Articles | Volume 21, issue 1
https://doi.org/10.5194/os-21-261-2025
© Author(s) 2025. 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-21-261-2025
© Author(s) 2025. This work is distributed under
the Creative Commons Attribution 4.0 License.
the Creative Commons Attribution 4.0 License.
Research article
| 
29 Jan 2025
Research article |
| 29 Jan 2025
| 29 Jan 2025
Dynamics of salt intrusion in complex estuarine networks: an idealised model applied to the Rhine–Meuse Delta
Department of Physics, Institute for Marine and Atmospheric Research Utrecht, Utrecht University, Utrecht, the Netherlands
Wouter M. Kranenburg
Deltares, Delft, the Netherlands
Department of Hydraulic Engineering, Delft University of Technology, Delft, the Netherlands
Ymkje Huismans
Deltares, Delft, the Netherlands
Department of Hydraulic Engineering, Delft University of Technology, Delft, the Netherlands
Huib E. de Swart
Department of Physics, Institute for Marine and Atmospheric Research Utrecht, Utrecht University, Utrecht, the Netherlands
Henk A. Dijkstra
Department of Physics, Institute for Marine and Atmospheric Research Utrecht, Utrecht University, Utrecht, the Netherlands
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René M. van Westen, Elian Vanderborght, and Henk A. Dijkstra
EGUsphere, https://doi.org/10.5194/egusphere-2025-14, https://doi.org/10.5194/egusphere-2025-14, 2025
This preprint is open for discussion and under review for Earth System Dynamics (ESD).
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The Atlantic Meridional Overturning Circulation (AMOC) is a tipping element in the fully-coupled Community Earth System Model (CESM). Under varying freshwater flux forcing parameters or climate change, the AMOC may collapse from a relatively strong state to a substantially weaker state. It is important to understand the dynamics of the AMOC collapse in the CESM. We show that the stability of the AMOC in the CESM is controlled by only a few feedback processes.
Aurora Faure Ragani and Henk A. Dijkstra
EGUsphere, https://doi.org/10.5194/egusphere-2025-45, https://doi.org/10.5194/egusphere-2025-45, 2025
This preprint is open for discussion and under review for Earth System Dynamics (ESD).
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The Atlantic Meridional Overturning Circulation (AMOC) is sensitive to changing surface forcing conditions. Under future greenhouse gas emission reductions, it was shown in a conceptual model that it may be possible to avoid a collapse of the AMOC. Using a detailed global ocean model, we clarify the physics of the collapse and recovery behaviour of the AMOC. The potential to avoid an AMOC collapse is tightly linked to a delicate balance of salt fluxes in the northern North Atlantic.
Amber A. Boot and Henk A. Dijkstra
Earth Syst. Dynam., 16, 115–150, https://doi.org/10.5194/esd-16-115-2025, https://doi.org/10.5194/esd-16-115-2025, 2025
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The ocean is forced at the surface by a heat flux and a freshwater flux. This noise can influence long-term ocean variability and large-scale circulation. Here we study noise characteristics in reanalysis data for these fluxes. We try to capture the noise characteristics by using several noise models and compare these to state-of-the-art climate models. A pointwise noise model performs better than the climate models and can be used as forcing in ocean-only models.
Amber A. Boot, Anna S. von der Heydt, and Henk A. Dijkstra
Earth Syst. Dynam., 15, 1567–1590, https://doi.org/10.5194/esd-15-1567-2024, https://doi.org/10.5194/esd-15-1567-2024, 2024
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We investigate the multiple equilibria window (MEW) of the Atlantic Meridional Overturning Circulation (AMOC) within a box model. We find that increasing the total carbon content of the system widens the MEW of the AMOC. The important mechanisms at play are the balance between the source and sink of carbon and the sensitivity of the AMOC to freshwater forcing over the Atlantic Ocean. Our results suggest that changes in the marine carbon cycle can influence AMOC stability in future climates.
Francesco Guardamagna, Claudia Wieners, and Henk Dijkstra
Nonlin. Processes Geophys. Discuss., https://doi.org/10.5194/npg-2024-24, https://doi.org/10.5194/npg-2024-24, 2024
Preprint under review for NPG
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Artificial intelligence (AI) has recently shown promising results in ENSO (El Niño Southern Oscillation) forecasting, outperforming traditional models. Yet, AI models deliver accurate predictions without showing the underlying mechanisms. Our study examines a specific AI model, the Reservoir Computer (RC). Our results show that the RC is less sensitive to initial perturbations than the traditional Zebiak and Cane (ZC) model. This reduced sensitivity can explain the RC's superior skills.
Arthur Merlijn Oldeman, Michiel L. J. Baatsen, Anna S. von der Heydt, Frank M. Selten, and Henk A. Dijkstra
Earth Syst. Dynam., 15, 1037–1054, https://doi.org/10.5194/esd-15-1037-2024, https://doi.org/10.5194/esd-15-1037-2024, 2024
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We might be able to constrain uncertainty in future climate projections by investigating variations in the climate of the past. In this study, we investigate the interactions of climate variability between the tropical Pacific (El Niño) and the North Pacific in a warm past climate – the mid-Pliocene, a period roughly 3 million years ago. Using model simulations, we find that, although the variability in El Niño was reduced, the variability in the North Pacific atmosphere was not.
Sacha Sinet, Peter Ashwin, Anna S. von der Heydt, and Henk A. Dijkstra
Earth Syst. Dynam., 15, 859–873, https://doi.org/10.5194/esd-15-859-2024, https://doi.org/10.5194/esd-15-859-2024, 2024
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Some components of the Earth system may irreversibly collapse under global warming. Among them, the Atlantic Meridional Overturning Circulation (AMOC), the Greenland Ice Sheet, and West Antarctica Ice Sheet are of utmost importance for maintaining the present-day climate. In a simplified model, we show that both the rate of ice melting and the natural variability linked to freshwater fluxes over the Atlantic Ocean drastically affect how an ice sheet collapse impacts the AMOC stability.
Julia E. Weiffenbach, Henk A. Dijkstra, Anna S. von der Heydt, Ayako Abe-Ouchi, Wing-Le Chan, Deepak Chandan, Ran Feng, Alan M. Haywood, Stephen J. Hunter, Xiangyu Li, Bette L. Otto-Bliesner, W. Richard Peltier, Christian Stepanek, Ning Tan, Julia C. Tindall, and Zhongshi Zhang
Clim. Past, 20, 1067–1086, https://doi.org/10.5194/cp-20-1067-2024, https://doi.org/10.5194/cp-20-1067-2024, 2024
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Elevated atmospheric CO2 concentrations and a smaller Antarctic Ice Sheet during the mid-Pliocene (~ 3 million years ago) cause the Southern Ocean surface to become fresher and warmer, which affects the global ocean circulation. The CO2 concentration and the smaller Antarctic Ice Sheet both have a similar and approximately equal impact on the Southern Ocean. The conditions of the Southern Ocean in the mid-Pliocene could therefore be analogous to those in a future climate with smaller ice sheets.
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
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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.
Arthur Merlijn Oldeman, Michiel L. J. Baatsen, Anna S. von der Heydt, Aarnout J. van Delden, and Henk A. Dijkstra
Weather Clim. Dynam., 5, 395–417, https://doi.org/10.5194/wcd-5-395-2024, https://doi.org/10.5194/wcd-5-395-2024, 2024
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The mid-Pliocene, a geological period around 3 million years ago, is sometimes considered the best analogue for near-future climate. It saw similar CO2 concentrations to the present-day but also a slightly different geography. In this study, we use climate model simulations and find that the Northern Hemisphere winter responds very differently to increased CO2 or to the mid-Pliocene geography. Our results weaken the potential of the mid-Pliocene as a future climate analogue.
Michiel Baatsen, Peter Bijl, Anna von der Heydt, Appy Sluijs, and Henk Dijkstra
Clim. Past, 20, 77–90, https://doi.org/10.5194/cp-20-77-2024, https://doi.org/10.5194/cp-20-77-2024, 2024
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This work introduces the possibility and consequences of monsoons on Antarctica in the warm Eocene climate. We suggest that such a monsoonal climate can be important to understand conditions in Antarctica prior to large-scale glaciation. We can explain seemingly contradictory indications of ice and vegetation on the continent through regional variability. In addition, we provide a new mechanism through which most of Antarctica remained ice-free through a wide range of global climatic changes.
Sina Loriani, Yevgeny Aksenov, David Armstrong McKay, Govindasamy Bala, Andreas Born, Cristiano M. Chiessi, Henk Dijkstra, Jonathan F. Donges, Sybren Drijfhout, Matthew H. England, Alexey V. Fedorov, Laura Jackson, Kai Kornhuber, Gabriele Messori, Francesco Pausata, Stefanie Rynders, Jean-Baptiste Salée, Bablu Sinha, Steven Sherwood, Didier Swingedouw, and Thejna Tharammal
EGUsphere, https://doi.org/10.5194/egusphere-2023-2589, https://doi.org/10.5194/egusphere-2023-2589, 2023
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In this work, we draw on paleoreords, observations and modelling studies to review tipping points in the ocean overturning circulations, monsoon systems and global atmospheric circulations. We find indications for tipping in the ocean overturning circulations and the West African monsoon, with potentially severe impacts on the Earth system and humans. Tipping in the other considered systems is considered conceivable but currently not sufficiently supported by evidence.
Valérian Jacques-Dumas, René M. van Westen, Freddy Bouchet, and Henk A. Dijkstra
Nonlin. Processes Geophys., 30, 195–216, https://doi.org/10.5194/npg-30-195-2023, https://doi.org/10.5194/npg-30-195-2023, 2023
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Computing the probability of occurrence of rare events is relevant because of their high impact but also difficult due to the lack of data. Rare event algorithms are designed for that task, but their efficiency relies on a score function that is hard to compute. We compare four methods that compute this function from data and measure their performance to assess which one would be best suited to be applied to a climate model. We find neural networks to be most robust and flexible for this task.
Julia E. Weiffenbach, Michiel L. J. Baatsen, Henk A. Dijkstra, Anna S. von der Heydt, Ayako Abe-Ouchi, Esther C. Brady, Wing-Le Chan, Deepak Chandan, Mark A. Chandler, Camille Contoux, Ran Feng, Chuncheng Guo, Zixuan Han, Alan M. Haywood, Qiang Li, Xiangyu Li, Gerrit Lohmann, Daniel J. Lunt, Kerim H. Nisancioglu, Bette L. Otto-Bliesner, W. Richard Peltier, Gilles Ramstein, Linda E. Sohl, Christian Stepanek, Ning Tan, Julia C. Tindall, Charles J. R. Williams, Qiong Zhang, and Zhongshi Zhang
Clim. Past, 19, 61–85, https://doi.org/10.5194/cp-19-61-2023, https://doi.org/10.5194/cp-19-61-2023, 2023
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We study the behavior of the Atlantic Meridional Overturning Circulation (AMOC) in the mid-Pliocene. The mid-Pliocene was about 3 million years ago and had a similar CO2 concentration to today. We show that the stronger AMOC during this period relates to changes in geography and that this has a significant influence on ocean temperatures and heat transported northwards by the Atlantic Ocean. Understanding the behavior of the mid-Pliocene AMOC can help us to learn more about our future climate.
Amber Boot, Anna S. von der Heydt, and Henk A. Dijkstra
Earth Syst. Dynam., 13, 1041–1058, https://doi.org/10.5194/esd-13-1041-2022, https://doi.org/10.5194/esd-13-1041-2022, 2022
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Atmospheric pCO2 of the past shows large variability on different timescales. We focus on the effect of the strength of Atlantic Meridional Overturning Circulation (AMOC) on this variability and on the AMOC–pCO2 relationship. We find that climatic boundary conditions and the representation of biology in our model are most important for this relationship. Under certain conditions, we find internal oscillations, which can be relevant for atmospheric pCO2 variability during glacial cycles.
Mikael L. A. Kaandorp, Stefanie L. Ypma, Marijke Boonstra, Henk A. Dijkstra, and Erik van Sebille
Ocean Sci., 18, 269–293, https://doi.org/10.5194/os-18-269-2022, https://doi.org/10.5194/os-18-269-2022, 2022
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A large amount of marine litter, such as plastics, is located on or around beaches. Both the total amount of this litter and its transport are poorly understood. We investigate this by training a machine learning model with data of cleanup efforts on Dutch beaches between 2014 and 2019, obtained by about 14 000 volunteers. We find that Dutch beaches contain up to 30 000 kg of litter, largely depending on tides, oceanic transport, and how exposed the beaches are.
Peter D. Nooteboom, Peter K. Bijl, Christian Kehl, Erik van Sebille, Martin Ziegler, Anna S. von der Heydt, and Henk A. Dijkstra
Earth Syst. Dynam., 13, 357–371, https://doi.org/10.5194/esd-13-357-2022, https://doi.org/10.5194/esd-13-357-2022, 2022
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Having descended through the water column, microplankton in ocean sediments represents the ocean surface environment and is used as an archive of past and present surface oceanographic conditions. However, this microplankton is advected by turbulent ocean currents during its sinking journey. We use simulations of sinking particles to define ocean bottom provinces and detect these provinces in datasets of sedimentary microplankton, which has implications for palaeoclimate reconstructions.
Arthur M. Oldeman, Michiel L. J. Baatsen, Anna S. von der Heydt, Henk A. Dijkstra, Julia C. Tindall, Ayako Abe-Ouchi, Alice R. Booth, Esther C. Brady, Wing-Le Chan, Deepak Chandan, Mark A. Chandler, Camille Contoux, Ran Feng, Chuncheng Guo, Alan M. Haywood, Stephen J. Hunter, Youichi Kamae, Qiang Li, Xiangyu Li, Gerrit Lohmann, Daniel J. Lunt, Kerim H. Nisancioglu, Bette L. Otto-Bliesner, W. Richard Peltier, Gabriel M. Pontes, Gilles Ramstein, Linda E. Sohl, Christian Stepanek, Ning Tan, Qiong Zhang, Zhongshi Zhang, Ilana Wainer, and Charles J. R. Williams
Clim. Past, 17, 2427–2450, https://doi.org/10.5194/cp-17-2427-2021, https://doi.org/10.5194/cp-17-2427-2021, 2021
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In this work, we have studied the behaviour of El Niño events in the mid-Pliocene, a period of around 3 million years ago, using a collection of 17 climate models. It is an interesting period to study, as it saw similar atmospheric carbon dioxide levels to the present day. We find that the El Niño events were less strong in the mid-Pliocene simulations, when compared to pre-industrial climate. Our results could help to interpret El Niño behaviour in future climate projections.
André Jüling, Anna von der Heydt, and Henk A. Dijkstra
Ocean Sci., 17, 1251–1271, https://doi.org/10.5194/os-17-1251-2021, https://doi.org/10.5194/os-17-1251-2021, 2021
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On top of forced changes such as human-caused global warming, unforced climate variability exists. Most multidecadal variability (MV) involves the oceans, but current climate models use non-turbulent, coarse-resolution oceans. We investigate the effect of resolving important turbulent ocean features on MV. We find that ocean heat content, ocean–atmosphere heat flux, and global mean surface temperature MV is more pronounced in the higher-resolution model relative to higher-frequency variability.
Johannes Lohmann, Daniele Castellana, Peter D. Ditlevsen, and Henk A. Dijkstra
Earth Syst. Dynam., 12, 819–835, https://doi.org/10.5194/esd-12-819-2021, https://doi.org/10.5194/esd-12-819-2021, 2021
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Tipping of one climate subsystem could trigger a cascade of subsequent tipping points and even global-scale climate tipping. Sequential shifts of atmosphere, sea ice and ocean have been recorded in proxy archives of past climate change. Based on this we propose a conceptual model for abrupt climate changes of the last glacial. Here, rate-induced tipping enables tipping cascades in systems with relatively weak coupling. An early warning signal is proposed that may detect such a tipping.
André Jüling, Xun Zhang, Daniele Castellana, Anna S. von der Heydt, and Henk A. Dijkstra
Ocean Sci., 17, 729–754, https://doi.org/10.5194/os-17-729-2021, https://doi.org/10.5194/os-17-729-2021, 2021
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We investigate how the freshwater budget of the Atlantic changes under climate change, which has implications for the stability of the Atlantic Meridional Overturning Circulation. We compare the effect of ocean model resolution in a climate model and find many similarities between the simulations, enhancing trust in the current generation of climate models. However, ocean biases are reduced in the strongly eddying simulation, and significant local freshwater budget differences exist.
Pascal Wang, Daniele Castellana, and Henk A. Dijkstra
Nonlin. Processes Geophys., 28, 135–151, https://doi.org/10.5194/npg-28-135-2021, https://doi.org/10.5194/npg-28-135-2021, 2021
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This paper proposes two improvements to the use of Trajectory-Adaptive Multilevel Sampling, a rare-event algorithm which computes noise-induced transition probabilities. The first improvement uses locally linearised dynamics in order to reduce the arbitrariness associated with defining what constitutes a transition. The second improvement uses empirical transition paths accumulated at high noise in order to formulate the score function which determines the performance of the algorithm.
Amber Boot, René M. van Westen, and Henk A. Dijkstra
Ocean Sci., 17, 335–350, https://doi.org/10.5194/os-17-335-2021, https://doi.org/10.5194/os-17-335-2021, 2021
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The Maud Rise polynya is a hole in the sea ice surrounding Antarctica that occurs during winter. It appeared in 2016 and 2017. Our study concludes that heat and salt accumulation around 1000 m depth are likely to be important for polynya formation. The heat is mixed upward to the surface where it is able to melt the sea ice and, thus, create a polynya. How often the polynya forms depends largely on the variation in the time of the heat and salt accumulation.
David Wichmann, Christian Kehl, Henk A. Dijkstra, and Erik van Sebille
Nonlin. Processes Geophys., 28, 43–59, https://doi.org/10.5194/npg-28-43-2021, https://doi.org/10.5194/npg-28-43-2021, 2021
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Fluid parcels transported in complicated flows often contain subsets of particles that stay close over finite time intervals. We propose a new method for detecting finite-time coherent sets based on the density-based clustering technique of ordering points to identify the clustering structure (OPTICS). Unlike previous methods, our method has an intrinsic notion of coherent sets at different spatial scales. OPTICS is readily implemented in the SciPy sklearn package, making it easy to use.
Carine G. van der Boog, J. Otto Koetsier, Henk A. Dijkstra, Julie D. Pietrzak, and Caroline A. Katsman
Earth Syst. Sci. Data, 13, 43–61, https://doi.org/10.5194/essd-13-43-2021, https://doi.org/10.5194/essd-13-43-2021, 2021
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Thermohaline staircases are stepped structures in the ocean that contain enhanced diapycnal salt and heat transport. In this study, we present a global dataset of thermohaline staircases derived from 487 493 observations of Argo profiling floats and Ice-Tethered Profilers using a novel detection algorithm.
Michiel Baatsen, Anna S. von der Heydt, Matthew Huber, Michael A. Kliphuis, Peter K. Bijl, Appy Sluijs, and Henk A. Dijkstra
Clim. Past, 16, 2573–2597, https://doi.org/10.5194/cp-16-2573-2020, https://doi.org/10.5194/cp-16-2573-2020, 2020
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Warm climates of the deep past have proven to be challenging to reconstruct with the same numerical models used for future predictions. We present results of CESM simulations for the middle to late Eocene (∼ 38 Ma), in which we managed to match the available indications of temperature well. With these results we can now look into regional features and the response to external changes to ultimately better understand the climate when it is in such a warm state.
René M. van Westen and Henk A. Dijkstra
Ocean Sci., 16, 1443–1457, https://doi.org/10.5194/os-16-1443-2020, https://doi.org/10.5194/os-16-1443-2020, 2020
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During the mid-1970s and quite recently in 2017, a large open-water area appeared in the Antarctic sea-ice pack, the so-called Maud Rise polynya. From several model studies, the reoccurrence time of this polynya seems arbitrary. In this study, we address the reoccurrence time of the polynya using a high-resolution climate model. We find a preferred multidecadal return time in polynya formation. The return time of the polynya is associated with a large-scale ocean mode in the Southern Ocean.
David Wichmann, Christian Kehl, Henk A. Dijkstra, and Erik van Sebille
Nonlin. Processes Geophys., 27, 501–518, https://doi.org/10.5194/npg-27-501-2020, https://doi.org/10.5194/npg-27-501-2020, 2020
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The surface transport of heat, nutrients and plastic in the North Atlantic Ocean is organized into large-scale flow structures. We propose a new and simple method to detect such features in ocean drifter data sets by identifying groups of trajectories with similar dynamical behaviour using network theory. We successfully detect well-known regions such as the Subpolar and Subtropical gyres, the Western Boundary Current region and the Caribbean Sea.
Giovanni Coco, Daniel Calvete, Francesca Ribas, Huib E. de Swart, and Albert Falqués
Earth Surf. Dynam., 8, 323–334, https://doi.org/10.5194/esurf-8-323-2020, https://doi.org/10.5194/esurf-8-323-2020, 2020
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Sandbars are ubiquitous features of the surf zone. They are rarely straight and often develop crescentic shapes. Double sandbar systems are also common, but the possibility of feedback between inner and outer sandbars has not been fully explored. The presence of double sandbar systems affects wave transformation and can result in a variety of spatial patterns. Here we model the conditions, waves and initial bathymetry that lead to the emergence of different patterns.
René M. van Westen and Henk A. Dijkstra
Ocean Sci. Discuss., https://doi.org/10.5194/os-2020-33, https://doi.org/10.5194/os-2020-33, 2020
Revised manuscript not accepted
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In 2016 and 2017, an open-water area emerged within the Antarctic sea-ice pack, the so-called Maud Rise polynya. The opening of the sea ice has been linked to intense winter storms. In this study, we investigate another important contributor to polynya formation by analysing subsurface static instabilities. These static instabilities initiate subsurface convection near Maud Rise. We conclude that apart from winter storms, subsurface convection plays an important role in polynya formation.
Ann Kristin Klose, René M. van Westen, and Henk A. Dijkstra
Ocean Sci., 16, 435–449, https://doi.org/10.5194/os-16-435-2020, https://doi.org/10.5194/os-16-435-2020, 2020
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We give an explanation of the decadal timescale path variations in the Kuroshio Current in the North Pacific based on highly detailed climate
model simulations.
Carine G. van der Boog, Julie D. Pietrzak, Henk A. Dijkstra, Nils Brüggemann, René M. van Westen, Rebecca K. James, Tjeerd J. Bouma, Riccardo E. M. Riva, D. Cornelis Slobbe, Roland Klees, Marcel Zijlema, and Caroline A. Katsman
Ocean Sci., 15, 1419–1437, https://doi.org/10.5194/os-15-1419-2019, https://doi.org/10.5194/os-15-1419-2019, 2019
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We use a model of the Caribbean Sea to study how coastal upwelling along Venezuela impacts the evolution of energetic anticyclonic eddies. We show that the anticyclones grow by the advection of the cold upwelling filaments. These filaments increase the density gradient and vertical shear of the anticyclones. Furthermore, we show that stronger upwelling results in stronger eddies, while model simulations with weaker upwelling contain weaker eddies.
Henk A. Dijkstra
Nonlin. Processes Geophys., 26, 359–369, https://doi.org/10.5194/npg-26-359-2019, https://doi.org/10.5194/npg-26-359-2019, 2019
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I provide a personal view on the role of bifurcation analysis of climate models in the development of a theory of variability in the climate system. By outlining the state of the art of the methodology and by discussing what has been done and what has been learned from a hierarchy of models, I will argue that there are low-order phenomena of climate variability, such as El Niño and the Atlantic Multidecadal Oscillation.
Juan-Manuel Sayol, Henk Dijkstra, and Caroline Katsman
Ocean Sci., 15, 1033–1053, https://doi.org/10.5194/os-15-1033-2019, https://doi.org/10.5194/os-15-1033-2019, 2019
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This work uses high-resolution ocean model data to quantify the sinking of waters in the subpolar North Atlantic. The largest amount of sinking is found at the depth of maximum AMOC at 45° N below the mixed layer depth, and 90 % of the sinking occurs near the boundaries in the first 250 km off the shelf. The characteristics of the sinking (total amount, seasonal variability, and vertical structure) vary largely according to the region considered, revealing a complex picture for the sinking.
Koen G. Helwegen, Claudia E. Wieners, Jason E. Frank, and Henk A. Dijkstra
Earth Syst. Dynam., 10, 453–472, https://doi.org/10.5194/esd-10-453-2019, https://doi.org/10.5194/esd-10-453-2019, 2019
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We use the climate-economy model DICE to perform a cost–benefit analysis of sulfate geoengineering, i.e. producing a thin artificial sulfate haze in the higher atmosphere to reflect some sunlight and cool the Earth.
We find that geoengineering can increase future welfare by reducing global warming, and should be taken seriously as a policy option, but it can only complement, not replace, carbon emission reduction. The best policy is to combine CO2 emission reduction with modest geoengineering.
Martijn Westhoff, Axel Kleidon, Stan Schymanski, Benjamin Dewals, Femke Nijsse, Maik Renner, Henk Dijkstra, Hisashi Ozawa, Hubert Savenije, Han Dolman, Antoon Meesters, and Erwin Zehe
Earth Syst. Dynam. Discuss., https://doi.org/10.5194/esd-2019-6, https://doi.org/10.5194/esd-2019-6, 2019
Publication in ESD not foreseen
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Even models relying on physical laws have parameters that need to be measured or estimated. Thermodynamic optimality principles potentially offer a way to reduce the number of estimated parameters by stating that a system evolves to an optimum state. These principles have been applied successfully within the Earth system, but it is often unclear what to optimize and how. In this review paper we identify commonalities between different successful applications as well as some doubtful applications.
Mark M. Dekker, Anna S. von der Heydt, and Henk A. Dijkstra
Earth Syst. Dynam., 9, 1243–1260, https://doi.org/10.5194/esd-9-1243-2018, https://doi.org/10.5194/esd-9-1243-2018, 2018
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We introduce a framework of cascading tipping, i.e. a sequence of abrupt transitions occurring because a transition in one system affects the background conditions of another system. Using bifurcation theory, various types of these events are considered and early warning indicators are suggested. An illustration of such an event is found in a conceptual model, coupling the North Atlantic Ocean with the equatorial Pacific. This demonstrates the possibility of events such as this in nature.
Matthias Aengenheyster, Qing Yi Feng, Frederick van der Ploeg, and Henk A. Dijkstra
Earth Syst. Dynam., 9, 1085–1095, https://doi.org/10.5194/esd-9-1085-2018, https://doi.org/10.5194/esd-9-1085-2018, 2018
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We determine the point of no return (PNR) for climate change, which is the latest year to take action to reduce greenhouse gases to stay, with a certain probability, within thresholds set by the Paris Agreement. For a 67 % probability and a 2 K threshold, the PNR is the year 2035 when the share of renewable energy rises by 2 % per year. We show the impact on the PNR of the speed by which emissions are cut, the risk tolerance, climate uncertainties and the potential for negative emissions.
Femke J. M. M. Nijsse and Henk A. Dijkstra
Earth Syst. Dynam., 9, 999–1012, https://doi.org/10.5194/esd-9-999-2018, https://doi.org/10.5194/esd-9-999-2018, 2018
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State-of-the-art climate models sometimes differ in their prediction of key aspects of climate change. The technique of
emergent constraintsuses observations of current climate to improve those predictions, using relationships between different climate models. Our paper first classifies the different uses of the technique, and continues with proposing a mathematical justification for their use. We also highlight when the application of emergent constraints might give biased predictions.
Peter D. Nooteboom, Qing Yi Feng, Cristóbal López, Emilio Hernández-García, and Henk A. Dijkstra
Earth Syst. Dynam., 9, 969–983, https://doi.org/10.5194/esd-9-969-2018, https://doi.org/10.5194/esd-9-969-2018, 2018
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The prediction of the El Niño phenomenon, an increased sea surface temperature in the eastern Pacific, fascinates people for a long time. El Niño is associated with natural disasters, such as droughts and floods. Current methods can make a reliable prediction of this phenomenon up to 6 months ahead. However, this article presents a method which combines network theory and machine learning which predicts El Niño up to 1 year ahead.
Michiel Baatsen, Anna S. von der Heydt, Matthew Huber, Michael A. Kliphuis, Peter K. Bijl, Appy Sluijs, and Henk A. Dijkstra
Clim. Past Discuss., https://doi.org/10.5194/cp-2018-43, https://doi.org/10.5194/cp-2018-43, 2018
Revised manuscript not accepted
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The Eocene marks a period where the climate was in a hothouse state, without any continental-scale ice sheets. Such climates have proven difficult to reproduce in models, especially their low temperature difference between equator and poles. Here, we present high resolution CESM simulations using a new geographic reconstruction of the middle-to-late Eocene. The results provide new insights into a period for which knowledge is limited, leading up to a transition into the present icehouse state.
Inti Pelupessy, Ben van Werkhoven, Arjen van Elteren, Jan Viebahn, Adam Candy, Simon Portegies Zwart, and Henk Dijkstra
Geosci. Model Dev., 10, 3167–3187, https://doi.org/10.5194/gmd-10-3167-2017, https://doi.org/10.5194/gmd-10-3167-2017, 2017
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Researchers from the Netherlands present OMUSE, a software package
developed from core technology originating in the astrophysical
community. Using OMUSE, oceanographic and climate researchers can
develop numerical models of the ocean and the interactions between
different parts of the ocean and the atmosphere. This provides a novel
way to investigate, for example, the local effects of climate change on
the ocean. OMUSE is freely available as open-source software.
Brenda C. van Zalinge, Qing Yi Feng, Matthias Aengenheyster, and Henk A. Dijkstra
Earth Syst. Dynam., 8, 707–717, https://doi.org/10.5194/esd-8-707-2017, https://doi.org/10.5194/esd-8-707-2017, 2017
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The increase in atmospheric greenhouse gases (GHGs) is one of the main causes for the increase in global mean surface temperature. There is no good quantitative measure to determine when it is
too lateto start reducing GHGs in order to avoid dangerous anthropogenic interference. We develop a method for determining a so-called point of no return (PNR) for several GHG emission scenarios. The innovative element in this approach is the applicability to high-dimensional climate models.
Daniel J. Lunt, Matthew Huber, Eleni Anagnostou, Michiel L. J. Baatsen, Rodrigo Caballero, Rob DeConto, Henk A. Dijkstra, Yannick Donnadieu, David Evans, Ran Feng, Gavin L. Foster, Ed Gasson, Anna S. von der Heydt, Chris J. Hollis, Gordon N. Inglis, Stephen M. Jones, Jeff Kiehl, Sandy Kirtland Turner, Robert L. Korty, Reinhardt Kozdon, Srinath Krishnan, Jean-Baptiste Ladant, Petra Langebroek, Caroline H. Lear, Allegra N. LeGrande, Kate Littler, Paul Markwick, Bette Otto-Bliesner, Paul Pearson, Christopher J. Poulsen, Ulrich Salzmann, Christine Shields, Kathryn Snell, Michael Stärz, James Super, Clay Tabor, Jessica E. Tierney, Gregory J. L. Tourte, Aradhna Tripati, Garland R. Upchurch, Bridget S. Wade, Scott L. Wing, Arne M. E. Winguth, Nicky M. Wright, James C. Zachos, and Richard E. Zeebe
Geosci. Model Dev., 10, 889–901, https://doi.org/10.5194/gmd-10-889-2017, https://doi.org/10.5194/gmd-10-889-2017, 2017
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In this paper we describe the experimental design for a set of simulations which will be carried out by a range of climate models, all investigating the climate of the Eocene, about 50 million years ago. The intercomparison of model results is called 'DeepMIP', and we anticipate that we will contribute to the next IPCC report through an analysis of these simulations and the geological data to which we will compare them.
S.-E. Brunnabend, H. A. Dijkstra, M. A. Kliphuis, H. E. Bal, F. Seinstra, B. van Werkhoven, J. Maassen, and M. van Meersbergen
Ocean Sci., 13, 47–60, https://doi.org/10.5194/os-13-47-2017, https://doi.org/10.5194/os-13-47-2017, 2017
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An important contribution to future changes in regional sea level extremes is due to the changes in intrinsic ocean variability, in particular ocean eddies. Here, we study a scenario of future dynamic sea level (DSL) extremes using a strongly eddying version of the Parallel Ocean Program. Changes in 10-year return time DSL extremes are very inhomogeneous over the globe and are related to changes in ocean currents and corresponding regional shifts in ocean eddy pathways.
Michiel Baatsen, Douwe J. J. van Hinsbergen, Anna S. von der Heydt, Henk A. Dijkstra, Appy Sluijs, Hemmo A. Abels, and Peter K. Bijl
Clim. Past, 12, 1635–1644, https://doi.org/10.5194/cp-12-1635-2016, https://doi.org/10.5194/cp-12-1635-2016, 2016
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One of the major difficulties in modelling palaeoclimate is constricting the boundary conditions, causing significant discrepancies between different studies. Here, a new method is presented to automate much of the process of generating the necessary geographical reconstructions. The latter can be made using various rotational frameworks and topography/bathymetry input, allowing for easy inter-comparisons and the incorporation of the latest insights from geoscientific research.
Zun Yin, Stefan C. Dekker, Bart J. J. M. van den Hurk, and Henk A. Dijkstra
Biogeosciences, 13, 3343–3357, https://doi.org/10.5194/bg-13-3343-2016, https://doi.org/10.5194/bg-13-3343-2016, 2016
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Bimodality is found in aboveground biomass and mean annual shortwave radiation in West Africa, which is a strong evidence of alternative stable states. The condition with low biomass and low radiation is demonstrated under which ecosystem state can shift between savanna and forest states. Moreover, climatic indicators have different prediction confidences to different land cover types. A new method is proposed to predict potential land cover change with a combination of climatic indicators.
Qing Yi Feng, Ruggero Vasile, Marc Segond, Avi Gozolchiani, Yang Wang, Markus Abel, Shilomo Havlin, Armin Bunde, and Henk A. Dijkstra
Geosci. Model Dev. Discuss., https://doi.org/10.5194/gmd-2015-273, https://doi.org/10.5194/gmd-2015-273, 2016
Revised manuscript not accepted
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We present the toolbox ClimateLearn to tackle problems in climate prediction using machine learning techniques and climate network analysis. Because spatial temporal information on climate variability can be efficiently represented by complex network measures, such data are considered here as input to the machine-learning algorithms. As an example, the toolbox is applied to the prediction of the occurrence and the development of El Niño in the equatorial Pacific.
H. Ihshaish, A. Tantet, J. C. M. Dijkzeul, and H. A. Dijkstra
Geosci. Model Dev., 8, 3321–3331, https://doi.org/10.5194/gmd-8-3321-2015, https://doi.org/10.5194/gmd-8-3321-2015, 2015
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Par@Graph, a software toolbox to reconstruct and analyze large-scale complex climate networks. It exposes parallelism on distributed-memory computing platforms to enable the construction of massive networks from large number of time series based on the calculation of common statistical similarity measures between them. Providing additionally parallel graph algorithms to enable fast calculation of important and common properties of the generated networks on SMP machines.
L. Hahn-Woernle, H. A. Dijkstra, and H. J. Van der Woerd
Ocean Sci., 10, 993–1011, https://doi.org/10.5194/os-10-993-2014, https://doi.org/10.5194/os-10-993-2014, 2014
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Measured vertical mixing profiles are applied to a 1-D phytoplankton model. Results show that shifts in vertical mixing are able to induce a transition from an upper chlorophyll maximum to a deep one and vice versa. Furthermore, a clear correlation between the surface phytoplankton concentration and mixing-induced nutrient flux is found for nutrient-limited cases. This result suggests that characteristics of the vertical mixing could be determined from the surface phytoplankton concentration.
S.-E. Brunnabend, H. A. Dijkstra, M. A. Kliphuis, B. van Werkhoven, H. E. Bal, F. Seinstra, J. Maassen, and M. van Meersbergen
Ocean Sci., 10, 881–891, https://doi.org/10.5194/os-10-881-2014, https://doi.org/10.5194/os-10-881-2014, 2014
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Regional sea surface height (SSH) changes due to an abrupt weakening of the Atlantic meridional overturning circulation (AMOC) are simulated with a high- and low-resolution model. A rapid decrease of the AMOC in the high-resolution version induces shorter return times of several specific regional and coastal extremes in North Atlantic SSH than in the low-resolution version. This effect is caused by a change in main eddy pathways associated with a change in separation latitude of the Gulf Stream.
Z. Yin, S. C. Dekker, B. J. J. M. van den Hurk, and H. A. Dijkstra
Earth Syst. Dynam., 5, 257–270, https://doi.org/10.5194/esd-5-257-2014, https://doi.org/10.5194/esd-5-257-2014, 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
Z. Yin, S. C. Dekker, B. J. J. M. van den Hurk, and H. A. Dijkstra
Geosci. Model Dev., 7, 821–845, https://doi.org/10.5194/gmd-7-821-2014, https://doi.org/10.5194/gmd-7-821-2014, 2014
G. Sgubin, S. Pierini, and H. A. Dijkstra
Ocean Sci., 10, 201–213, https://doi.org/10.5194/os-10-201-2014, https://doi.org/10.5194/os-10-201-2014, 2014
A. Tantet and H. A. Dijkstra
Earth Syst. Dynam., 5, 1–14, https://doi.org/10.5194/esd-5-1-2014, https://doi.org/10.5194/esd-5-1-2014, 2014
A. A. Cimatoribus, S. Drijfhout, and H. A. Dijkstra
Ocean Sci. Discuss., https://doi.org/10.5194/osd-10-2461-2013, https://doi.org/10.5194/osd-10-2461-2013, 2013
Preprint withdrawn
A. S. von der Heydt, A. Nnafie, and H. A. Dijkstra
Clim. Past, 7, 903–915, https://doi.org/10.5194/cp-7-903-2011, https://doi.org/10.5194/cp-7-903-2011, 2011
M. Tigchelaar, A. S. von der Heydt, and H. A. Dijkstra
Clim. Past, 7, 235–247, https://doi.org/10.5194/cp-7-235-2011, https://doi.org/10.5194/cp-7-235-2011, 2011
J. O. Sewall, R. S. W. van de Wal, K. van der Zwan, C. van Oosterhout, H. A. Dijkstra, and C. R. Scotese
Clim. Past, 3, 647–657, https://doi.org/10.5194/cp-3-647-2007, https://doi.org/10.5194/cp-3-647-2007, 2007
Related subject area
Approach: Numerical Models | Properties and processes: Coastal and near-shore processes
Influence of river runoff and precipitation on the seasonal and interannual variability of sea surface salinity in the eastern North Tropical Atlantic
A three-quantile bias correction with spatial transfer for the correction of simulated European river runoff to force ocean models
River discharge impacts coastal Southeastern Tropical Atlantic sea surface temperature and circulation: a model-based analysis
High-resolution numerical modelling of seasonal volume, freshwater, and heat transport along the Indian coast
Alongshore sediment transport analysis for a semi-enclosed basin: a case study of the Gulf of Riga, the Baltic Sea
Mechanisms and intraseasonal variability in the South Vietnam Upwelling, South China Sea: the role of circulation, tides, and rivers
Anthropogenic pressures driving the salinity intrusion in the Guadalquivir Estuary: Insights from 1D Numerical Simulations
The influence of a submarine canyon on the wind-driven downwelling circulation over the continental shelf
Application of Wave-current coupled Sediment Transport Models with Variable Grain Properties for Coastal Morphodynamics: A Case Study of the Changhua River, Hainan
Exploring water accumulation dynamics in the Pearl River estuary from a Lagrangian perspective
Exploring the tidal response to bathymetry evolution and present-day sea level rise in a channel–shoal environment
Wave-resolving Voronoi model of Rouse number for sediment entrainment equilibrium
Influence of stratification and wind forcing on the dynamics of Lagrangian residual velocity in a periodically stratified estuary
Fjord circulation permits a persistent subsurface water mass in a long, deep mid-latitude inlet
Salt intrusion dynamics in a well-mixed sub-estuary connected to a partially to well-mixed main estuary
Transport dynamics in a complex coastal archipelago
Modeling the interannual variability in Maipo and Rapel river plumes off central Chile
Short-term prediction of the significant wave height and average wave period based on the variational mode decomposition–temporal convolutional network–long short-term memory (VMD–TCN–LSTM) algorithm
Clovis Thouvenin-Masson, Jacqueline Boutin, Vincent Échevin, Alban Lazar, and Jean-Luc Vergely
Ocean Sci., 20, 1547–1566, https://doi.org/10.5194/os-20-1547-2024, https://doi.org/10.5194/os-20-1547-2024, 2024
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We focus on understanding the impact of river runoff and precipitation on sea surface salinity (SSS) in the eastern North Tropical Atlantic (e-NTA) region off northwestern Africa. By analyzing regional simulations and observational data, we find that river flows significantly influence SSS variability, particularly after the rainy season. Our findings underscore that a main source of uncertainty representing SSS variability in this region is from river runoff estimates.
Stefan Hagemann, Thao Thi Nguyen, and Ha Thi Minh Ho-Hagemann
Ocean Sci., 20, 1457–1478, https://doi.org/10.5194/os-20-1457-2024, https://doi.org/10.5194/os-20-1457-2024, 2024
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We have developed a methodology for the bias correction of simulated river runoff to force ocean models in which low, medium, and high discharges are corrected once separated at the coast. We show that the bias correction generally leads to an improved representation of river runoff in Europe. The methodology is suitable for model regions with a sufficiently high coverage of discharge observations, and it can be applied to river runoff based on climate hindcasts or climate change simulations.
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
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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.
Kunal Madkaiker, Ambarukhana D. Rao, and Sudheer Joseph
Ocean Sci., 20, 1167–1185, https://doi.org/10.5194/os-20-1167-2024, https://doi.org/10.5194/os-20-1167-2024, 2024
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Using a high-resolution model, we estimated the volume, freshwater, and heat transports along Indian coasts. Affected by coastal currents, transport along the eastern coast is highly seasonal, and the western coast is impacted by intraseasonal oscillations. Coastal currents and equatorial forcing determine the relation between NHT and net heat flux in dissipating heat in coastal waters. The north Indian Ocean functions as a heat source or sink based on seasonal flow of meridional heat transport.
Tarmo Soomere, Mikolaj Zbiegniew Jankowski, Maris Eelsalu, Kevin Ellis Parnell, and Maija Viška
EGUsphere, https://doi.org/10.5194/egusphere-2024-2640, https://doi.org/10.5194/egusphere-2024-2640, 2024
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Seemingly interconnected beaches are often separated by man-made obstacles and natural divergence areas of sediment flux. We decompose the sedimentary shores of the Gulf of Riga into five naturally almost isolated compartments based on the analysis of wave-driven sediment flux. The western, southern and eastern shores have quite different and fragmented sediment transport regimes. The transport rates along different shore segments show extensive interannual variations but no explicit trends.
Marine Herrmann, Thai To Duy, and Patrick Marsaleix
Ocean Sci., 20, 1013–1033, https://doi.org/10.5194/os-20-1013-2024, https://doi.org/10.5194/os-20-1013-2024, 2024
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In summer, deep, cold waters rise to the surface along and off the Vietnamese coast. This upwelling of water lifts nutrients, inducing biological activity that is important for fishery resources. Strong tides occur on the shelf off the Mekong Delta. By increasing the mixing of ocean waters and modifying currents, they are a major factor in the development of upwelling on the shelf, accounting for ~75 % of its average summer intensity.
Sara Sirviente, Juan Jesús Gomiz-Pascual, Marina Bolado-Penagos, Sabine Sauvage, José Miguel Sánchez-Pérez, and Miguel Bruno
EGUsphere, https://doi.org/10.5194/egusphere-2024-2451, https://doi.org/10.5194/egusphere-2024-2451, 2024
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The study analyzes how anthropogenic pressures affect saltwater intrusion in the Guadalquivir estuary using a 1D hydrodynamic model. Water extraction by human activities has caused excessive intrusion of the salt wedge, altering the natural state of the system. A better understanding of the effects of these activities is essential to protect the ecosystems of the estuary.
Pedro Figueroa, Gonzalo Saldías, and Susan Allen
EGUsphere, https://doi.org/10.5194/egusphere-2024-2386, https://doi.org/10.5194/egusphere-2024-2386, 2024
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Submarine canyons are topographic features found along the continental slope worldwide. Here we use numerical simulations to study how a submarine canyon influences the circulation near the coast when winds moving poleward influence the region. Our results show that submarine canyons modify the circulation near the coast, causing strong velocities perpendicular to the coast. These changes can trap particles inside the canyon, an important mechanism to explain its role as a biological hotspot.
Yuxi Wu, Enjin Zhao, Xiwen Li, and Shiyou Zhang
EGUsphere, https://doi.org/10.5194/egusphere-2024-2154, https://doi.org/10.5194/egusphere-2024-2154, 2024
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This study presents a comprehensive sand transport model to investigate sediment dynamics in the downstream Changhua River estuary of Hainan Island. It captures the intricate relationship between wave action, currents, and sediment transport. Verified against field measurements, the model exposes notable sediment deposition, significantly affected by coastal currents and geological structures. These insights provide strategies for sedimentation monitoring and control.
Mingyu Li, Alessandro Stocchino, Zhongya Cai, and Tingting Zu
Ocean Sci., 20, 931–944, https://doi.org/10.5194/os-20-931-2024, https://doi.org/10.5194/os-20-931-2024, 2024
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In this study, we explored how water accumulates in a coastal estuary, a key factor affecting the estuary's environmental health and ecosystem. We revealed significant bottom accumulations influenced by plume fronts and velocity convergence, with notable seasonal variability. By analyzing trajectories, we identified subregions with distinct accumulation patterns and examined their interconnections, highlighting the substantial impact of tides and river discharge on these dynamics.
Robert Lepper, Leon Jänicke, Ingo Hache, Christian Jordan, and Frank Kösters
Ocean Sci., 20, 711–723, https://doi.org/10.5194/os-20-711-2024, https://doi.org/10.5194/os-20-711-2024, 2024
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Most coastal environments are sheltered by tidal flats and salt marshes. These habitats are threatened from drowning under sea level rise. Contrary to expectation, recent analyses in the Wadden Sea showed that tidal flats can accrete faster than sea level rise. We found that this phenomenon was facilitated by the nonlinear link between tidal characteristics and coastal bathymetry evolution. This link caused local and regional tidal adaptation with sharp increase–decrease edges at the coast.
Johannes Lawen
EGUsphere, https://doi.org/https://doi.org/10.48550/arXiv.2404.10878, https://doi.org/https://doi.org/10.48550/arXiv.2404.10878, 2024
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A new Voronoi mesh-borne coastal ocean model has been developed. Recent publications encouraged the development of models that work with different mesh types. Voronoi meshes exhibit less acute polygon angles and less numerical diffusion. The developed model is sufficiently generalized to work with any mesh type (Delaunay triangles, Voronoi, structured, mixed). The model is suitable for wave-resolving simulations for coastal developments to resolve intricate changes in erosion and deposition.
Fangjing Deng, Feiyu Jia, Rui Shi, Shuwen Zhang, Qiang Lian, Xiaolong Zong, and Zhaoyun Chen
Ocean Sci., 20, 499–519, https://doi.org/10.5194/os-20-499-2024, https://doi.org/10.5194/os-20-499-2024, 2024
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Southwesterly winds impact cross-estuary flows by amplifying the eddy viscosity component during smaller tides. Moreover, they modify along-estuary gravitational circulation by diminishing both the barotropic and baroclinic components. Stratification results in contrasting sheared flows, distinguished by different dominant components compared to destratified conditions. Additionally, the eddy viscosity component is governed by various subcomponents in diverse stratified waters.
Laura Bianucci, Jennifer M. Jackson, Susan E. Allen, Maxim V. Krassovski, Ian J. W. Giesbrecht, and Wendy C. Callendar
Ocean Sci., 20, 293–306, https://doi.org/10.5194/os-20-293-2024, https://doi.org/10.5194/os-20-293-2024, 2024
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While the deeper waters in the coastal ocean show signs of climate-change-induced warming and deoxygenation, some fjords can keep cool and oxygenated waters in the subsurface. We use a model to investigate how these subsurface waters created during winter can linger all summer in Bute Inlet, Canada. We found two main mechanisms that make this fjord retentive: the typical slow subsurface circulation in such a deep, long fjord and the further speed reduction when the cold waters are present.
Zhongyuan Lin, Guang Zhang, Huazhi Zou, and Wenping Gong
Ocean Sci., 20, 181–199, https://doi.org/10.5194/os-20-181-2024, https://doi.org/10.5194/os-20-181-2024, 2024
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From 2021 to 2022, a particular sub-estuary (East River estuary) suffered greatly from an enhanced salt intrusion. We conducted observation analysis, numerical simulations, and analytical solution to unravel the underlying mechanisms. This study is of help in the investigation of salt dynamics in sub-estuaries connected to main estuaries and of implications for mitigating salt intrusion problems in the regions.
Elina Miettunen, Laura Tuomi, Antti Westerlund, Hedi Kanarik, and Kai Myrberg
Ocean Sci., 20, 69–83, https://doi.org/10.5194/os-20-69-2024, https://doi.org/10.5194/os-20-69-2024, 2024
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We studied circulation and transports in the Archipelago Sea (in the Baltic Sea) with a high-resolution hydrodynamic model. Transport dynamics show different variabilities in the north and south, so no single transect can represent transport through the whole area in all cases. The net transport in the surface layer is southward and follows the alignment of the deeper channels. In the lower layer, the net transport is southward in the northern part of the area and northward in the southern part.
Julio Salcedo-Castro, Antonio Olita, Freddy Saavedra, Gonzalo S. Saldías, Raúl C. Cruz-Gómez, and Cristian D. De la Torre Martínez
Ocean Sci., 19, 1687–1703, https://doi.org/10.5194/os-19-1687-2023, https://doi.org/10.5194/os-19-1687-2023, 2023
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Considering the relevance and impact of river discharges on the coastal environment, it is necessary to understand the processes associated with river plume dynamics in different regions and at different scales. Modeling studies focused on the eastern Pacific coast under the influence of the Humboldt Current are scarce. Here, we conduct for the first time an interannual modeling study of two river plumes off central Chile and discuss their characteristics.
Qiyan Ji, Lei Han, Lifang Jiang, Yuting Zhang, Minghong Xie, and Yu Liu
Ocean Sci., 19, 1561–1578, https://doi.org/10.5194/os-19-1561-2023, https://doi.org/10.5194/os-19-1561-2023, 2023
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Accurate wave forecasts are essential to marine engineering safety. The research designs a model with combined signal decomposition and multiple neural network algorithms to predict wave parameters. The hybrid wave prediction model has good robustness and generalization ability. The contribution of the various algorithms to the model prediction skill was analyzed by the ablation experiments. This work provides a neoteric view of marine element forecasting based on artificial intelligence.
Cited articles
Aristizábal, M. F. and Chant, R. J.: An observational study of salt fluxes in Delaware Bay, J. Geophys. Res.-Ocean., 120, 2751–2768, https://doi.org/10.1002/2014JC010680, 2015. a
Banas, N. S., Hickey, B. M., MacCready, P., and Newton, J. A.: Dynamics of Willapa Bay, Washington: A highly unsteady, partially mixed estuary, J. Phys. Oceanogr., 34, 2413–2427, https://doi.org/10.1175/JPO2637.1, 2004. a, b
Bellafiore, D., Ferrarin, C., Maicu, F., Manfè, G., Lorenzetti, G., Umgiesser, G., Zaggia, L., and Levinson, A. V.: Saltwater intrusion in a Mediterranean delta under a changing climate, J. Geophys. Res.-Ocean., 126, e2020JC016437, https://doi.org/10.1029/2020JC016437, 2021. a, b, c
Biemond, B.: Software for “Dynamics of salt intrusion in complex estuarine networks; an idealised model applied to the Rhine-Meuse Delta” (Version 4.3.6), Zenodo [code], https://doi.org/10.5281/zenodo.12793378, 2024. a, b
Biemond, B., de Swart, H. E., Dijkstra, H. A., and Díez-Minguito, M.: Estuarine salinity response to freshwater pulses, J. Geophys. Res.-Ocean., 127, e2022JC018669, https://doi.org/10.1029/2022JC018669, 2022. a
Biemond, B., de Swart, H. E., and Dijkstra, H. A.: Mechanisms of salt overspill at estuarine network junctions explained with an idealized model, J. Geophys. Res.-Ocean., 128, e2023JC019630, https://doi.org/10.1029/2023JC019630, 2023. a
Biemond, B., Vuik, V., Lambregts, P., de Swart, H. E., and Dijkstra, H. A.: Salt intrusion and effective longitudinal dispersion in man-made canals, a simplified model approach, Estuar. Coast. Shelf Sci., 298, 108654, https://doi.org/10.1016/j.ecss.2024.108654, 2024b. a
Bowen, M. M. and Geyer, W. R.: Salt transport and the time-dependent salt balance of a partially stratified estuary, J. Geophys. Res.-Ocean., 108, 3158, https://doi.org/10.1029/2001JC001231, 2003. a
Bricheno, L. M., Wolf, J., and Sun, Y.: Saline intrusion in the Ganges-Brahmaputra-Meghna megadelta, Estuar. Coast. Shelf Sci., 252, 107246, https://doi.org/10.1016/j.ecss.2021.107246, 2021. a
Buschman, F. A., Hoitink, A. J. F., van der Vegt, M., and Hoekstra, P.: Subtidal flow division at a shallow tidal junction, Water Resour. Res., 46, W12515, https://doi.org/10.1029/2010WR009266, 2010. a
Chatwin, P.: Some remarks on the maintenance of the salinity distribution in estuaries, Estuar. Coast. Mar. Sci., 4, 555–566, https://doi.org/10.1016/0302-3524(76)90030-X, 1976. a, b
Chen, S.-N.: Asymmetric estuarine responses to changes in river forcing: A consequence of nonlinear salt flux, J. Phys. Oceanogr., 45, 2836–2847, https://doi.org/10.1175/JPO-D-15-0085.1, 2015. a, b
Corlett, W. B. and Geyer, W. R.: Frontogenesis at Estuarine Junctions, Estuar. Coast., 43, 722–738, https://doi.org/10.1007/s12237-020-00697-1, 2020. a
Cox, J. R., Huismans, Y., Knaake, S. M., Leuven, J. R. F. W., Vellinga, N. E., van der Vegt, M., Hoitink, A. J. F., and Kleinhans, M. G.: Anthropogenic Effects on the Contemporary Sediment Budget of the Lower Rhine-Meuse Delta Channel Network, Earth's Future, 9, e2020EF001869, https://doi.org/10.1029/2020EF001869, 2021. a
Davies, A. M. and Jones, J. E.: Sensitivity of Tidal Bed Stress Distributions, Near-Bed Currents, Overtides, and Tidal Residuals to Frictional Effects in the Eastern Irish Sea, J. Phys. Oceanogr., 26, 2553–2575, https://doi.org/10.1175/1520-0485(1996)026<2553:SOTBSD>2.0.CO;2, 1996. a
de Nijs, M. A. and Pietrzak, J. D.: Saltwater intrusion and ETM dynamics in a tidally-energetic stratified estuary, Ocean Model., 49/50, 60–85, https://doi.org/10.1016/j.ocemod.2012.03.004, 2012. a
Dijkstra, Y. M. and Schuttelaars, H. M.: A unifying approach to subtidal salt intrusion modeling in tidal estuaries, J. Phys. Oceanogr., 51, 147–167, https://doi.org/10.1175/JPO-D-20-0006.1, 2021. a
Eckhaus, W.: Asymptotic analysis of singular perturbations, Elsevier, ISBN-10: 0444853065, ISBN-13: 978-0444853066, 2011. a
Eslami, S., Hoekstra, P., Kernkamp, H. W. J., Nguyen Trung, N., Do Duc, D., Nguyen Nghia, H., Tran Quang, T., van Dam, A., Darby, S. E., Parsons, D. R., Vasilopoulos, G., Braat, L., and van der Vegt, M.: Dynamics of salt intrusion in the Mekong Delta: results of field observations and integrated coastal–inland modelling, Earth Surf. Dynam., 9, 953–976, https://doi.org/10.5194/esurf-9-953-2021, 2021. a
Garcia, A. M. P., Geyer, W. R., and Randall, N.: Exchange Flows in Tributary Creeks Enhance Dispersion by Tidal Trapping, Estuar. Coast., 45, 363–381, https://doi.org/10.1007/s12237-021-00969-4, 2022. a
Geyer, W. R. and MacCready, P.: The estuarine circulation, Annu. Rev. Fluid Mech., 46, 175–197, https://doi.org/10.1146/annurev-fluid-010313-141302, 2014. a
Geyer, W. R. and Signell, R. P.: A reassessment of the role of tidal dispersion in estuaries and bays, Estuaries, 15, 97–108, https://doi.org/10.2307/1352684, 1992. a
Godin, G.: Compact approximations to the bottom friction term, for the study of tides propagating in channels, Cont. Shelf Res., 11, 579–589, https://doi.org/10.1016/0278-4343(91)90013-V, 1991. a
Godin, G.: The propagation of tides up rivers with special considerations on the upper Saint Lawrence River, Estuar. Coast. Shelf Sci., 48, 307–324, https://doi.org/10.1006/ecss.1998.0422, 1999. a
Gong, W., Maa, J. P.-Y., Hong, B., and Shen, J.: Salt transport during a dry season in the Modaomen Estuary, Pearl River Delta, China, Ocean Coast. Manag., 100, 139–150, https://doi.org/10.1016/j.ocecoaman.2014.03.024, 2014. a
Huismans, Y. and Plieger, R.: Verondieping Oude Maas als potentiele maatregel tegen verzilting: een verkenning, Tech. rep., Deltares, 11202241-003-ZWS-0003, 2019 (in Dutch). a
Huismans, Y., Leummens, L., Rodrigo, S., Laan, S., Kranenburg, W., and van der WIjk, R.: Extra debiet over stuw Hagestein voor het tegengaan van verzilting van de Lek, Tech. rep., Deltares, 11210363-001-ZKS-0001, 2024 (in Dutch). a
Kolb, P., Zorndt, A., Burchard, H., Gräwe, U., and Kösters, F.: Modelling the impact of anthropogenic measures on saltwater intrusion in the Weser estuary, Ocean Sci., 18, 1725–1739, https://doi.org/10.5194/os-18-1725-2022, 2022. a
Kranenburg, W., Van der Kaaij, T., Tiessen, M., Friocourt, Y., and Blaas, M.: Salt intrusion in the Rhine Meuse Delta: Estuarine circulation, tidal dispersion or surge effect, in: Proceedings of the 39th IAHR World Congress, 19–24 June 2022, Granada, Spain, International Association for Hydro-Environment Engineering and Research (IAHR), 5601–5608, https://doi.org/10.3850/IAHR-39WC2521711920221058, 2022. a, b
Laan, S., Chavarrias, V., Huismans, Y., and van der Wijk, R.: Verzilting Hollandsche IJssel en Lek, Tech. rep., Deltares, 11206830-017-ZWS-0001, 2021 (in Dutch). a
Laan, S., Huismans, Y., Rodrigo, S., Leummens, L., and Kranenburg, W.: Effect bodemligging op verzilting Nieuwe Waterweg, Nieuwe Maas en Lek, Tech. rep., Deltares, 11208075-010-ZWS-0001, 2023 (in Dutch). a
Liu, C., Yu, M., Jia, L., Cai, H., and Chen, X.: Impacts of physical alterations on salt transport during the dry season in the Modaomen Estuary, Pearl River Delta, China, Estuar. Coast. Shelf Sci., 227, 106345, https://doi.org/10.1016/j.ecss.2019.106345, 2019. a, b, c
Liu, J., Hetland, R., Yang, Z., Wang, T., and Sun, N.: Response of salt intrusion in a tidal estuary to regional climatic forcing, Environ. Res. Lett., 19, 074019, https://doi.org/10.1088/1748-9326/ad4fa1, 2024. a
MacCready, P.: Toward a unified theory of tidally-averaged estuarine salinity structure, Estuaries, 27, 561–570, https://doi.org/10.1007/BF02907644, 2004. a, b
MacCready, P.: Estuarine adjustment, J. Phys. Oceanogr., 37, 2133–2145, https://doi.org/10.1175/JPO3082.1, 2007. a, b
MacVean, L. J. and Stacey, M. T.: Estuarine Dispersion from Tidal Trapping: A New Analytical Framework, Estuar. Coast., 34, 45–59, https://doi.org/10.1007/s12237-010-9298-x, 2011. a
Maicu, F., De Pascalis, F., Ferrarin, C., and Umgiesser, G.: Hydrodynamics of the Po River-Delta-Sea System, J. Geophys. Res.-Ocean., 123, 6349–6372, https://doi.org/10.1029/2017JC013601, 2018. a
Martyr-Koller, R., Kernkamp, H., van Dam, A., van der Wegen, M., Lucas, L., Knowles, N., Jaffe, B., and Fregoso, T.: Application of an unstructured 3D finite volume numerical model to flows and salinity dynamics in the San Francisco Bay-Delta, Estuar. Coast. Shelf Sci., 192, 86–107, https://doi.org/10.1016/j.ecss.2017.04.024, 2017. a
Monismith, S.: An integral model of unsteady salinity intrusion in estuaries, J. Hydraul. Res., 55, 392–408, https://doi.org/10.1080/00221686.2016.1274682, 2017. a
Monismith, S., Kimmerer, W., Burau, J., and Stacey, M.: Structure and flow-induced variability of the subtidal salinity field in northern San Francisco Bay, J. Phys. Oceanogr., 32, 3003–3019, https://doi.org/10.1175/1520-0485(2002)032<3003:SAFIVO>2.0.CO;2, 2002. a, b
Moriasi, D. N., Gitau, M. W., Pai, N., and Daggupati, P.: Hydrologic and water quality models: Performance measures and evaluation criteria, T. ASABE, 58, 1763–1785, https://doi.org/10.13031/trans.58.10715, 2015. a
Murray, A. B.: Contrasting the goals, strategies, and predictions associated with simplified numerical models and detailed simulations, Geophys. Monogr.-Am. Geophys. Union, 135, 151–168, https://doi.org/10.1029/135GM11, 2003. a
Nash, J. and Sutcliffe, J.: River flow forecasting through conceptual models part I – A discussion of principles, J. Hydrol., 10, 282–290, https://doi.org/10.1016/0022-1694(70)90255-6, 1970. a
Nguyen, A. D. and Savenije, H. H.: Salt intrusion in multi-channel estuaries: a case study in the Mekong Delta, Vietnam, Hydrol. Earth Syst. Sci., 10, 743–754, https://doi.org/10.5194/hess-10-743-2006, 2006. a
Okubo, A.: Effect of shoreline irregularities on streamwise dispersion in estuaries and other embayments, Neth. J. Sea Res., 6, 213–224, https://doi.org/10.1016/0077-7579(73)90014-8, 1973. a
Pritchard, D. W.: A study of the salt balance in a coastal plain estuary, J. Mar. Res., 13, 133–144, 1954. a
Qiu, C. and Zhu, J.: Assessing the Influence of Sea Level Rise on Salt Transport Processes and Estuarine Circulation in the Changjiang River Estuary, J. Coast. Res., 31, 661–670, https://doi.org/10.2112/JCOASTRES-D-13-00138.1, 2015. a
Qiu, C. and Zhu, J.-R.: Influence of seasonal runoff regulation by the Three Gorges Reservoir on saltwater intrusion in the Changjiang River Estuary, Cont. Shelf Res., 71, 16–26, https://doi.org/10.1016/j.csr.2013.09.024, 2013. a
Ralston, D. K. and Geyer, W. R.: Response to Channel Deepening of the Salinity Intrusion, Estuarine Circulation, and Stratification in an Urbanized Estuary, J. Geophys. Res.-Ocean., 124, 4784–4802, https://doi.org/10.1029/2019JC015006, 2019. a
Ralston, D. K., Geyer, W. R., and Lerczak, J. A.: Structure, variability, and salt flux in a strongly forced salt wedge estuary, J. Geophys. Res.-Ocean., 115, C06005, https://doi.org/10.1029/2009JC005806, 2010. a
Rijkswaterstaat: Waterinfo, Rijkswaterstaat [data set], https://waterinfo.rws.nl/, last access: 31 January 2024. a
Savenije, H. H.: Predictive model for salt intrusion in estuaries, J. Hydrol., 148, 203–218, https://doi.org/10.1016/0022-1694(93)90260-G, 1993. a
Scully, M. E. and Geyer, W. R.: The Role of Advection, Straining, and Mixing on the Tidal Variability of Estuarine Stratification, J. Phys. Oceanogr., 42, 855–868, https://doi.org/10.1175/JPO-D-10-05010.1, 2012. a
Siles-Ajamil, R., Díez-Minguito, M., and Losada, M.: Tide propagation and salinity distribution response to changes in water depth and channel network in the Guadalquivir River Estuary: An exploratory model approach, Ocean Coast. Manag., 174, 92–107, https://doi.org/10.1016/j.ocecoaman.2019.03.015, 2019. a
Walters, R.: A model for tides and currents in the English Channel and southern North Sea, Adv. Water Resour., 10, 138–148, https://doi.org/10.1016/0309-1708(87)90020-0, 1987. a
Wang, J., de Swart, H. E., and Dijkstra, Y. M.: Dependence of tides and river water transport in an estuarine network on river discharge, tidal forcing, geometry and sea level rise, Cont. Shelf Res., 225, 104476, https://doi.org/10.1016/j.csr.2021.104476, 2021. a
Warner, J., Schoellhamer, D., Burau, J., and Schladow, G.: Effects of tidal current phase at the junction of two straits, Cont. Shelf Res., 22, 1629–1642, https://doi.org/10.1016/S0278-4343(02)00026-2, 2002. a
Wei, X., Schramkowski, G. P., and Schuttelaars, H. M.: Salt dynamics in well-mixed estuaries: Importance of advection by tides, J. Phys. Oceanogr., 46, 1457–1475, https://doi.org/10.1175/JPO-D-15-0045.1, 2016. a, b
Wei, X., Williams, M. E., Brown, J. M., Thorne, P. D., and Amoudry, L. O.: Salt Intrusion as a Function of Estuary Length in Periodically Weakly Stratified Estuaries, Geophys. Res. Lett., 49, e2022GL099082, https://doi.org/10.1029/2022GL099082, 2022. a
Winterwerp, J. C.: Decomposition of the mass transport in narrow estuaries, Estuar. Coast. Shelf Sci., 16, 627–638, https://doi.org/10.1016/0272-7714(83)90075-6, 1983. a
Wu, S., Cheng, H., Xu, Y., Li, J., and Zheng, S.: Decadal changes in bathymetry of the Yangtze River Estuary: Human impacts and potential saltwater intrusion, Estuar. Coast. Shelf Sci., 182, 158–169, https://doi.org/10.1016/j.ecss.2016.10.002, 2016. a
Wullems, B. J. M., Brauer, C. C., Baart, F., and Weerts, A. H.: Forecasting estuarine salt intrusion in the Rhine–Meuse delta using an LSTM model, Hydrol. Earth Syst. Sci., 27, 3823–3850, https://doi.org/10.5194/hess-27-3823-2023, 2023. a
Xue, P., Chen, C., Ding, P., Beardsley, R. C., Lin, H., Ge, J., and Kong, Y.: Saltwater intrusion into the Changjiang River: A model-guided mechanism study, J. Geophys. Res.-Ocean., 114, C02006, https://doi.org/10.1029/2008JC004831, 2009. a
Zhang, E., Savenije, H. H., Wu, H., Kong, Y., and Zhu, J.: Analytical solution for salt intrusion in the Yangtze Estuary, China, Estuar. Coast. Shelf Sci., 91, 492–501, https://doi.org/10.1016/j.ecss.2010.11.008, 2011. a
Zhu, J., Ding, P., Zhang, L., Wu, H., and Cao, H.: Influence of the deep waterway project on the Changjiang Estuary, in: The environment in Asia Pacific harbours, Springer, 79–92, https://doi.org/10.1007/1-4020-3655-8_6, 2006. a
Short summary
We study salinity in estuaries consisting of a network of channels. To this end, we develop a model that computes the flow and salinity in such systems. We use the model to quantify the mechanisms by which salt is transported into estuarine networks, the response to changes in river discharge, and the impact of depth changes. Results show that when changing the depth of channels, the effects on salt intrusion into other channels in the network can be larger than the effect on the channel itself.
We study salinity in estuaries consisting of a network of channels. To this end, we develop a...
