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.
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
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
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.
Claude Estournel, Tristan Estaque, Caroline Ulses, Quentin-Boris Barral, and Patrick Marsaleix
Ocean Sci., 21, 1487–1503, https://doi.org/10.5194/os-21-1487-2025, https://doi.org/10.5194/os-21-1487-2025, 2025
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 southeasterly 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.
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
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
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.
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...