Articles | Volume 20, issue 4
https://doi.org/10.5194/os-20-1013-2024
© 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-20-1013-2024
© 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 Aug 2024
Research article |
| 22 Aug 2024
| 22 Aug 2024
Mechanisms and intraseasonal variability in the South Vietnam Upwelling, South China Sea: the role of circulation, tides, and rivers
Université de Toulouse, LEGOS (CNES/CNRS/IRD/UT3), Toulouse, France
Thai To Duy
Institute of Oceanography (IO), Vietnam Academy of Science and Technology (VAST), Nha Trang, Vietnam
Patrick Marsaleix
Université de Toulouse, LEGOS (CNES/CNRS/IRD/UT3), Toulouse, France
Related authors
Quentin Desmet, Marine Herrmann, and Thanh Ngo-Duc
EGUsphere, https://doi.org/10.5194/egusphere-2025-1579, https://doi.org/10.5194/egusphere-2025-1579, 2025
This preprint is open for discussion and under review for Geoscientific Model Development (GMD).
Short summary
Short summary
Climate model performance at the air–sea interface has long been overlooked across the Southeast Asian seas. We thus assess various regional model physics configurations in this regard. Finding one optimal configuration is challenging: reliable rainfall rarely coincides with correct radiative heating. Simulations of rainfall however yield more dissensus, suggesting that this variable should be prioritized, for which the best results are obtained with the cumulus convection scheme of Tiedtke.
Lisa Weiss, Marine Herrmann, Patrick Marsaleix, Matthieu Bompoil, and Christophe Maes
EGUsphere, https://doi.org/10.5194/egusphere-2025-1918, https://doi.org/10.5194/egusphere-2025-1918, 2025
This preprint is open for discussion and under review for Geoscientific Model Development (GMD).
Short summary
Short summary
We developed a high-resolution ocean model to study the dispersion of marine debris across the Indian Ocean, from small coastal scales to the open sea. Our results show that both model resolution and the effect of wind-driven surface waves play a key role in shaping ocean circulation, seasonal energy budgets and floating debris trajectories. High-resolution currents and wave forcing increase the spread and distance traveled by drifting material, especially during monsoon periods.
Thanh Huyen Tran, Alexei Sentchev, Thai To Duy, Marine Herrmann, Sylvain Ouillon, and Kim Cuong Nguyen
Ocean Sci., 21, 1–18, https://doi.org/10.5194/os-21-1-2025, https://doi.org/10.5194/os-21-1-2025, 2025
Short summary
Short summary
For the first time, high-resolution surface current data from high-frequency radar have been obtained along the central and southern coasts of Vietnam, and combined with a modelling approach, this is helping scientists to understand coastal processes. The research showed that the surface circulation is driven not only by winds, but also by other factors. This can enrich public knowledge of the coastal dynamics that govern other environmental impacts along the coasts.
Adrien Garinet, Marine Herrmann, Patrick Marsaleix, and Juliette Pénicaud
Geosci. Model Dev., 17, 6967–6986, https://doi.org/10.5194/gmd-17-6967-2024, https://doi.org/10.5194/gmd-17-6967-2024, 2024
Short summary
Short summary
Mixing is a crucial aspect of the ocean, but its accurate representation in computer simulations is made challenging by errors that result in unwanted mixing, compromising simulation realism. Here we illustrate the spurious effect that tides can have on simulations of south-east Asia. Although they play an important role in determining the state of the ocean, they can increase numerical errors and make simulation outputs less realistic. We also provide insights into how to reduce these errors.
Ngoc B. Trinh, Marine Herrmann, Caroline Ulses, Patrick Marsaleix, Thomas Duhaut, Thai To Duy, Claude Estournel, and R. Kipp Shearman
Geosci. Model Dev., 17, 1831–1867, https://doi.org/10.5194/gmd-17-1831-2024, https://doi.org/10.5194/gmd-17-1831-2024, 2024
Short summary
Short summary
A high-resolution model was built to study the South China Sea (SCS) water, heat, and salt budgets. Model performance is demonstrated by comparison with observations and simulations. Important discards are observed if calculating offline, instead of online, lateral inflows and outflows of water, heat, and salt. The SCS mainly receives water from the Luzon Strait and releases it through the Mindoro, Taiwan, and Karimata straits. SCS surface interocean water exchanges are driven by monsoon winds.
Marine Herrmann, Thai To Duy, and Claude Estournel
Ocean Sci., 19, 453–467, https://doi.org/10.5194/os-19-453-2023, https://doi.org/10.5194/os-19-453-2023, 2023
Short summary
Short summary
The South Vietnam upwelling develops in summer along and off the Vietnamese coast. It brings cold and nutrient-rich waters to the surface, allowing photosynthesis essential to marine ecosystems and fishing resources. We show here that its daily variations are mainly due to the wind, thus predictable, in the southern shelf and coastal regions. However, they are more chaotic in the offshore area, and especially in the northern area, due to the influence of eddies of a highly chaotic nature.
Thai To Duy, Marine Herrmann, Claude Estournel, Patrick Marsaleix, Thomas Duhaut, Long Bui Hong, and Ngoc Trinh Bich
Ocean Sci., 18, 1131–1161, https://doi.org/10.5194/os-18-1131-2022, https://doi.org/10.5194/os-18-1131-2022, 2022
Short summary
Short summary
The South Vietnam Upwelling develops in the coastal and offshore regions of the southwestern South China Sea under the influence of summer monsoon winds. Cold, nutrient-rich waters rise to the surface, where photosynthesis occurs and is essential for fishing activity. We have developed a very high-resolution model to better understand the factors that drive the variability of this upwelling at different scales: daily chronology to summer mean of wind and mesoscale to regional circulation.
Violaine Piton, Marine Herrmann, Florent Lyard, Patrick Marsaleix, Thomas Duhaut, Damien Allain, and Sylvain Ouillon
Geosci. Model Dev., 13, 1583–1607, https://doi.org/10.5194/gmd-13-1583-2020, https://doi.org/10.5194/gmd-13-1583-2020, 2020
Short summary
Short summary
Consequences of tidal dynamics on hydro-sedimentary processes are a recurrent issue in estuarine and coastal processes studies, and accurate tidal solutions are a prerequisite for modeling sediment transport. This study presents the implementation and optimization of a model configuration in terms of bathymetry and bottom friction and assess the influence of these parameters on tidal solutions, in a macro-tidal environment: the Gulf of Tonkin (Vietnam).
Quentin Desmet, Marine Herrmann, and Thanh Ngo-Duc
EGUsphere, https://doi.org/10.5194/egusphere-2025-1579, https://doi.org/10.5194/egusphere-2025-1579, 2025
This preprint is open for discussion and under review for Geoscientific Model Development (GMD).
Short summary
Short summary
Climate model performance at the air–sea interface has long been overlooked across the Southeast Asian seas. We thus assess various regional model physics configurations in this regard. Finding one optimal configuration is challenging: reliable rainfall rarely coincides with correct radiative heating. Simulations of rainfall however yield more dissensus, suggesting that this variable should be prioritized, for which the best results are obtained with the cumulus convection scheme of Tiedtke.
Lisa Weiss, Marine Herrmann, Patrick Marsaleix, Matthieu Bompoil, and Christophe Maes
EGUsphere, https://doi.org/10.5194/egusphere-2025-1918, https://doi.org/10.5194/egusphere-2025-1918, 2025
This preprint is open for discussion and under review for Geoscientific Model Development (GMD).
Short summary
Short summary
We developed a high-resolution ocean model to study the dispersion of marine debris across the Indian Ocean, from small coastal scales to the open sea. Our results show that both model resolution and the effect of wind-driven surface waves play a key role in shaping ocean circulation, seasonal energy budgets and floating debris trajectories. High-resolution currents and wave forcing increase the spread and distance traveled by drifting material, especially during monsoon periods.
Thanh Huyen Tran, Alexei Sentchev, Thai To Duy, Marine Herrmann, Sylvain Ouillon, and Kim Cuong Nguyen
Ocean Sci., 21, 1–18, https://doi.org/10.5194/os-21-1-2025, https://doi.org/10.5194/os-21-1-2025, 2025
Short summary
Short summary
For the first time, high-resolution surface current data from high-frequency radar have been obtained along the central and southern coasts of Vietnam, and combined with a modelling approach, this is helping scientists to understand coastal processes. The research showed that the surface circulation is driven not only by winds, but also by other factors. This can enrich public knowledge of the coastal dynamics that govern other environmental impacts along the coasts.
Claude Estournel, Tristan Estaque, Caroline Ulses, Quentin-Boris Barral, and Patrick Marsaleix
EGUsphere, https://doi.org/10.5194/egusphere-2024-3880, https://doi.org/10.5194/egusphere-2024-3880, 2024
Short summary
Short summary
During the summer of 2022 in the eastern Gulf of Lion (NW Mediterranean), exceptionally warm temperatures were observed down to depths of 30 m, along with massive mortality of benthic species. It has been shown that these deep marine heatwaves are linked to south-easterly wind episodes, which induce deep plunges of surface water overheated by the atmospheric heatwave. These events are rare in summer, but their impact on ecosystems is dramatic and will only increase with climate change.
Adrien Garinet, Marine Herrmann, Patrick Marsaleix, and Juliette Pénicaud
Geosci. Model Dev., 17, 6967–6986, https://doi.org/10.5194/gmd-17-6967-2024, https://doi.org/10.5194/gmd-17-6967-2024, 2024
Short summary
Short summary
Mixing is a crucial aspect of the ocean, but its accurate representation in computer simulations is made challenging by errors that result in unwanted mixing, compromising simulation realism. Here we illustrate the spurious effect that tides can have on simulations of south-east Asia. Although they play an important role in determining the state of the ocean, they can increase numerical errors and make simulation outputs less realistic. We also provide insights into how to reduce these errors.
Ngoc B. Trinh, Marine Herrmann, Caroline Ulses, Patrick Marsaleix, Thomas Duhaut, Thai To Duy, Claude Estournel, and R. Kipp Shearman
Geosci. Model Dev., 17, 1831–1867, https://doi.org/10.5194/gmd-17-1831-2024, https://doi.org/10.5194/gmd-17-1831-2024, 2024
Short summary
Short summary
A high-resolution model was built to study the South China Sea (SCS) water, heat, and salt budgets. Model performance is demonstrated by comparison with observations and simulations. Important discards are observed if calculating offline, instead of online, lateral inflows and outflows of water, heat, and salt. The SCS mainly receives water from the Luzon Strait and releases it through the Mindoro, Taiwan, and Karimata straits. SCS surface interocean water exchanges are driven by monsoon winds.
Marine Herrmann, Thai To Duy, and Claude Estournel
Ocean Sci., 19, 453–467, https://doi.org/10.5194/os-19-453-2023, https://doi.org/10.5194/os-19-453-2023, 2023
Short summary
Short summary
The South Vietnam upwelling develops in summer along and off the Vietnamese coast. It brings cold and nutrient-rich waters to the surface, allowing photosynthesis essential to marine ecosystems and fishing resources. We show here that its daily variations are mainly due to the wind, thus predictable, in the southern shelf and coastal regions. However, they are more chaotic in the offshore area, and especially in the northern area, due to the influence of eddies of a highly chaotic nature.
Thai To Duy, Marine Herrmann, Claude Estournel, Patrick Marsaleix, Thomas Duhaut, Long Bui Hong, and Ngoc Trinh Bich
Ocean Sci., 18, 1131–1161, https://doi.org/10.5194/os-18-1131-2022, https://doi.org/10.5194/os-18-1131-2022, 2022
Short summary
Short summary
The South Vietnam Upwelling develops in the coastal and offshore regions of the southwestern South China Sea under the influence of summer monsoon winds. Cold, nutrient-rich waters rise to the surface, where photosynthesis occurs and is essential for fishing activity. We have developed a very high-resolution model to better understand the factors that drive the variability of this upwelling at different scales: daily chronology to summer mean of wind and mesoscale to regional circulation.
Violaine Piton, Marine Herrmann, Florent Lyard, Patrick Marsaleix, Thomas Duhaut, Damien Allain, and Sylvain Ouillon
Geosci. Model Dev., 13, 1583–1607, https://doi.org/10.5194/gmd-13-1583-2020, https://doi.org/10.5194/gmd-13-1583-2020, 2020
Short summary
Short summary
Consequences of tidal dynamics on hydro-sedimentary processes are a recurrent issue in estuarine and coastal processes studies, and accurate tidal solutions are a prerequisite for modeling sediment transport. This study presents the implementation and optimization of a model configuration in terms of bathymetry and bottom friction and assess the influence of these parameters on tidal solutions, in a macro-tidal environment: the Gulf of Tonkin (Vietnam).
Related subject area
Approach: Numerical Models | Properties and processes: Coastal and near-shore processes
Wave-resolving Voronoi model of the Rouse number for sediment entrainment
River discharge impacts coastal southeastern tropical Atlantic sea surface temperature and circulation: a model-based analysis
The influence of a submarine canyon on the wind-driven downwelling circulation over the continental shelf
Alongshore sediment transport analysis for a semi-enclosed basin: a case study of the Gulf of Riga, the Baltic Sea
Anthropogenic pressures driving the salinity intrusion in the Guadalquivir estuary: insights from 1D numerical simulations
Application of wave–current coupled sediment transport models with variable grain properties for coastal morphodynamics: a case study of the Changhua River, Hainan
Dynamics of salt intrusion in complex estuarine networks: an idealised model applied to the Rhine–Meuse Delta
Extreme sensitivity of the northeastern Gulf of Lion (western Mediterranean) to subsurface heatwaves: Physical processes and devastating impacts on ecosystems in the summer of 2022
Influence of river runoff and precipitation on the seasonal and interannual variability of sea surface salinity in the eastern North Tropical Atlantic
Coupling ocean currents and waves for seamless cross-scale modeling during Medicane Ianos
A three-quantile bias correction with spatial transfer for the correction of simulated European river runoff to force ocean models
Coupling of numerical groundwater-ocean models to improve understanding of the coastal zone
Flow patterns, hotspots and connectivity of land-derived substances at the sea surface of Curaçao in the Southern Caribbean
Monsoonal influence on floating marine litter pathways in the Bay of Bengal
High-resolution numerical modelling of seasonal volume, freshwater, and heat transport along the Indian coast
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
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
Johannes Lawen
Ocean Sci., 21, 877–896, https://doi.org/10.5194/os-21-877-2025, https://doi.org/10.5194/os-21-877-2025, 2025
Short summary
Short summary
A new Voronoi-mesh-based coastal ocean model has been developed as an alternative to triangle-mesh-based models. The finite volume model has been generalized to run simulations on any mesh type, including triangle, Voronoi, Octree, structured, and mixed meshes. Wave-resolving simulations were conducted for coastal developments to resolve small scales in distributions of the Rouse number. The model has been validated using five tidal time series.
Léo C. Aroucha, Joke F. Lübbecke, Peter Brandt, Franziska U. Schwarzkopf, and Arne Biastoch
Ocean Sci., 21, 661–678, https://doi.org/10.5194/os-21-661-2025, https://doi.org/10.5194/os-21-661-2025, 2025
Short summary
Short summary
The west African coastal region sustains highly productive fisheries and marine ecosystems influenced by sea surface temperature. We use oceanic models to show that the freshwater input from land to ocean strengthens a surface northward (southward) coastal current north (south) of the Congo River mouth, promoting a transfer of cooler (warmer) waters to north (south) of the Congo discharge location. We highlight the significant impact of river discharge on ocean temperatures and circulation.
Pedro A. Figueroa, Gonzalo S. Saldías, and Susan E. Allen
Ocean Sci., 21, 643–659, https://doi.org/10.5194/os-21-643-2025, https://doi.org/10.5194/os-21-643-2025, 2025
Short summary
Short summary
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.
Tarmo Soomere, Mikołaj Zbigniew Jankowski, Maris Eelsalu, Kevin Ellis Parnell, and Maija Viška
Ocean Sci., 21, 619–641, https://doi.org/10.5194/os-21-619-2025, https://doi.org/10.5194/os-21-619-2025, 2025
Short summary
Short summary
Seemingly interconnected beaches are often separated by human-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.
Sara Sirviente, Juan J. Gomiz-Pascual, Marina Bolado-Penagos, Sabine Sauvage, José M. Sánchez-Pérez, and Miguel Bruno
Ocean Sci., 21, 515–535, https://doi.org/10.5194/os-21-515-2025, https://doi.org/10.5194/os-21-515-2025, 2025
Short summary
Short summary
The present study utilizes a 1D hydrodynamic model to examine the impact of anthropogenic pressures on saline intrusion in the Guadalquivir estuary. Water extraction by human activities has led to elevated salinity levels throughout the estuary, thereby disrupting its natural state. A more profound understanding of these effects is essential for the protection of the estuarine ecosystems.
Yuxi Wu, Enjin Zhao, Xiwen Li, and Shiyou Zhang
Ocean Sci., 21, 473–495, https://doi.org/10.5194/os-21-473-2025, https://doi.org/10.5194/os-21-473-2025, 2025
Short summary
Short summary
A comprehensive sand transfer model is proposed to study sediment dynamics in the lower reaches of the Changhua River on the island of Hainan. It captures the complex relationship between wave action, ocean currents, and sediment transport. Validated on the basis of on-site measurements, the model reveals significant sediment deposits which are significantly affected by coastal ocean currents and geological structures.
Bouke Biemond, Wouter M. Kranenburg, Ymkje Huismans, Huib E. de Swart, and Henk A. Dijkstra
Ocean Sci., 21, 261–281, https://doi.org/10.5194/os-21-261-2025, https://doi.org/10.5194/os-21-261-2025, 2025
Short summary
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.
Claude Estournel, Tristan Estaque, Caroline Ulses, Quentin-Boris Barral, and Patrick Marsaleix
EGUsphere, https://doi.org/10.5194/egusphere-2024-3880, https://doi.org/10.5194/egusphere-2024-3880, 2024
Short summary
Short summary
During the summer of 2022 in the eastern Gulf of Lion (NW Mediterranean), exceptionally warm temperatures were observed down to depths of 30 m, along with massive mortality of benthic species. It has been shown that these deep marine heatwaves are linked to south-easterly wind episodes, which induce deep plunges of surface water overheated by the atmospheric heatwave. These events are rare in summer, but their impact on ecosystems is dramatic and will only increase with climate change.
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
Short summary
Short summary
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.
Salvatore Causio, Seimur Shirinov, Ivan Federico, Giovanni De Cillis, Emanuela Clementi, Lorenzo Mentaschi, and Giovanni Coppini
EGUsphere, https://doi.org/10.5194/egusphere-2024-3517, https://doi.org/10.5194/egusphere-2024-3517, 2024
Short summary
Short summary
This study examines how waves and ocean currents interact during severe weather, focusing on Medicane Ianos, one of the strongest storms in the Mediterranean. Using advanced modeling, we created a unique system to simulate these interactions, capturing effects like changes in water levels and wind impact on waves. We validated our approach with ideal tests and real data from the storm.
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
Short summary
Short summary
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.
Jiangyue Jin, Manuel Espino, Daniel Fernández, and Albert Folch
EGUsphere, https://doi.org/10.5194/egusphere-2024-3384, https://doi.org/10.5194/egusphere-2024-3384, 2024
Short summary
Short summary
Coastal zones are crucial ecological areas, yet our understanding of groundwater-ocean interactions remains limited. Ocean and groundwater models typically operate independently, with ocean models ignoring submarine groundwater discharge and groundwater models viewing the ocean as a static boundary. This separation impedes accurate simulations. By integrating these models, we can capture real-time water flow and salt movement while considering factors such as tides.
Vesna Bertoncelj, Furu Mienis, Paolo Stocchi, and Erik van Sebille
EGUsphere, https://doi.org/10.5194/egusphere-2024-3112, https://doi.org/10.5194/egusphere-2024-3112, 2024
Short summary
Short summary
This study explores ocean currents around Curaçao and how land-derived substances like pollutants and nutrients travel in the water. Most substances move northwest, following the main current, but at times, ocean eddies spread them in other directions. This movement may link polluted areas to pristine coral reefs, impacting marine ecosystems. Understanding these patterns helps inform conservation and pollution management around Curaçao.
Lianne C. Harrison, Jennifer A. Graham, Piyali Chowdhury, Tiago A. M. Silva, Danja P. Hoehn, Alakes Samanta, Kunal Chakraborty, Sudheer Joseph, T. M. Balakrishnan Nair, and T. Srinivasa Kumar
EGUsphere, https://doi.org/10.5194/egusphere-2024-3096, https://doi.org/10.5194/egusphere-2024-3096, 2024
Short summary
Short summary
Particle tracking models allow us to explore pathways of floating marine litter, source-to-sink, between countries. This study showed the influence of seasonality for dispersal in Bay of Bengal and how ocean current forcing impacts model performance. Most litter beached on the country of origin, but there was a greater spread shown between countries during the post-monsoon period (Oct–Jan). Results will inform future model developments as well as management of marine litter in the region.
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
Short summary
Short summary
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.
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
Short summary
Short summary
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
Short summary
Short summary
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.
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
Short summary
Short summary
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
Short summary
Short summary
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
Short summary
Short summary
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
Short summary
Short summary
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
Short summary
Short summary
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
Short summary
Short summary
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
Bai, P., Ling, Z., Zhang, S., Xie, L., and Yang, J.: Fast-changing upwelling off the west coast of Hainan Island, Ocean Model., 148, 101589, https://doi.org/10.1016/j.ocemod.2020.101589, 2020. a
Benazzouz, A., Mordane, S., Orbi, A., Chagdali, M., Hilmi, K., Atillah, A., Pelegrí, J. L., and Demarcq, H.: An improved coastal upwelling index from sea surface temperature using satellite-based approach – The case of the Canary Current upwelling system, Cont. Shelf Res., 81, 38–54, https://doi.org/10.1016/j.csr.2014.03.012, 2014. a
Bombar, D., Dippner, J. W., Doan, H. N., Ngoc, L. N., Liskow, I., Loick-Wilde, N., and Voss, M.: Sources of new nitrogen in the Vietnamese upwelling region of the South China Sea, J. Geophys. Res.-Oceans, 115, 2008JC005154, https://doi.org/10.1029/2008JC005154, 2010. a
Carrere, L., Lyard, F., Cancet, M., Guillot, A., and Roblou, L.: FES 2012: A New Global Tidal Model Taking Advantage of Nearly 20 Years of Altimetry, in: 20 Years of Progress in Radar Altimatry, edited by: Ouwehand, L., ESA Special Publication, vol. 710, 13, ISBN 978-92-9221-274-2, 2013. a
Chen, C., Lai, Z., Beardsley, R. C., Xu, Q., Lin, H., and Viet, N. T.: Current separation and upwelling over the southeast shelf of Vietnam in the South China Sea, J. Geophys. Res.-Oceans, 117, 2011JC007150, https://doi.org/10.1029/2011JC007150, 2012. a, b
Da, N. D., Herrmann, M., Morrow, R., Niño, F., Huan, N. M., and Trinh, N. Q.: Contributions of Wind, Ocean Intrinsic Variability, and ENSO to the Interannual Variability of the South Vietnam Upwelling: A Modeling Study, J. Geophys. Res.-Oceans, 124, 6545–6574, https://doi.org/10.1029/2018JC014647, 2019. a, b, c, d, e, f, g, h
Desmet, Q.: Exploring the keys to advance air–sea coupled regional modeling for deeper insights into Southeast Asian climate, PhD thesis, Université de Toulouse, 2024. a
Dippner, J. W., Nguyen, K. V., Hein, H., Ohde, T., and Loick, N.: Monsoon-induced upwelling off the Vietnamese coast, Ocean Dynam., 57, 46–62, https://doi.org/10.1007/s10236-006-0091-0, 2007. a
Fang, G., Kwok, Y.-K., Yu, K., and Zhu, Y.: Numerical simulation of principal tidal constituents in the South China Sea, Gulf of Tonkin and Gulf of Thailand, Cont. Shelf Res., 19, 845–869, https://doi.org/10.1016/S0278-4343(99)00002-3, 1999. a
Guohong, F.: Tide and tidal current charts for the marginal seas adjacent to China, Chin. J. Oceanol. Limn., 4, 1–16, https://doi.org/10.1007/BF02850393, 1986. a
Herrmann, M. and To Duy, T.: Daily surface temperature from three sensitivity ensembles of June–September 2018 and tridimensional temperature, salinity and currents on 16 and 31 July 2018 over the South China Sea, Zenodo [data set], https://doi.org/10.5281/zenodo.10626112, 2024. a
Herrmann, M., Auger, P.-A., Ulses, C., and Estournel, C.: Long-term monitoring of ocean deep convection using multisensors altimetry and ocean color satellite data, J. Geophys. Res.-Oceans, 122, 1457–1475, https://doi.org/10.1002/2016JC011833, 2017. a
Herrmann, M., Ngo-Duc, T., and Trinh-Tuan, L.: Impact of climate change on sea surface wind in Southeast Asia, from climatological average to extreme events: results from a dynamical downscaling, Clim. Dynam., 54, 2101–2134, https://doi.org/10.1007/s00382-019-05103-6, 2020. a
Herrmann, M., Nguyen-Duy, T., Ngo-Duc, T., and Tangang, F.: Climate change impact on sea surface winds in Southeast Asia, Int. J. Climatol., 42, 3571–3595, https://doi.org/10.1002/joc.7433, 2021. a
Herrmann, M., To Duy, T., and Estournel, C.: Intraseasonal variability of the South Vietnam upwelling, South China Sea: influence of atmospheric forcing and ocean intrinsic variability, Ocean Sci., 19, 453–467, https://doi.org/10.5194/os-19-453-2023, 2023. a, b, c, d, e, f, g, h, i, j, k, l, m, n, o
Hunter, J.: A note on quadratic friction in the presence of tides, Estuar. Coast. Mar. Sci., 3, 473–475, https://doi.org/10.1016/0302-3524(75)90047-X, 1975. a
Isoguchi, O. and Kawamura, H.: MJO-related summer cooling and phytoplankton blooms in the South China Sea in recent years, Geophys. Res. Lett., 33, L16615, https://doi.org/10.1029/2006GL027046, 2006. a
Kuo, N.-J., Zheng, Q., and Ho, C.-R.: Response of Vietnam coastal upwelling to the 1997–1998 ENSO event observed by multisensor data, Remote Sens. Environ., 89, 106–115, https://doi.org/10.1016/j.rse.2003.10.009, 2004. a
Large, W. G. and Yeager, S. G.: Diurnal to Decadal Global Forcing For Ocean and Sea-Ice Models: The Data Sets and Flux Climatologies, Tech. Rep. NCAR/TN-460+STR, National Center for Atmospheric Research, Boulder, Colorado, https://doi.org/10.5065/D6KK98Q6, 2004. a
Li, Y., Han, W., Wilkin, J. L., Zhang, W. G., Arango, H., Zavala-Garay, J., Levin, J., and Castruccio, F. S.: Interannual variability of the surface summertime eastward jet in the South China Sea, J. Geophys. Res.-Oceans, 119, 7205–7228, https://doi.org/10.1002/2014JC010206, 2014. a, b
Li, Y., Curchitser, E. N., Wang, J., and Peng, S.: Tidal Effects on the Surface Water Cooling Northeast of Hainan Island, South China Sea, J. Geophys. Res.-Oceans, 125, e2019JC016016, https://doi.org/10.1029/2019JC016016, 2020. a, b
Lin, H., Liu, Z., Hu, J., Menemenlis, D., and Huang, Y.: Characterizing meso- to submesoscale features in the South China Sea, Prog. Oceanogr., 188, 102420, https://doi.org/10.1016/j.pocean.2020.102420, 2020. a
Lin, L., Liu, H., Huang, X., Fu, Q., and Guo, X.: Effect of tides on river water behavior over the eastern shelf seas of China, Hydrol. Earth Syst. Sci., 26, 5207–5225, https://doi.org/10.5194/hess-26-5207-2022, 2022. a
Liu, X., Wang, J., Cheng, X., and Du, Y.: Abnormal upwelling and chlorophyll-a concentration off South Vietnam in summer 2007, J. Geophys. Res.-Oceans, 117, C07021, https://doi.org/10.1029/2012JC008052, 2012. a
Loick-Wilde, N., Bombar, D., Doan, H. N., Nguyen, L. N., Nguyen-Thi, A. M., Voss, M., and Dippner, J. W.: Microplankton biomass and diversity in the Vietnamese upwelling area during SW monsoon under normal conditions and after an ENSO event, Prog. Oceanogr., 153, 1–15, https://doi.org/10.1016/j.pocean.2017.04.007, 2017. a
Loisel, H., Vantrepotte, V., Ouillon, S., Ngoc, D. D., Herrmann, M., Tran, V., Mériaux, X., Dessailly, D., Jamet, C., Duhaut, T., Nguyen, H. H., and Van Nguyen, T.: Assessment and analysis of the chlorophyll-a concentration variability over the Vietnamese coastal waters from the MERIS ocean color sensor (2002–2012), Remote Sens. Environ., 190, 217–232, https://doi.org/10.1016/j.rse.2016.12.016, 2017. a
Lu, W., Oey, L.-Y., Liao, E., Zhuang, W., Yan, X.-H., and Jiang, Y.: Physical modulation to the biological productivity in the summer Vietnam upwelling system, Ocean Sci., 14, 1303–1320, https://doi.org/10.5194/os-14-1303-2018, 2018. a
Lü, X., Qiao, F., Xia, C., Zhu, J., and Yuan, Y.: Upwelling off Yangtze River estuary in summer, J. Geophys. Res.-Oceans, 111, 2005JC003250, https://doi.org/10.1029/2005JC003250, 2006. a, b, c
Lü, X., Qiao, F., Wang, G., Xia, C., and Yuan, Y.: Upwelling off the west coast of Hainan Island in summer: Its detection and mechanisms, Geophys. Res. Lett., 35, L02604, https://doi.org/10.1029/2007GL032440, 2008. a
Marsaleix, P., Auclair, F., Floor, J. W., Herrmann, M. J., Estournel, C., Pairaud, I., and Ulses, C.: Energy conservation issues in sigma-coordinate free-surface ocean models, Ocean Model., 20, 61–89, https://doi.org/10.1016/j.ocemod.2007.07.005, 2008. a
Marsaleix, P., Michaud, H., and Estournel, C.: 3D phase-resolved wave modelling with a non-hydrostatic ocean circulation model, Ocean Model., 136, 28–50, https://doi.org/10.1016/j.ocemod.2019.02.002, 2019. a
Moon, J., Hirose, N., and Yoon, J.: Comparison of wind and tidal contributions to seasonal circulation of the Yellow Sea, J. Geophys. Res.-Oceans, 114, 2009JC005314, https://doi.org/10.1029/2009JC005314, 2009. a
Ngo, M. and Hsin, Y.: Impacts of Wind and Current on the Interannual Variation of the Summertime Upwelling Off Southern Vietnam in the South China Sea, J. Geophys. Res.-Oceans, 126, e2020JC016892, https://doi.org/10.1029/2020JC016892, 2021. a, b, c
Nguyen-Duy, T., Ayoub, N. K., De-Mey-Frémaux, P., and Ngo-Duc, T.: How sensitive is a simulated river plume to uncertainties in wind forcing? A case study for the Red River plume (Vietnam), Ocean Model., 186, 102256, https://doi.org/10.1016/j.ocemod.2023.102256, 2023. a
Ni, Q., Zhai, X., Wilson, C., Chen, C., and Chen, D.: Submesoscale Eddies in the South China Sea, Geophys. Res. Lett., 48, e2020GL091555, https://doi.org/10.1029/2020GL091555, 2021. a, b
Pairaud, I., Lyard, F., Auclair, F., Letellier, T., and Marsaleix, P.: Dynamics of the semi-diurnal and quarter-diurnal internal tides in the Bay of Biscay. Part 1: Barotropic tides, Cont. Shelf Res., 28, 1294–1315, https://doi.org/10.1016/j.csr.2008.03.004, 2008. a
Pairaud, I. L., Auclair, F., Marsaleix, P., Lyard, F., and Pichon, A.: Dynamics of the semi-diurnal and quarter-diurnal internal tides in the Bay of Biscay. Part 2: Baroclinic tides, Cont. Shelf Res., 30, 253–269, https://doi.org/10.1016/j.csr.2009.10.008, 2010. a
Phan, H. M., Ye, Q., Reniers, A. J., and Stive, M. J.: Tidal wave propagation along The Mekong deltaic coast, Estuar. Coast. Shelf S., 220, 73–98, https://doi.org/10.1016/j.ecss.2019.01.026, 2019. a
Rodi, W.: Examples of calculation methods for flow and mixing in stratified fluid, J. Geophys. Res., 92, 5305–5328, 1987. a
Sérazin, G., Penduff, T., Grégorio, S., Barnier, B., Molines, J.-M., and Terray, L.: Intrinsic Variability of Sea Level from Global Ocean Simulations: Spatiotemporal Scales, J. Climate, 28, 4279–4292, https://doi.org/10.1175/JCLI-D-14-00554.1, 2015. a
To Duy, T., Herrmann, M., Estournel, C., Marsaleix, P., Duhaut, T., Bui Hong, L., and Trinh Bich, N.: The role of wind, mesoscale dynamics, and coastal circulation in the interannual variability of the South Vietnam Upwelling, South China Sea – answers from a high-resolution ocean model, Ocean Sci., 18, 1131–1161, https://doi.org/10.5194/os-18-1131-2022, 2022. a, b, c, d, e, f, g, h, i, j, k, l, m, n, o
Trinh, N. B., Marsaleix, P., Estournel, C., Herrmann, M., Ulses, C., Duhaut, T., Shearman, R. K., and To-Duy, T.: High-resolution configuration of the hydrodynamical ocean model SYMPHONIE (version 2.4) over the South China Sea, Zenodo [code, data set], https://doi.org/10.5281/zenodo.7941495, 2023. a
Trinh, N. B., Herrmann, M., Ulses, C., Marsaleix, P., Duhaut, T., To Duy, T., Estournel, C., and Shearman, R. K.: New insights into the South China Sea throughflow and water budget seasonal cycle: evaluation and analysis of a high-resolution configuration of the ocean model SYMPHONIE version 2.4, Geosci. Model Dev., 17, 1831–1867, https://doi.org/10.5194/gmd-17-1831-2024, 2024. a, b, c
Ulses, C., Auger, P., Soetaert, K., Marsaleix, P., Diaz, F., Coppola, L., Herrmann, M., Kessouri, F., and Estournel, C.: Budget of organic carbon in the North-Western Mediterranean open sea over the period 2004–2008 using 3-D coupled physical-biogeochemical modeling, J. Geophys. Res.-Oceans, 121, 7026–7055, https://doi.org/10.1002/2016JC011818, 2016. a
Waldman, R., Herrmann, M., Somot, S., Arsouze, T., Benshila, R., Bosse, A., Chanut, J., Giordani, H., Sevault, F., and Testor, P.: Impact of the Mesoscale Dynamics on Ocean Deep Convection: The 2012–2013 Case Study in the Northwestern Mediterranean Sea, J. Geophys. Res.-Oceans, 122, 8813–8840, https://doi.org/10.1002/2016JC012587, 2017. a
Waldman, R., Somot, S., Herrmann, M., Sevault, F., and Isachsen, P. E.: On the Chaotic Variability of Deep Convection in the Mediterranean Sea, Geophys. Res. Lett., 45, 2433–2443, https://doi.org/10.1002/2017GL076319, 2018. a, b
Wang, G., Chen, D., and Su, J.: Generation and life cycle of the dipole in the South China Sea summer circulation, J. Geophys. Res.-Oceans, 111, 2005JC003314, https://doi.org/10.1029/2005JC003314, 2006. a
Wang, Y., Fang, G., Wei, Z., Qiao, F., and Chen, H.: Interannual variation of the South China Sea circulation and its relation to El Niño, as seen from a variable grid global ocean model, J. Geophys. Res., 111, C11S14, https://doi.org/10.1029/2005JC003269, 2006. a
Wu, H., Gu, J., and Zhu, P.: Winter Counter-Wind Transport in the Inner Southwestern Yellow Sea, J. Geophys. Res.-Oceans, 123, 411–436, https://doi.org/10.1002/2017JC013403, 2018. a
Wyrtki, K.: Physical Oceanography of the Southeast Asian waters, Naga Report 2, The University of California Scripps Institution of Oceanography, La Jolla, California, https://escholarship.org/uc/item/49n9x3t4 (last access: 17 August 2024), 1961. a
Xie, S.-P.: Summer upwelling in the South China Sea and its role in regional climate variations, J. Geophys. Res., 108, 3261, https://doi.org/10.1029/2003JC001867, 2003. a, b
Xie, S.-P., Chang, C.-H., Xie, Q., and Wang, D.: Intraseasonal variability in the summer South China Sea: Wind jet, cold filament, and recirculations, J. Geophys. Res., 112, C10008, https://doi.org/10.1029/2007JC004238, 2007. a
Xiu, P., Chai, F., Shi, L., Xue, H., and Chao, Y.: A census of eddy activities in the South China Sea during 1993–2007, J. Geophys. Res., 115, C03012, https://doi.org/10.1029/2009JC005657, 2010. a
Xu, Y., Liu, X., Zhou, F., Chen, X., Ye, R., and Chen, D.: Tide-Induced Upwelling and Its Three-Dimensional Balance of the Vertical Component of Vorticity in the Wider Area of the Bohai Strait, Journal of Marine Science and Engineering, 11, 1839, https://doi.org/10.3390/jmse11091839, 2023. a
Yu, Y., Wang, Y., Cao, L., Tang, R., and Chai, F.: The ocean-atmosphere interaction over a summer upwelling system in the South China Sea, J. Marine Syst., 208, 103360, https://doi.org/10.1016/j.jmarsys.2020.103360, 2020. a, b
Zheng, Z.-W., Zheng, Q., Kuo, Y.-C., Gopalakrishnan, G., Lee, C.-Y., Ho, C.-R., Kuo, N.-J., and Huang, S.-J.: Impacts of coastal upwelling off east Vietnam on the regional winds system: An air-sea-land interaction, Dynam. Atmos. Oceans, 76, 105–115, https://doi.org/10.1016/j.dynatmoce.2016.10.002, 2016. a, b
Short summary
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.
In summer, deep, cold waters rise to the surface along and off the Vietnamese coast. This...
