Articles | Volume 20, issue 1
https://doi.org/10.5194/os-20-85-2024
© Author(s) 2024. 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-20-85-2024
© Author(s) 2024. This work is distributed under
the Creative Commons Attribution 4.0 License.
the Creative Commons Attribution 4.0 License.
Research article
| 
22 Jan 2024
Research article |
| 22 Jan 2024
| 22 Jan 2024
Altered Weddell Sea warm- and dense-water pathways in response to 21st-century climate change
Alfred Wegener Institute, Helmholtz-Zentrum für Polar- und Meeresforschung, Bremerhaven, Germany
Department of Atmospheric and Oceanic Sciences and Institute of Arctic and Alpine Research, University of Colorado Boulder, Boulder, CO, USA
Ralph Timmermann
CORRESPONDING AUTHOR
Alfred Wegener Institute, Helmholtz-Zentrum für Polar- und Meeresforschung, Bremerhaven, Germany
Mathias van Caspel
Alfred Wegener Institute, Helmholtz-Zentrum für Polar- und Meeresforschung, Bremerhaven, Germany
Claudia Wekerle
Alfred Wegener Institute, Helmholtz-Zentrum für Polar- und Meeresforschung, Bremerhaven, Germany
Related authors
Vanessa Teske, Ralph Timmermann, Cara Nissen, Rolf Zentek, Tido Semmler, and Günther Heinemann
EGUsphere, https://doi.org/10.5194/egusphere-2024-2873, https://doi.org/10.5194/egusphere-2024-2873, 2024
Short summary
Short summary
We investigate the structural changes the Antarctic Slope Front in the southern Weddell Sea experiences in a warming climate by conducting two ocean simulations driven by atmospheric data of different horizontal resolution. Cross-slope currents associated with a regime shift from a cold to a warm Filchner Trough on the continental shelf temporarily disturb the structure of the slope front and reduce its depth, but the primary reason for a regime shift is the cross-slope density gradient.
Cara Nissen, Nicole S. Lovenduski, Mathew Maltrud, Alison R. Gray, Yohei Takano, Kristen Falcinelli, Jade Sauvé, and Katherine Smith
Geosci. Model Dev., 17, 6415–6435, https://doi.org/10.5194/gmd-17-6415-2024, https://doi.org/10.5194/gmd-17-6415-2024, 2024
Short summary
Short summary
Autonomous profiling floats have provided unprecedented observational coverage of the global ocean, but uncertainties remain about whether their sampling frequency and density capture the true spatiotemporal variability of physical, biogeochemical, and biological properties. Here, we present the novel synthetic biogeochemical float capabilities of the Energy Exascale Earth System Model version 2 and demonstrate their utility as a test bed to address these uncertainties.
Christoph Heinze, Thorsten Blenckner, Peter Brown, Friederike Fröb, Anne Morée, Adrian L. New, Cara Nissen, Stefanie Rynders, Isabel Seguro, Yevgeny Aksenov, Yuri Artioli, Timothée Bourgeois, Friedrich Burger, Jonathan Buzan, B. B. Cael, Veli Çağlar Yumruktepe, Melissa Chierici, Christopher Danek, Ulf Dieckmann, Agneta Fransson, Thomas Frölicher, Giovanni Galli, Marion Gehlen, Aridane G. González, Melchor Gonzalez-Davila, Nicolas Gruber, Örjan Gustafsson, Judith Hauck, Mikko Heino, Stephanie Henson, Jenny Hieronymus, I. Emma Huertas, Fatma Jebri, Aurich Jeltsch-Thömmes, Fortunat Joos, Jaideep Joshi, Stephen Kelly, Nandini Menon, Precious Mongwe, Laurent Oziel, Sólveig Ólafsdottir, Julien Palmieri, Fiz F. Pérez, Rajamohanan Pillai Ranith, Juliano Ramanantsoa, Tilla Roy, Dagmara Rusiecka, J. Magdalena Santana Casiano, Yeray Santana-Falcón, Jörg Schwinger, Roland Séférian, Miriam Seifert, Anna Shchiptsova, Bablu Sinha, Christopher Somes, Reiner Steinfeldt, Dandan Tao, Jerry Tjiputra, Adam Ulfsbo, Christoph Völker, Tsuyoshi Wakamatsu, and Ying Ye
Biogeosciences Discuss., https://doi.org/10.5194/bg-2023-182, https://doi.org/10.5194/bg-2023-182, 2023
Preprint under review for BG
Short summary
Short summary
For assessing the consequences of human-induced climate change for the marine realm, it is necessary to not only look at gradual changes but also at abrupt changes of environmental conditions. We summarise abrupt changes in ocean warming, acidification, and oxygen concentration as the key environmental factors for ecosystems. Taking these abrupt changes into account requires greenhouse gas emissions to be reduced to a larger extent than previously thought to limit respective damage.
Cara Nissen and Meike Vogt
Biogeosciences, 18, 251–283, https://doi.org/10.5194/bg-18-251-2021, https://doi.org/10.5194/bg-18-251-2021, 2021
Short summary
Short summary
Using a regional Southern Ocean ecosystem model, we find that the relative importance of Phaeocystis and diatoms at high latitudes is controlled by iron and temperature variability, with light levels controlling the seasonal succession in coastal areas. Yet, biomass losses via aggregation and grazing matter as well. We show that the seasonal succession of Phaeocystis and diatoms impacts the seasonality of carbon export fluxes with ramifications for nutrient cycling and food web dynamics.
Cara Nissen, Meike Vogt, Matthias Münnich, Nicolas Gruber, and F. Alexander Haumann
Biogeosciences, 15, 6997–7024, https://doi.org/10.5194/bg-15-6997-2018, https://doi.org/10.5194/bg-15-6997-2018, 2018
Short summary
Short summary
Using a regional ocean model, we find that coccolithophore biomass in the Southern Ocean is highest in the subantarctic in late summer when diatom growth becomes limited by silicate. We show that zooplankton grazing is crucial to explain phytoplankton biomass distributions in this area and conclude that assessments of future distributions should not only consider physical and chemical factors (temperature, light, nutrients, pH), but also interactions with other phytoplankton or zooplankton.
Vanessa Teske, Ralph Timmermann, Cara Nissen, Rolf Zentek, Tido Semmler, and Günther Heinemann
EGUsphere, https://doi.org/10.5194/egusphere-2024-2873, https://doi.org/10.5194/egusphere-2024-2873, 2024
Short summary
Short summary
We investigate the structural changes the Antarctic Slope Front in the southern Weddell Sea experiences in a warming climate by conducting two ocean simulations driven by atmospheric data of different horizontal resolution. Cross-slope currents associated with a regime shift from a cold to a warm Filchner Trough on the continental shelf temporarily disturb the structure of the slope front and reduce its depth, but the primary reason for a regime shift is the cross-slope density gradient.
Jan De Rydt, Nicolas C. Jourdain, Yoshihiro Nakayama, Mathias van Caspel, Ralph Timmermann, Pierre Mathiot, Xylar S. Asay-Davis, Hélène Seroussi, Pierre Dutrieux, Ben Galton-Fenzi, David Holland, and Ronja Reese
Geosci. Model Dev., 17, 7105–7139, https://doi.org/10.5194/gmd-17-7105-2024, https://doi.org/10.5194/gmd-17-7105-2024, 2024
Short summary
Short summary
Global climate models do not reliably simulate sea-level change due to ice-sheet–ocean interactions. We propose a community modelling effort to conduct a series of well-defined experiments to compare models with observations and study how models respond to a range of perturbations in climate and ice-sheet geometry. The second Marine Ice Sheet–Ocean Model Intercomparison Project will continue to lay the groundwork for including ice-sheet–ocean interactions in global-scale IPCC-class models.
Cara Nissen, Nicole S. Lovenduski, Mathew Maltrud, Alison R. Gray, Yohei Takano, Kristen Falcinelli, Jade Sauvé, and Katherine Smith
Geosci. Model Dev., 17, 6415–6435, https://doi.org/10.5194/gmd-17-6415-2024, https://doi.org/10.5194/gmd-17-6415-2024, 2024
Short summary
Short summary
Autonomous profiling floats have provided unprecedented observational coverage of the global ocean, but uncertainties remain about whether their sampling frequency and density capture the true spatiotemporal variability of physical, biogeochemical, and biological properties. Here, we present the novel synthetic biogeochemical float capabilities of the Energy Exascale Earth System Model version 2 and demonstrate their utility as a test bed to address these uncertainties.
Torsten Kanzow, Angelika Humbert, Thomas Mölg, Mirko Scheinert, Matthias Braun, Hans Burchard, Francesca Doglioni, Philipp Hochreuther, Martin Horwath, Oliver Huhn, Jürgen Kusche, Erik Loebel, Katrina Lutz, Ben Marzeion, Rebecca McPherson, Mahdi Mohammadi-Aragh, Marco Möller, Carolyne Pickler, Markus Reinert, Monika Rhein, Martin Rückamp, Janin Schaffer, Muhammad Shafeeque, Sophie Stolzenberger, Ralph Timmermann, Jenny Turton, Claudia Wekerle, and Ole Zeising
EGUsphere, https://doi.org/10.5194/egusphere-2024-757, https://doi.org/10.5194/egusphere-2024-757, 2024
Short summary
Short summary
The Greenland Ice Sheet represents the second-largest contributor to global sea-level rise. We quantify atmosphere, ice and ocean-based processes related to the mass balance of glaciers in Northeast Greenland, focusing on Greenland’s largest floating ice tongue, the 79N Glacier. We find that together, the different in situ and remote sensing observations and model simulations to reveal a consistent picture of a coupled atmosphere-ice sheet-ocean system, that has entered a phase of major change.
Ole Richter, Ralph Timmermann, G. Hilmar Gudmundsson, and Jan De Rydt
EGUsphere, https://doi.org/10.5194/egusphere-2024-648, https://doi.org/10.5194/egusphere-2024-648, 2024
Short summary
Short summary
The new coupled ice sheet-ocean model addresses challenges related to horizontal resolution through advanced mesh flexibility, enabled by the use of unstructured grids. We describe the new model, verify its functioning in an idealised setting and demonstrate its advantages in a global-ocean/Antarctic ice sheet domain. The results of this study comprise an important step towards improving predictions of the Antarctic contribution to sea level rise over centennial time scales.
Ole Zeising, Niklas Neckel, Nils Dörr, Veit Helm, Daniel Steinhage, Ralph Timmermann, and Angelika Humbert
The Cryosphere, 18, 1333–1357, https://doi.org/10.5194/tc-18-1333-2024, https://doi.org/10.5194/tc-18-1333-2024, 2024
Short summary
Short summary
The 79° North Glacier in Greenland has experienced significant changes over the last decades. Due to extreme melt rates, the ice has thinned significantly in the vicinity of the grounding line, where a large subglacial channel has formed since 2010. We attribute these changes to warm ocean currents and increased subglacial discharge from surface melt. However, basal melting has decreased since 2018, indicating colder water inflow into the cavity below the glacier.
Lukrecia Stulic, Ralph Timmermann, Stephan Paul, Rolf Zentek, Günther Heinemann, and Torsten Kanzow
Ocean Sci., 19, 1791–1808, https://doi.org/10.5194/os-19-1791-2023, https://doi.org/10.5194/os-19-1791-2023, 2023
Short summary
Short summary
In the southern Weddell Sea, the strong sea ice growth in coastal polynyas drives formation of dense shelf water. By using a sea ice–ice shelf–ocean model with representation of the changing icescape based on satellite data, we find that polynya sea ice growth depends on both the regional atmospheric forcing and the icescape. Not just strength but also location of the sea ice growth in polynyas affects properties of the dense shelf water and the basal melting of the Filchner–Ronne Ice Shelf.
Verena Haid, Ralph Timmermann, Özgür Gürses, and Hartmut H. Hellmer
Ocean Sci., 19, 1529–1544, https://doi.org/10.5194/os-19-1529-2023, https://doi.org/10.5194/os-19-1529-2023, 2023
Short summary
Short summary
Recently, it was found that cold-to-warm changes in Antarctic shelf sea areas are possible and lead to higher ice shelf melt rates. In modelling experiments, we found that if the highest density in front of the ice shelf becomes lower than the density of the warmer water off-shelf at the deepest access to the shelf, the off-shelf water will flow onto the shelf. Our results also indicate that this change will offer some, although not much, resistance to reversal and constitutes a tipping point.
Christoph Heinze, Thorsten Blenckner, Peter Brown, Friederike Fröb, Anne Morée, Adrian L. New, Cara Nissen, Stefanie Rynders, Isabel Seguro, Yevgeny Aksenov, Yuri Artioli, Timothée Bourgeois, Friedrich Burger, Jonathan Buzan, B. B. Cael, Veli Çağlar Yumruktepe, Melissa Chierici, Christopher Danek, Ulf Dieckmann, Agneta Fransson, Thomas Frölicher, Giovanni Galli, Marion Gehlen, Aridane G. González, Melchor Gonzalez-Davila, Nicolas Gruber, Örjan Gustafsson, Judith Hauck, Mikko Heino, Stephanie Henson, Jenny Hieronymus, I. Emma Huertas, Fatma Jebri, Aurich Jeltsch-Thömmes, Fortunat Joos, Jaideep Joshi, Stephen Kelly, Nandini Menon, Precious Mongwe, Laurent Oziel, Sólveig Ólafsdottir, Julien Palmieri, Fiz F. Pérez, Rajamohanan Pillai Ranith, Juliano Ramanantsoa, Tilla Roy, Dagmara Rusiecka, J. Magdalena Santana Casiano, Yeray Santana-Falcón, Jörg Schwinger, Roland Séférian, Miriam Seifert, Anna Shchiptsova, Bablu Sinha, Christopher Somes, Reiner Steinfeldt, Dandan Tao, Jerry Tjiputra, Adam Ulfsbo, Christoph Völker, Tsuyoshi Wakamatsu, and Ying Ye
Biogeosciences Discuss., https://doi.org/10.5194/bg-2023-182, https://doi.org/10.5194/bg-2023-182, 2023
Preprint under review for BG
Short summary
Short summary
For assessing the consequences of human-induced climate change for the marine realm, it is necessary to not only look at gradual changes but also at abrupt changes of environmental conditions. We summarise abrupt changes in ocean warming, acidification, and oxygen concentration as the key environmental factors for ecosystems. Taking these abrupt changes into account requires greenhouse gas emissions to be reduced to a larger extent than previously thought to limit respective damage.
Qiang Wang, Sergey Danilov, Longjiang Mu, Dmitry Sidorenko, and Claudia Wekerle
The Cryosphere, 15, 4703–4725, https://doi.org/10.5194/tc-15-4703-2021, https://doi.org/10.5194/tc-15-4703-2021, 2021
Short summary
Short summary
Using simulations, we found that changes in ocean freshwater content induced by wind perturbations can significantly affect the Arctic sea ice drift, thickness, concentration and deformation rates years after the wind perturbations. The impact is through changes in sea surface height and surface geostrophic currents and the most pronounced in warm seasons. Such a lasting impact might become stronger in a warming climate and implies the importance of ocean initialization in sea ice prediction.
Cara Nissen and Meike Vogt
Biogeosciences, 18, 251–283, https://doi.org/10.5194/bg-18-251-2021, https://doi.org/10.5194/bg-18-251-2021, 2021
Short summary
Short summary
Using a regional Southern Ocean ecosystem model, we find that the relative importance of Phaeocystis and diatoms at high latitudes is controlled by iron and temperature variability, with light levels controlling the seasonal succession in coastal areas. Yet, biomass losses via aggregation and grazing matter as well. We show that the seasonal succession of Phaeocystis and diatoms impacts the seasonality of carbon export fluxes with ramifications for nutrient cycling and food web dynamics.
Claudia Wekerle, Tore Hattermann, Qiang Wang, Laura Crews, Wilken-Jon von Appen, and Sergey Danilov
Ocean Sci., 16, 1225–1246, https://doi.org/10.5194/os-16-1225-2020, https://doi.org/10.5194/os-16-1225-2020, 2020
Short summary
Short summary
The high-resolution ocean models ROMS and FESOM configured for the Fram Strait reveal very energetic ocean conditions there. The two main currents meander strongly and shed circular currents of water, called eddies. Our analysis shows that this region is characterised by small and short-lived eddies (on average around a 5 km radius and 10 d lifetime). Both models agree on eddy properties and show similar patterns of baroclinic and barotropic instability of the West Spitsbergen Current.
Yoshihiro Nakayama, Ralph Timmermann, and Hartmut H. Hellmer
The Cryosphere, 14, 2205–2216, https://doi.org/10.5194/tc-14-2205-2020, https://doi.org/10.5194/tc-14-2205-2020, 2020
Short summary
Short summary
Previous studies have shown accelerations of West Antarctic glaciers, implying that basal melt rates of these glaciers were small and increased in the middle of the 20th century. We conduct coupled sea ice–ice shelf–ocean simulations with different levels of ice shelf melting from West Antarctic glaciers. This study reveals how far and how quickly glacial meltwater from ice shelves in the Amundsen and Bellingshausen seas propagates downstream into the Ross Sea and along the East Antarctic coast.
Felix L. Müller, Denise Dettmering, Claudia Wekerle, Christian Schwatke, Marcello Passaro, Wolfgang Bosch, and Florian Seitz
Earth Syst. Sci. Data, 11, 1765–1781, https://doi.org/10.5194/essd-11-1765-2019, https://doi.org/10.5194/essd-11-1765-2019, 2019
Short summary
Short summary
Polar regions by satellite-altimetry-derived geostrophic currents (GCs) suffer from irregular and sparse data coverage. Therefore, a new dataset is presented, combining along-track derived dynamic ocean topography (DOT) heights with simulated differential water heights. For this purpose, a combination method, based on principal component analysis, is used. The results are combined with spatio-temporally consistent DOT and derived GC representations on unstructured, triangular formulated grids.
Felix L. Müller, Claudia Wekerle, Denise Dettmering, Marcello Passaro, Wolfgang Bosch, and Florian Seitz
The Cryosphere, 13, 611–626, https://doi.org/10.5194/tc-13-611-2019, https://doi.org/10.5194/tc-13-611-2019, 2019
Short summary
Short summary
Knowledge of the dynamic ocean topography (DOT) enables studying changes of ocean surface currents. The DOT can be derived by satellite altimetry measurements or by models. However, in polar regions, altimetry-derived sea surface heights are affected by sea ice. Model representations are consistent but impacted by the underlying functional backgrounds and forcing models. The present study compares results from both data sources in order to investigate the potential for a combination of the two.
Cara Nissen, Meike Vogt, Matthias Münnich, Nicolas Gruber, and F. Alexander Haumann
Biogeosciences, 15, 6997–7024, https://doi.org/10.5194/bg-15-6997-2018, https://doi.org/10.5194/bg-15-6997-2018, 2018
Short summary
Short summary
Using a regional ocean model, we find that coccolithophore biomass in the Southern Ocean is highest in the subantarctic in late summer when diatom growth becomes limited by silicate. We show that zooplankton grazing is crucial to explain phytoplankton biomass distributions in this area and conclude that assessments of future distributions should not only consider physical and chemical factors (temperature, light, nutrients, pH), but also interactions with other phytoplankton or zooplankton.
Maren Elisabeth Richter, Wilken-Jon von Appen, and Claudia Wekerle
Ocean Sci., 14, 1147–1165, https://doi.org/10.5194/os-14-1147-2018, https://doi.org/10.5194/os-14-1147-2018, 2018
Short summary
Short summary
In the Fram Strait, Arctic Ocean outflow is joined by Atlantic Water (AW) that has not flowed through the Arctic Ocean. The confluence creates a density gradient which steepens and draws closer to the east Greenland shelf break from N to S. This brings the warm AW closer to the shelf break. South of 79° N, AW has reached the shelf break and the East Greenland Current has formed. When AW reaches the Greenland shelf it may propagate through troughs to glacier termini and contribute to glacier melt.
Kaitlin A. Naughten, Katrin J. Meissner, Benjamin K. Galton-Fenzi, Matthew H. England, Ralph Timmermann, Hartmut H. Hellmer, Tore Hattermann, and Jens B. Debernard
Geosci. Model Dev., 11, 1257–1292, https://doi.org/10.5194/gmd-11-1257-2018, https://doi.org/10.5194/gmd-11-1257-2018, 2018
Short summary
Short summary
MetROMS and FESOM are two ocean/sea-ice models which resolve Antarctic ice-shelf cavities and consider thermodynamics at the ice-shelf base. We simulate the period 1992–2016 with both models, and with two options for resolution in FESOM, and compare output from the three simulations. Ice-shelf melt rates, sub-ice-shelf circulation, continental shelf water masses, and sea-ice processes are compared and evaluated against available observations.
Qiang Wang, Claudia Wekerle, Sergey Danilov, Xuezhu Wang, and Thomas Jung
Geosci. Model Dev., 11, 1229–1255, https://doi.org/10.5194/gmd-11-1229-2018, https://doi.org/10.5194/gmd-11-1229-2018, 2018
Short summary
Short summary
For developing a system for Arctic research, we evaluate the Arctic Ocean simulated by FESOM. We use two global meshes differing in the horizontal resolution only in the Arctic Ocean (24 vs. 4.5 km). The high resolution significantly improves the model's representation of the Arctic Ocean. The most pronounced improvement is in the Arctic intermediate layer. The high resolution also improves the ocean surface circulation, mainly through a better representation of the Canadian Arctic Archipelago.
Ralph Timmermann and Sebastian Goeller
Ocean Sci., 13, 765–776, https://doi.org/10.5194/os-13-765-2017, https://doi.org/10.5194/os-13-765-2017, 2017
Short summary
Short summary
A coupled model has been developed to study the interaction between the ocean and the Antarctic ice sheet. Simulations for present-day climate yield realistic ice-shelf melt rates and a grounding line position close to the observed state. In a warm-water-inflow scenario, the model suggests a substantial thinning of the ice shelf and a local retreat of the grounding line. The coupled model yields a stronger increase in ice-shelf basal melt rates than a fixed-geometry control experiment.
Janin Schaffer, Ralph Timmermann, Jan Erik Arndt, Steen Savstrup Kristensen, Christoph Mayer, Mathieu Morlighem, and Daniel Steinhage
Earth Syst. Sci. Data, 8, 543–557, https://doi.org/10.5194/essd-8-543-2016, https://doi.org/10.5194/essd-8-543-2016, 2016
Short summary
Short summary
The RTopo-2 data set provides consistent maps of global ocean bathymetry and ice surface topographies for Greenland and Antarctica at 30 arcsec grid spacing. We corrected data from earlier products in the areas of Petermann, Hagen Bræ, and Helheim glaciers, incorporated original data for the floating ice tongue of Nioghalvfjerdsfjorden Glacier, and applied corrections for the geometry of Getz, Abbot, and Fimbul ice shelf cavities. The data set is available from the PANGAEA database.
S. L. Cornford, D. F. Martin, A. J. Payne, E. G. Ng, A. M. Le Brocq, R. M. Gladstone, T. L. Edwards, S. R. Shannon, C. Agosta, M. R. van den Broeke, H. H. Hellmer, G. Krinner, S. R. M. Ligtenberg, R. Timmermann, and D. G. Vaughan
The Cryosphere, 9, 1579–1600, https://doi.org/10.5194/tc-9-1579-2015, https://doi.org/10.5194/tc-9-1579-2015, 2015
Short summary
Short summary
We used a high-resolution ice sheet model capable of resolving grounding line dynamics (BISICLES) to compute responses of the major West Antarctic ice streams to projections of ocean and atmospheric warming. This is computationally demanding, and although other groups have considered parts of West Antarctica, we think this is the first calculation for the whole region at the sub-kilometer resolution that we show is required.
S. Danilov, Q. Wang, R. Timmermann, N. Iakovlev, D. Sidorenko, M. Kimmritz, T. Jung, and J. Schröter
Geosci. Model Dev., 8, 1747–1761, https://doi.org/10.5194/gmd-8-1747-2015, https://doi.org/10.5194/gmd-8-1747-2015, 2015
Short summary
Short summary
Unstructured meshes allow multi-resolution modeling of ocean dynamics. Sea ice models formulated on unstructured meshes are a necessary component of ocean models intended for climate studies. This work presents a description of a finite-element sea ice model which is used as a component of a finite-element sea ice ocean circulation model. The principles underlying its design can be of interest to other groups pursuing ocean modelling on unstructured meshes.
A. Levermann, R. Winkelmann, S. Nowicki, J. L. Fastook, K. Frieler, R. Greve, H. H. Hellmer, M. A. Martin, M. Meinshausen, M. Mengel, A. J. Payne, D. Pollard, T. Sato, R. Timmermann, W. L. Wang, and R. A. Bindschadler
Earth Syst. Dynam., 5, 271–293, https://doi.org/10.5194/esd-5-271-2014, https://doi.org/10.5194/esd-5-271-2014, 2014
Q. Wang, S. Danilov, D. Sidorenko, R. Timmermann, C. Wekerle, X. Wang, T. Jung, and J. Schröter
Geosci. Model Dev., 7, 663–693, https://doi.org/10.5194/gmd-7-663-2014, https://doi.org/10.5194/gmd-7-663-2014, 2014
Related subject area
Approach: Numerical Models | Properties and processes: Overturning circulation, gyres and water masses
North Atlantic Subtropical Mode Water properties: intrinsic and atmospherically forced interannual variability
The formation and ventilation of an oxygen minimum zone in a simple model for latitudinally alternating zonal jets
Long-term Variability and Trends of Agulhas Leakage and its Impacts on the Global Overturning
Persistent climate model biases in the Atlantic Ocean's freshwater transport
Surface factors controlling the volume of accumulated Labrador Sea Water
Dependency of simulated tropical Atlantic current variability on the wind forcing
Assessing the drift of fish aggregating devices in the tropical Pacific Ocean
Assessment of Indonesian Throughflow transports from ocean reanalyses with mooring-based observations
Olivier Narinc, Thierry Penduff, Guillaume Maze, Stéphanie Leroux, and Jean-Marc Molines
Ocean Sci., 20, 1351–1365, https://doi.org/10.5194/os-20-1351-2024, https://doi.org/10.5194/os-20-1351-2024, 2024
Short summary
Short summary
This study examines how the ocean's chaotic variability and atmospheric fluctuations affect yearly changes in North Atlantic Subtropical Mode Water (STMW) properties, using an ensemble of realistic ocean simulations. Results show that while yearly changes in STMW properties are mostly paced by the atmosphere, a notable part of these changes are random in phase. This study also illustrates the value of ensemble simulations over single runs in understanding oceanic fluctuations and their causes.
Eike E. Köhn, Richard J. Greatbatch, Peter Brandt, and Martin Claus
Ocean Sci., 20, 1281–1290, https://doi.org/10.5194/os-20-1281-2024, https://doi.org/10.5194/os-20-1281-2024, 2024
Short summary
Short summary
The latitudinally alternating zonal jets are a ubiquitous feature of the ocean. We use a simple model to illustrate the potential role of these jets in the formation, maintenance, and multidecadal variability in the oxygen minimum zones, using the eastern tropical North Atlantic oxygen minimum zone as an example.
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.
René M. van Westen and Henk A. Dijkstra
Ocean Sci., 20, 549–567, https://doi.org/10.5194/os-20-549-2024, https://doi.org/10.5194/os-20-549-2024, 2024
Short summary
Short summary
The Atlantic Meridional Overturning Circulation (AMOC) is an important component in the global climate system. Observations of the present-day AMOC indicate that it may weaken or collapse under global warming, with profound disruptive effects on future climate. However, AMOC weakening is not correctly represented because an important feedback is underestimated due to biases in the Atlantic's freshwater budget. Here we address these biases in several state-of-the-art climate model simulations.
Yavor Kostov, Marie-José Messias, Herlé Mercier, David P. Marshall, and Helen L. Johnson
Ocean Sci., 20, 521–547, https://doi.org/10.5194/os-20-521-2024, https://doi.org/10.5194/os-20-521-2024, 2024
Short summary
Short summary
We examine factors affecting variability in the volume of Labrador Sea Water (LSW), a water mass that is important for the uptake and storage of heat and carbon in the Atlantic Ocean. We find that LSW accumulated in the Labrador Sea exhibits a lagged response to remote conditions: surface wind stress, heat flux, and freshwater flux anomalies, especially along the pathways of the North Atlantic Current branches. We use our results to reconstruct and attribute historical changes in LSW volume.
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.
Philippe F. V. W. Frankemölle, Peter D. Nooteboom, Joe Scutt Phillips, Lauriane Escalle, Simon Nicol, and Erik van Sebille
Ocean Sci., 20, 31–41, https://doi.org/10.5194/os-20-31-2024, https://doi.org/10.5194/os-20-31-2024, 2024
Short summary
Short summary
Tuna fisheries in the Pacific often use drifting fish aggregating devices (dFADs) to attract fish that are advected by subsurface flow through underwater appendages. Using a particle advection model, we find that virtual particles advected by surface flow are displaced farther than virtual dFADs. We find a relation between El Niño–Southern Oscillation and circular motion in some areas, influencing dFAD densities. This information helps us to understand processes that drive dFAD distribution.
Magdalena Fritz, Michael Mayer, Leopold Haimberger, and Susanna Winkelbauer
Ocean Sci., 19, 1203–1223, https://doi.org/10.5194/os-19-1203-2023, https://doi.org/10.5194/os-19-1203-2023, 2023
Short summary
Short summary
The interaction between the Indonesian Throughflow (ITF) and regional climate phenomena indicates the high relevance for monitoring the ITF. Observations remain temporally and spatially limited; hence near-real-time monitoring is only possible with reanalyses. We assess how well ocean reanalyses depict the intensity of the ITF via comparison to observations. The results show that reanalyses agree reasonably well with in situ observations; however, some aspects require higher-resolution products.
Cited articles
Abrahamsen, E. P., Meijers, A. J. S., Polzin, K. L., Garabato, A. C. N., King, B. A., Firing, Y. L., Sallée, J.-B., Sheen, K. L., Gordon, A. L., Huber, B. A., and Meredith, M. P.: Stabilization of dense Antarctic water supply to the Atlantic Ocean overturning circulation, Nat. Clim. Change, 9, 742–746, https://doi.org/10.1038/s41558-019-0561-2, 2019. a, b, c
Absy, J., Schröder, M., Muench, R., and Hellmer, H.: Early summer thermohaline characteristics and mixing in the western Weddell Sea, Deep-Sea Res. Pt. II, 55, 1117–1131, https://doi.org/10.1016/j.dsr2.2007.12.023, 2008. a
Akhoudas, C., Sallée, J.-B., Reverdin, G., Aloisi, G., Benetti, M., Vignes, L., and Gelado, M.: Ice Shelf Basal Melt and Influence on Dense Water Outflow in the Southern Weddell Sea, J. Geophys. Res.-Oceans, 125, 1–19, https://doi.org/10.1029/2019JC015710, 2020. a
Akhoudas, C., Sallée, J.-B., Haumann, F. A., Meredith, M. P., Garabato, A. N., Reverdin, G., Jullion, L., Aloisi, G., Benetti, M., Leng, M. J., and Arrowsmith, C.: Ventilation of the abyss in the Atlantic sector of the Southern Ocean, Sci. Rep.-UK, 11, 6760, https://doi.org/10.1038/s41598-021-86043-2, 2021. a
Caccavo, J., Ashford, J., Ryan, S., Papetti, C., Schröder, M., and Zane, L.: Spatial structuring and life history connectivity of Antarctic silverfish along the southern continental shelf of the Weddell Sea, Mar. Ecol. Prog. Ser., 624, 195–212, https://doi.org/10.3354/meps13017, 2019. a, b
Danilov, S., Wang, Q., Timmermann, R., Iakovlev, N., Sidorenko, D., Kimmritz, M., Jung, T., and Schröter, J.: Finite-Element Sea Ice Model (FESIM), version 2, Geosci. Model Dev., 8, 1747–1761, https://doi.org/10.5194/gmd-8-1747-2015, 2015. a
Darelius, E. and Sallée, J. B.: Seasonal Outflow of Ice Shelf Water Across the Front of the Filchner Ice Shelf, Weddell Sea, Antarctica, Geophys. Res. Lett., 45, 3577–3585, https://doi.org/10.1002/2017GL076320, 2018. a
Darelius, E., Makinson, K., Daae, K., Fer, I., Holland, P. R., and Nicholls, K. W.: Hydrography and circulation in the Filchner Depression, Weddell Sea, Antarctica, J. Geophys. Res.-Oceans, 119, 5797–5814, https://doi.org/10.1002/2014JC010225, 2014. a, b
Darelius, E., Daae, K., Dundas, V., Fer, I., Hellmer, H. H., Janout, M., Nicholls, K. W., Sallée, J.-B., and Østerhus, S.: Observational evidence for on-shelf heat transport driven by dense water export in the Weddell Sea, Nat. Commun., 14, 1022, https://doi.org/10.1038/s41467-023-36580-3, 2023. a, b
Davis, P. E. D., Jenkins, A., Nicholls, K. W., Dutrieux, P., Schröder, M., Janout, M. A., Hellmer, H. H., Templeton, R., and McPhail, S.: Observations of Modified Warm Deep Water Beneath Ronne Ice Shelf, Antarctica, From an Autonomous Underwater Vehicle, J. Geophys. Res.-Oceans, 127, e2022JC019103, https://doi.org/10.1029/2022JC019103, 2022. a
Fahrbach, E., Rohardt, G., Schröder, M., and Strass, V.: Transport and structure of the Weddell Gyre, Ann. Geophys., 12, 840–855, https://doi.org/10.1007/s00585-994-0840-7, 1994. a
Foldvik, A., Gammelsrød, T., and Tørresen, T.: Circulation and water masses on the southern Weddell Sea shelf, Oceanology of the Antarctic Continental Shelf, Vol. 43, American Geophysical Union, 5–20, 1985. a
Foster, T. D. and Carmack, E. C.: Frontal zone mixing and Antarctic Bottom water formation in the southern Weddell Sea, Deep Sea Research and Oceanographic Abstracts, 23, 301–317, https://doi.org/10.1016/0011-7471(76)90872-X, 1976. a
Haid, V., Timmermann, R., Gürses, Ö., and Hellmer, H. H.: On the drivers of regime shifts in the Antarctic marginal seas, EGUsphere [preprint], https://doi.org/10.5194/egusphere-2022-1044, 2022. a
Hellmer, H. H., Kauker, F., Timmermann, R., Determann, J., and Rae, J.: Twenty-first-century warming of a large Antarctic ice-shelf cavity by a redirected coastal current, Nature, 485, 225–228, https://doi.org/10.1038/nature11064, 2012. a, b, c, d
Hellmer, H. H., Kauker, F., Timmermann, R., and Hattermann, T.: The Fate of the Southern Weddell Sea Continental Shelf in a Warming Climate, J. Climate, 30, 4337–4350, https://doi.org/10.1175/JCLI-D-16-0420.1, 2017. a, b
Hersbach, H., Bell, B., Berrisford, P., Biavati, G., Horányi, A., Muñoz Sabater, J., Nicolas, J., Peubey, C., Radu, R., Rozum, I., Schepers, D., Simmons, A., Soci, C., Dee, D., and Thépaut, J.-N.: ERA5 hourly data on single levels from 1940 to present, Copernicus Climate Change Service (C3S) Climate Data Store (CDS), https://doi.org/10.24381/cds.adbb2d47, 2023. a
Jacobs, S. S.: Bottom water production and its links with the thermohaline circulation, Antarct. Sci., 16, 427–437, https://doi.org/10.1017/S095410200400224X, 2004. a, b, c
Janout, M. A., Hellmer, H. H., Hattermann, T., Huhn, O., Sültenfuss, J., Østerhus, S., Stulic, L., Ryan, S., Schröder, M., and Kanzow, T.: FRIS Revisited in 2018: On the Circulation and Water Masses at the Filchner and Ronne Ice Shelves in the Southern Weddell Sea, J. Geophys. Res.-Oceans, 126, 1–19, https://doi.org/10.1029/2021JC017269, 2021. a, b
Llanillo, P. J., Kanzow, T., Janout, M. A., and Rohardt, G.: The Deep-Water Plume in the Northwestern Weddell Sea, Antarctica: Mean State, Seasonal Cycle and Interannual Variability Influenced by Climate Modes, J. Geophys. Res.-Oceans, 128, 1–22, https://doi.org/10.1029/2022JC019375, 2023. a, b, c
Marshall, J. and Speer, K.: Closure of the meridional overturning circulation through Southern Ocean upwelling, Nat. Geosci., 5, 171–180, https://doi.org/10.1038/ngeo1391, 2012. a
Marshall, J., Hill, C., Perelman, L., and Adcroft, A.: Hydrostatic, quasi-hydrostatic, and nonhydrostatic ocean modeling, J. Geophys. Res.-Oceans, 102, 5733–5752, https://doi.org/10.1029/96JC02776, 1997. a
Meredith, M. P., Locarnini, R. A., Van Scoy, K. A., Watson, A. J., Heywood, K. J., and King, B. A.: On the sources of Weddell Gyre Antarctic Bottom Water, J. Geophys. Res.-Oceans, 105, 1093–1104, https://doi.org/10.1029/1999JC900263, 2000. a
Morrison, A. K., Hogg, A. M., England, M. H., and Spence, P.: Warm Circumpolar Deep Water transport toward Antarctica driven by local dense water export in canyons, Sci. Adv., 6, eaav2516, https://doi.org/10.1126/sciadv.aav2516, 2020. a
Naughten, K. A., De Rydt, J., Rosier, S. H. R., Jenkins, A., Holland, P. R., and Ridley, J. K.: Two-timescale response of a large Antarctic ice shelf to climate change, Nat. Commun., 12, 1991, https://doi.org/10.1038/s41467-021-22259-0, 2021. a
Nicholls, K. W., Padman, L., Schröder, M., Woodgate, R., Jenkins, A., and Østerhus, S.: Water mass modification over the continental shelf north of Ronne Ice Shelf, Antarctica, J. Geophys. Res., 108, 3260, https://doi.org/10.1029/2002JC001713, 2003. a
Nicholls, K. W., Østerhus, S., Makinson, K., Gammelsrød, T., and Fahrbach, E.: Ice-ocean processes over the continental shelf of the southern Weddell Sea, Antarctica: A review, Rev. Geophys., 47, RG3003, https://doi.org/10.1029/2007RG000250, 2009. a, b
Nissen, C.: FESOM-REcoM model data: Lagrangian particle trajectories, Zenodo [data set], https://doi.org/10.5281/zenodo.8051366, 2023. a
Nissen, C., Hauck, J., Hoppema, M., Timmermann, R., and Gürses, O.: HighRes_highLat_SO FESOM1.4-REcoM2 model simulations to project future change in the coupled physical-biogeochemical system simA historical variableAtmCO2 variableClimate, World Data Center for Climate (WDCC) at DKRZ [data set], https://doi.org/10.26050/WDCC/FESOM14-REcoM2_A_hist_vA_vC, 2023a. a
Nissen, C., Hauck, J., Hoppema, M., Timmermann, R., and Gürses, O.: HighRes_highLat_SO FESOM1.4-REcoM2 model simulations to project future change in the coupled physical-biogeochemical system simA SSP585 variableAtmCO2 variableClimate, World Data Center for Climate (WDCC) at DKRZ [data set], https://doi.org/10.26050/WDCC/FESOM14-REcoM2_A_s585_vA_vC, 2023b. a
Nissen, C., Timmermann, R., Hoppema, M., and Hauck, J.: A Regime Shift on Weddell Sea Continental Shelves with Local and Remote Physical and Biogeochemical Implications is Avoidable in a 2 ∘C Scenario, J. Climate, 36, 6613–6630, https://doi.org/10.1175/JCLI-D-22-0926.1, 2023c. a, b, c, d, e, f, g, h, i, j, k, l
Nøst, O. A. and Østerhus, S.: Impact of Grounded Icebergs on the Hydrographic Conditions Near the Filchner Ice Shelf, in: Ocean, Ice, and Atmosphere: Interactions at the Antarctic Continental Margin, American Geophysical Union (AGU), 267–284, https://doi.org/10.1029/AR075p0267, 1985. a
Purser, A., Hehemann, L., Boehringer, L., Tippenhauer, S., Wege, M., Bornemann, H., Pineda-Metz, S. E., Flintrop, C. M., Koch, F., Hellmer, H. H., Burkhardt-Holm, P., Janout, M., Werner, E., Glemser, B., Balaguer, J., Rogge, A., Holtappels, M., and Wenzhoefer, F.: A vast icefish breeding colony discovered in the Antarctic, Curr. Biol., 32, 842–850.e4, https://doi.org/10.1016/j.cub.2021.12.022, 2022. a
Reeve, K. A., Boebel, O., Strass, V., Kanzow, T., and Gerdes, R.: Horizontal circulation and volume transports in the Weddell Gyre derived from Argo float data, Prog. Oceanogr., 175, 263–283, https://doi.org/10.1016/j.pocean.2019.04.006, 2019. a
Ryan, S., Hellmer, H. H., Janout, M., Darelius, E., Vignes, L., and Schröder, M.: Exceptionally Warm and Prolonged Flow of Warm Deep Water Toward the Filchner-Ronne Ice Shelf in 2017, Geophys. Res. Lett., 47, e2020GL088119, https://doi.org/10.1029/2020GL088119, 2020. a, b, c, d
Schaffer, J., Timmermann, R., Arndt, J. E., Kristensen, S. S., Mayer, C., Morlighem, M., and Steinhage, D.: A global, high-resolution data set of ice sheet topography, cavity geometry, and ocean bathymetry, Earth Syst. Sci. Data, 8, 543–557, https://doi.org/10.5194/essd-8-543-2016, 2016. a
Semmler, T., Danilov, S., Gierz, P., Goessling, H. F., Hegewald, J., Hinrichs, C., Koldunov, N., Khosravi, N., Mu, L., Rackow, T., Sein, D. V., Sidorenko, D., Wang, Q., and Jung, T.: Simulations for CMIP6 with the AWI Climate Model AWI-CM-1-1, J. Adv. Model. Earth Sy., 12, 1–34, https://doi.org/10.1029/2019MS002009, 2020. a, b
Talley, L.: Closure of the Global Overturning Circulation Through the Indian, Pacific, and Southern Oceans: Schematics and Transports, Oceanography, 26, 80–97, https://doi.org/10.5670/oceanog.2013.07, 2013. a
Tamsitt, V., England, M. H., Rintoul, S. R., and Morrison, A. K.: Residence Time and Transformation of Warm Circumpolar Deep Water on the Antarctic Continental Shelf, Geophys. Res. Lett., 48, 1–10, https://doi.org/10.1029/2021GL096092, 2021. a, b, c, d
Thompson, A. F., Stewart, A. L., Spence, P., and Heywood, K. J.: The Antarctic Slope Current in a Changing Climate, Rev. Geophys., 56, 741–770, https://doi.org/10.1029/2018RG000624, 2018. a
Timmermann, R. and Goeller, S.: Response to Filchner–Ronne Ice Shelf cavity warming in a coupled ocean–ice sheet model – Part 1: The ocean perspective, Ocean Sci., 13, 765–776, https://doi.org/10.5194/os-13-765-2017, 2017. a
Timmermann, R. and Hellmer, H. H.: Southern Ocean warming and increased ice shelf basal melting in the twenty-first and twenty-second centuries based on coupled ice-ocean finite-element modelling, Ocean Dynam., 63, 1011–1026, https://doi.org/10.1007/s10236-013-0642-0, 2013. a, b
Timmermann, R., Wang, Q., and Hellmer, H.: Ice-shelf basal melting in a global finite-element sea-ice/ice-shelf/ocean model, Ann. Glaciol., 53, 303–314, https://doi.org/10.3189/2012AoG60A156, 2012. a
Wang, Q., Danilov, S., Sidorenko, D., Timmermann, R., Wekerle, C., Wang, X., Jung, T., and Schröter, J.: The Finite Element Sea Ice-Ocean Model (FESOM) v.1.4: formulation of an ocean general circulation model, Geosci. Model Dev., 7, 663–693, https://doi.org/10.5194/gmd-7-663-2014, 2014. a, b, c, d
Wekerle, C., Krumpen, T., Dinter, T., von Appen, W.-J., Iversen, M. H., and Salter, I.: Properties of Sediment Trap Catchment Areas in Fram Strait: Results From Lagrangian Modeling and Remote Sensing, Front. Mar. Sci., 5, 1–16, https://doi.org/10.3389/fmars.2018.00407, 2018. a
Short summary
The southeastern Weddell Sea is important for global ocean circulation due to the cross-shelf-break exchange of Dense Shelf Water and Warm Deep Water, but their exact circulation pathways remain elusive. Using Lagrangian model experiments in an eddy-permitting ocean model, we show how present circulation pathways and transit times of these water masses on the continental shelf are altered by 21st-century climate change, which has implications for local ice-shelf basal melt rates and ecosystems.
The southeastern Weddell Sea is important for global ocean circulation due to the...
