of the north
Atlantic subpolar gyre index, Sci. Rep., 10, 1005,
https://doi.org/10.1038/s41598-020-57790-5, 2020. a
Latif, M., Böning, C., Willebrand, J., Biastoch, A., Dengg, J.,
Keenlyside, N., Schwecjendiek, U., and Madec, G.: Is the thermohaline
circulation changing?, J. Clim., 19, 4631–4637,
https://doi.org/10.1175/JCLI3876.1, 2006. a
Lavender, K. L., Davis, R. E., and Owens, W. B.: Mid-depth recirculation
observed in the interior Labrador and Irminger seas by direct velocity
measurements, Nature, 407, 66–69, https://doi.org/10.1038/35024048, 2000. a
Le Bras, I. A., Yashayaev, I., and Toole, J. M.: Tracking Labrador Sea Water
property signals along the Deep Western Boundary Current, J. Geophys. Res.-Ocean., 122, 5348–5366, https://doi.org/10.1002/2017JC012921, 2017. a
Lee, T. N. and Williams, E.: Wind-Forced Transport Fluctuations of the Florida
Current, J. Phys. Oceanogr., 18, 937–946,
https://doi.org/10.1175/1520-0485(1988)018<0937:wftfot>2.0.co;2, 1988. a
Legg, S., Hallberg, R. W., and Girton, J. B.: Comparison of entrainment in
overflows simulated by z-coordinate, isopycnal and non-hydrostatic models,
Ocean Model., 11, 69–97, https://doi.org/10.1016/j.ocemod.2004.11.006, 2006. a, b, c
Lemarié, F.: NEMO/AGRIF Nesting tools, User’s Guide (30 January 2006), available at: http://forge.ipsl.jussieu.fr/nemo/attachment/wiki/Users/SetupNewConfiguration/AGRIF-nesting-tool/doc_nesting_tools.pdfforge.ipsl.jussieu.fr/nemo/attachment/ (last access: 25 August 2021), 2006. a
Levitus, S., Boyer, T. P., Conkright, M. E., Brien, T. O., Antonov, J.,
Stephens, C., Stathoplos, L., Johnson, D., and Gelfeld, R.: World Ocean Database 1998, Vol. 1, Introduction, NOAA Atlas NESDIS 18, U.S. Government Printing Office, Washington, D.C., 1998. a
Locarnini, R. A., Mishonov, A. V., Antonov, J. I., Boyer, T. P., Garcia, H. E.,
Baranova, O. K., Zweng, M. M., Paver, C. R., Reagan, J. R., Johnson, D. R.,
Hamilton, M., Seidov, D., and Levitus, S.: World ocean atlas 2013,
Vol. 1, NOAA Atlas, Temperature, 73, https://doi.org/10.7289/V55X26VD, 2013. a
Lozier, M. S.: Deconstructing the conveyor belt, Science, 328,
1507–1511, https://doi.org/10.1126/science.1189250, 2010. a
Lozier, M. S., Gary, S. F., and Bower, A. S.: Simulated pathways of the
overflow waters in the North Atlantic: Subpolar to subtropical export, Deep-Sea
Res. Pt. II, 85, 147–153,
https://doi.org/10.1016/j.dsr2.2012.07.037, 2013. a
Lozier, M. S., Bacon, S., Bower, A. S., Cunningham, S. A., De Jong, M. F.,
De Steur, L., De Young, B., Fischer, J., Gary, S. F., Greenan, B. J.,
Heimbach, P., Holliday, N. P., Houpert, L., Inall, M. E., Johns, W. E.,
Johnson, H. L., Karstensen, J., Li, F., Lin, X., Mackay, N., Marshall, D. P.,
Mercier, H., Myers, P. G., Pickart, R. S., Pillar, H. R., Straneo, F.,
Thierry, V., Weller, R. A., Williams, R. G., Wilson, C., Yang, J., Zhao, J.,
and Zika, J. D.: Overturning in the Subpolar north Atlantic program: A new
international ocean observing system, Bull. Am. Meteorol. Soc., 98,
737–752, https://doi.org/10.1175/BAMS-D-16-0057.1, 2017. a
Lozier, M. S., Li, F., Bacon, S., Bahr, F., Bower, A. S., Cunningham, S. A.,
De Jong, M. F., De Steur, L., DeYoung, B., Fischer, J., Gary, S. F.,
Greenan, B. J., Holliday, N. P., Houk, A., Houpert, L., Inall, M. E., Johns,
W. E., Johnson, H. L., Johnson, C., Karstensen, J., Koman, G., Le Bras,
I. A., Lin, X., Mackay, N., Marshall, D. P., Mercier, H., Oltmanns, M.,
Pickart, R. S., Ramsey, A. L., Rayner, D., Straneo, F., Thierry, V., Torres,
D. J., Williams, R. G., Wilson, C., Yang, J., Yashayaev, I., and Zhao, J.: A
sea change in our view of overturning in the subpolar North Atlantic,
Science, 363, 516–521, https://doi.org/10.1126/science.aau6592, 2019. a
Madec, G.: NEMO ocean engine, Note du Pôle modélisation, Inst.
Pierre-Simon Laplace, p. 406, 2016. a
Maltrud, M. E., Smith, R. D., Semtner, A. J., and Malone, R. C.: Global
eddy-resolving ocean simulations driven by 1985–1995 atmospheric winds, J.
Geophys. Res.-Ocean., 103, 30825–30853, https://doi.org/10.1029/1998jc900013,
1998. a
Martin, T.: Runoff remapping for ocean model forcing, GEOMAR [data set], https://doi.org/10.3289/SW_2_2021, last access: 27 August 2021. a
Matthes, K., Biastoch, A., Wahl, S., Harlaß, J., Martin, T., Brücher,
T., Drews, A., Ehlert, D., Getzlaff, K., Krüger, F., Rath, W.,
Scheinert, M., U. Schwarzkopf, F., Bayr, T., Schmidt, H., and Park, W.:
The Flexible Ocean and Climate Infrastructure version 1 (FOCI1): Mean state
and variability, Geosci. Model Dev., 13, 2533–2568,
https://doi.org/10.5194/gmd-13-2533-2020, 2020. a
McCarthy, G., Frajka-Williams, E., Johns, W. E., Baringer, M. O., Meinen,
C. S., Bryden, H. L., Rayner, D., Duchez, A., Roberts, C., and Cunningham,
S. A.: Observed interannual variability of the Atlantic meridional
overturning circulation at 26.5∘ N, Geophys. Res. Lett., 39, L19609,
https://doi.org/10.1029/2012GL052933, 2012. a
Meinen, C. S., Baringer, M. O., and Garcia, R. F.: Florida Current transport
variability: An analysis of annual and longer-period signals, Deep-Sea
Res. Pt. I, 57, 835–846, 2010. a
Meinen, C. S., Speich, S., Piola, A. R., Ansorge, I., Campos, E.,
Kersalé, M., Terre, T., Chidichimo, M. P., Lamont, T., Sato, O. T.,
Perez, R. C., Valla, D., van den Berg, M., Le Hénaff, M., Dong, S.,
and Garzoli, S. L.: Meridional Overturning Circulation Transport Variability
at 34.5∘ S During 2009–2017: Baroclinic and Barotropic Flows and the
Dueling Influence of the Boundaries, Geophys. Res. Lett., 45, 4180–4188,
https://doi.org/10.1029/2018GL077408, 2018. a, b, c
Mertens, C., Rhein, M., Walter, M., Böning, C. W., Behrens, E., Kieke,
D., Steinfeldt, R., and Stöber, U.: Circulation and transports in the
Newfoundland Basin, western subpolar North Atlantic, J. Geophys. Res.-Ocean., 119, 7772–7793, https://doi.org/10.1002/2014JC010019, 2014. a
Moat, B. I., Smeed, D. A., Frajka-Williams, E., Desbruyères, D. G.,
Beaulieu, C., Johns, W. E., Rayner, D., Sanchez-Franks, A., Baringer, M. O.,
Volkov, D., Jackson, L. C., and Bryden, H. L.: Pending recovery in the
strength of the meridional overturning circulation at 26∘ N, Ocean Sci.,
16, 863–874, https://doi.org/10.5194/os-16-863-2020, 2020. a, b
Msadek, R., Johns, W. E., Yeager, S. G., Danabasoglu, G., Delworth, T. L., and
Rosati, A.: The Atlantic meridional heat transport at 26.5∘ N and its
relationship with the MOC in the RAPID array and the GFDL and NCAR coupled
models, J. Clim., 26, 4335–4356, https://doi.org/10.1175/JCLI-D-12-00081.1, 2013. a
NEMO System Team: NEMO version 3.6 [data set], available at: https://forge.ipsl.jussieu.fr/nemo/svn/NEMO/releases/release-3.6, last access: 27 August 2021. a
Østerhus, S., Woodgate, R., Valdimarsson, H., Turrell, B., De Steur, L.,
Quadfasel, D., Olsen, S. M., Moritz, M., Lee, C. M., Larsen, K. M. H.,
Jónsson, S., Johnson, C., Jochumsen, K., Hansen, B., Curry, B.,
Cunningham, S., and Berx, B.: Arctic Mediterranean exchanges: A consistent
volume budget and trends in transports from two decades of observations,
Ocean Sci., 15, 379–399, https://doi.org/10.5194/os-15-379-2019, 2019. a
Peña-Molino, B., Joyce, T. M., and Toole, J. M.: Variability in the Deep
Western boundary current: Local versus remote forcing, J. Geophys. Res.-Ocean., 117, C12022, https://doi.org/10.1029/2012JC008369, 2012. a
Penduff, T., Le Sommer, J., Barnier, B., Treguier, A. M., Molines, J. M., and
Madec, G.: Influence of numerical schemes on current-topography interactions
in
Rabe, B., Karcher, M., Kauker, F., Schauer, U., Toole, J. M., Krishfield,
R. A., Pisarev, S., Kikuchi, T., and Su, J.: Arctic Ocean basin liquid
freshwater storage trend 1992–2012, Geophys. Res. Lett., 41, 961–968,
https://doi.org/10.1002/2013GL058121, 2014. a
Rahmstorf, S. and Willebrand, J.: The role of temperature feedback in
stabilizing the thermohaline circulation, J. Phys. Oceanogr.,
25, 787–805, 1995. a
Rayner, N. A., Parker, D. E., Horton, E. B., Folland, C. K., Alexander, L. V.,
Rowell, D. P., Kent, E. C., and Kaplan, A.: Global analyses of sea surface
temperature, sea ice, and night marine air temperature since the late
nineteenth century, J. Geophys. Res.-Atmos., 108, 4407,
https://doi.org/10.1029/2002jd002670, 2003. a
Reichstein, M., Camps-Valls, G., Stevens, B., Jung, M., Denzler, J.,
Carvalhais, N., and Prabhat: Deep learning and process understanding for
data-driven Earth system science, Nature, 566, 195–204,
https://doi.org/10.1038/s41586-019-0912-1, 2019. a
Rossby, T., Flagg, C., Chafik, L., Harden, B., and Søiland, H.: A Direct
Estimate of Volume, Heat, and Freshwater Exchange Across the
Greenland‐Iceland‐Faroe‐Scotland Ridge, J. Geophys.
Res.-Ocean., 123, 7139–7153, 2018. a
Roullet, G. and Madec, G.: Salt conservation, free surface and varying levels:
a new formulation for ocean general circulation models, J. Geophys. Res.,
105, 23927–23942, 2000. a
Rühs, S., Getzlaff, K., Durgadoo, J. V., Biastoch, A., and Böning,
C. W.: On the suitability of North Brazil Current transport estimates for
monitoring basin-scale AMOC changes, Geophys. Res. Lett., 42,
8072–8080, https://doi.org/10.1002/2015GL065695, 2015. a, b, c
Rühs, S., Oliver, E. C. J., Biastoch, A., Böning, C. W., Dowd, M.,
Getzlaff, K., Martin, T., and Myers, P. G.: Changing spatial patterns of
deep convection in the subpolar North Atlantic, J. Geophys. Res.-Ocean.,
126, e2021JC017245, https://doi.org/10.1029/2021jc017245, 2021. a, b
Schott, F. and Brandt, P.: Circulation and deep water export of the subpolar
North Atlantic during the 1990's, in: Ocean Circulation: Mechanisms and Impacts – Past and Future Changes of Meridional Overturning, edited by: Schmittner, A., Chiang, J. C. H., and Hemming, S. R., Vol.
173 of Geophysical Monograph Series,
Washington, DC, 91–118, 2007. a
Schott, F. A., Mccreary Jr., J. P., and Johnson, G. C.: Shallow Overturning
Circulations of the Tropical-Subtropical Oceans, American
Geophysical Union (AGU), in: Earth's Climate: The Ocean-Atmosphere Interaction, Vol. 147,
edited by: Wang, C., Xie, S. P., and Carton, J. A., Geophysical Monograph Series, 261–304, https://doi.org/10.1029/147GM15, 2004. a
Schubert, R., Biastoch, A., Cronin, M. F., and Greatbatch, R. J.:
Instability-driven benthic storms below the separated gulf stream and the
North Atlantic current in a high-resolution ocean model, J. Phys. Oceanogr.,
48, 2283–2303, https://doi.org/10.1175/JPO-D-17-0261.1, 2018. a
Schulzki, T., Getzlaff, K., and Biastoch, A.: On the Variability of the DWBC
Transport Between 26.5∘ N and 16∘ N in an Eddy‐Rich Ocean
Model, J. Geophys. Res.-Ocean., 126, e2021JC017372,
https://doi.org/10.1029/2021jc017372, 2021. a, b
Schwarzkopf, F. U.: Ventilation pathways in the tropical Atlantic and Pacific
Oceans with a focus on the Oxygen Minimum Zones: development and application
of a nested high-resolution global model system, Phd/doctoral thesis,
Christian-Albrechts-Universität Kiel, available at:
http://oceanrep.geomar.de/34702/ (last access: 25 August 2021), 2016. a
Schwarzkopf, F. U., Biastoch, A., Böning, C. W., Chanut, J., Durgadoo,
J. V., Getzlaff, K., Harlaß, J., Rieck, J. K., Roth, C., Scheinert,
M. M., and Schubert, R.: The INALT family – A set of high-resolution nests
for the Agulhas Current system within global NEMO ocean/sea-ice
configurations, Geosci. Model Dev., 12, 3329–3355,
https://doi.org/10.5194/gmd-12-3329-2019, 2019. a, b, c, d
Send, U., Lankhorst, M., and Kanzow, T.: Observation of decadal change in the
Atlantic meridional overturning circulation using 10 years of continuous
transport data, Geophys. Res. Lett., 38, L24606, https://doi.org/10.1029/2011GL049801,
2011. a
Sinha, B., Smeed, D. A., McCarthy, G., Moat, B. I., Josey, S. A., Hirschi,
J. J., Frajka-Williams, E., Blaker, A. T., Rayner, D., and Madec, G.: The
accuracy of estimates of the overturning circulation from basin-wide mooring
arrays, Prog. Oceanogr., 160, 101–123,
https://doi.org/10.1016/j.pocean.2017.12.001, 2018. a
Smith, R. D., Maltrud, M. E., Bryan, F. O., and Hecht, M. W.: Numerical
simulation of the North Atlantic Ocean at
Solodoch, A., McWilliams, J. C., Stewart, A. L., Gula, J., and Renault, L.:
Why does the deep western boundary current ‘‘leak” around flemish
cap?, J. Phys. Oceanogr., 50, 1989–2016, https://doi.org/10.1175/JPO-D-19-0247.1,
2020. a
Sonnewald, M., Wunsch, C., and Heimbach, P.: Unsupervised Learning Reveals
Geography of Global Ocean Dynamical Regions, Earth Sp. Sci., 6, 784–794,
https://doi.org/10.1029/2018EA000519, 2019. a
Srokosz, M., Danabasoglu, G., and Patterson, M.: Atlantic Meridional
Overturning Circulation: Reviews of Observational and Modeling Advances –
an Introduction, J. Geophys. Res.-Ocean., 126, 1, https://doi.org/10.1029/2020jc016745, 2020. a
Steele, M., Morley, R., and Ermold, W.: PHC: A global ocean hydrography with a
high quality Arctic Ocean, J. Clim., 14, 2079–2087, 2001. a
Steinle, L., Graves, C. A., Treude, T., Ferré, B., Biastoch, A.,
Bussmann, I., Berndt, C., Krastel, S., James, R. H., Behrens, E.,
Böning, C. W., Greinert, J., Sapart, C. J., Scheinert, M., Sommer, S.,
Lehmann, M. F., and Niemann, H.: Water column methanotrophy controlled by a
rapid oceanographic switch, Nat. Geosci., 8, 378–382,
https://doi.org/10.1038/ngeo2420, 2015. a
Stommel, H.: The abyssal circulation, Deep-Sea Res., 5, 80–82,
https://doi.org/10.1016/S0146-6291(58)80014-4, 1958. a
Thoma, M., Gerdes, R., Greatbatch, R. J., and Ding, H.: Partially coupled
spin-up of the MPI-ESM: implementation and first results, Geosci. Model
Dev., 8, 51–68, https://doi.org/10.5194/gmd-8-51-2015, 2015. a
Toole, J. M., Andres, M., Le Bras, I. A., Joyce, T. M., and McCartney, M. S.:
Moored observations of the Deep Western Boundary Current in the NW Atlantic:
2004–2014, J. Geophys. Res.-Ocean., 122, 7488–7505,
https://doi.org/10.1002/2017JC012984, 2017. a
Treguier, A. M., Theetten, S., Chassignet, E. P., Penduff, T., Smith, R.,
Talley, L., Beismann, J. O., and Böning, C.: The North Atlantic
subpolar gyre in four high-resolution models, J. Phys. Oceanogr., 35,
757–774, https://doi.org/10.1175/JPO2720.1, 2005. a
Tsujino, H., Urakawa, S., Nakano, H., Small, R. J., Kim, W. M., Yeager, S. G.,
Danabasoglu, G., Suzuki, T., Bamber, J. L., Bentsen, M., Böning, C. W.,
Bozec, A., Chassignet, E. P., Curchitser, E., Boeira Dias, F., Durack,
P. J., Griffies, S. M., Harada, Y., Ilicak, M., Josey, S. A., Kobayashi, C.,
Kobayashi, S., Komuro, Y., Large, W. G., Le Sommer, J., Marsland, S. J.,
Masina, S., Scheinert, M., Tomita, H., Valdivieso, M., and Yamazaki, D.:
JRA-55 based surface dataset for driving ocean–sea-ice models (JRA55-do),
Ocean Model., 130, 79–139, https://doi.org/10.1016/j.ocemod.2018.07.002, 2018. a, b
Tsujino, H., Urakawa, L. S., Griffies, S. M., Danabasoglu, G., Adcroft, A. J., Amaral, A. E., Arsouze, T., Bentsen, M., Bernardello, R., Böning, C. W., Bozec, A., Chassignet, E. P., Danilov, S., Dussin, R., Exarchou, E., Fogli, P. G., Fox-Kemper, B., Guo, C., Ilicak, M., Iovino, D., Kim, W. M., Koldunov, N., Lapin, V., Li, Y., Lin, P., Lindsay, K., Liu, H., Long, M. C., Komuro, Y., Marsland, S. J., Masina, S., Nummelin, A., Rieck, J. K., Ruprich-Robert, Y., Scheinert, M., Sicardi, V., Sidorenko, D., Suzuki, T., Tatebe, H., Wang, Q., Yeager, S. G., and Yu, Z.: Evaluation of global ocean–sea-ice model simulations based on the experimental protocols of the Ocean Model Intercomparison Project phase 2 (OMIP-2), Geosci. Model Dev., 13, 3643–3708, https://doi.org/10.5194/gmd-13-3643-2020, 2020. a, b, c, d
Van Sebille, E., Johns, W. E., and Beal, L. M.: Does the vorticity flux from
Agulhas rings control the zonal pathway of NADW across the South Atlantic?,
J. Geophys. Res.-Ocean., 117, C05037, https://doi.org/10.1029/2011JC007684, 2012. a
Weijer, W., Cheng, W., Garuba, O. A., Hu, A., and Nadiga, B. T.: CMIP6 Models
Predict Significant 21st Century Decline of the Atlantic Meridional
Overturning Circulation, Geophys. Res. Lett., 47, e2019GL086075,
https://doi.org/10.1029/2019GL086075, 2020. a
Wunsch, C. and Heimbach, P.: Two decades of the atlantic meridional
overturning circulation: Anatomy, variations, extremes, prediction, and
overcoming its limitations, J. Clim., 26, 7167–7186,
https://doi.org/10.1175/JCLI-D-12-00478.1, 2013. a
Xu, X., Schmitz, W. J., Hurlburt, H. E., Hogan, P. J., and Chassignet, E. P.:
Transport of Nordic Seas overflow water into and within the Irminger Sea: An
eddy-resolving simulation and observations, J. Geophys. Res.-Ocean., 115,
C12048, https://doi.org/10.1029/2010JC006351, 2010. a
Yashayaev, I.: Hydrographic changes in the Labrador Sea, 1960–2005, Prog.
Oceanogr., 73, 242–276, https://doi.org/10.1016/j.pocean.2007.04.015, 2007. a
Yeager, S. and Danabasoglu, G.: The origins of late-twentieth-century
variations in the large-scale North Atlantic circulation, J. Clim., 27,
3222–3247, https://doi.org/10.1175/JCLI-D-13-00125.1, 2014.
a
Zalesak, S. T.: Fully multidimensional flux-corrected transport algorithms for
fluids, J. Comput. Phys., 31, 335–362, 1979. a
Zantopp, R., Fischer, J., Visbeck, M., and Karstensen, J.: From interannual to
decadal: 17 years of boundary current transports at the exit of the Labrador
Sea, J. Geophys. Res.-Ocean., 122, 1724–1748, https://doi.org/10.1002/2016JC012271,
2017. a, b, c, d
Zou, S., Lozier, S., Zenk, W., Bower, A., and Johns, W.: Observed and modeled
pathways of the Iceland Scotland Overflow Water in the eastern North
Atlantic, Prog. Oceanogr., 159, 211–222,
https://doi.org/10.1016/j.pocean.2017.10.003, 2017. a
Zou, S., Lozier, M. S., and Buckley, M.: How Is Meridional Coherence
Maintained in the Lower Limb of the Atlantic Meridional Overturning
Circulation?, Geophys. Res. Lett., 46, 244–252, https://doi.org/10.1029/2018GL080958,
2019. a
Zweng, M. M., Reagan, J. R., Antonov, J. I., Locarnini, R. A., Mishonov, A. V.,
Boyer, T. P., Garcia, H. E., Baranova, O. K., Johnson, D. R., Seidov 1948-,
D., Biddle, M. M., and Levitus, S.: World ocean atlas 2013, Vol. 2,
Salinity, NOAA Atlas NESDIS series, no. 74, https://doi.org/10.7289/V5251G4D, 2013. a
Short summary
The Atlantic Meridional Overturning Circulation (AMOC) quantifies the impact of the ocean on climate and climate change. Here we show that a high-resolution ocean model is able to realistically simulate ocean currents. While the mean representation of the AMOC depends on choices made for the model and on the atmospheric forcing, the temporal variability is quite robust. Comparing the ocean model with ocean observations, we able to identify that the AMOC has declined over the past two decades.
The Atlantic Meridional Overturning Circulation (AMOC) quantifies the impact of the ocean on...
