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Stratification and salt-wedge in the Seomjin river estuary under the idealized tidal influence

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Abstract

Advection, straining, and vertical mixing play primary roles in the process of estuarine stratification. Estuaries can be classified as salt-wedge, partially-mixed or well-mixed depending on the vertical density structure determined by the balancing of advection, mixing and straining. In particular, straining plays a major role in the stratification of the estuarine water body along the estuarine channel. Also, the behavior of a salt wedge with a halocline shape in a stratified channel can be controlled by the competition between straining and mixing induced by buoyancy from the riverine source and tidal forcing. The present study uses Finite Volume Coastal Ocean Model (FVCOM) to show that straining and vertical mixing play major roles in controlling along-channel flow and stratification structures in the Seomjin river estuary (SRE) under idealized conditions. The Potential Energy Anomaly (PEA) dynamic equation quantifies the governing processes thereby enabling the determination of the stratification type. By comparing terms in the equation, we examined how the relative strengths of straining and mixing alter the stratification types in the SRE due to changes in river discharge and the depth resulting from dredging activities. SRE under idealized tidal forcing tends to be partially-mixed based on an analysis of the balance between terms and the vertical structure of salinity, and the morphological and hydrological change in SRE results in the shift of stratification type. While the depth affects the mixing, the freshwater discharge mainly controls the straining, and the balance between mixing and straining determines the final state of the stratification in an estuarine channel. As a result, the development and location of a salt wedge along the channel in a partially mixed and highly stratified condition is also determined by the ratio of straining to mixing. Finally, our findings confirm that the contributions of mixing and straining can be assessed by using the conventional non-dimensional parameters with respect to salt-wedge behavior.

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References

  • de Boer GJ, Pietrzak JD, Winterwerp JC (2008) Using the potential energy anomaly equation to investigate tidal straining and advection of stratification in a region of freshwater influence. Ocean Model 22:1–11. doi:10.1016/j.ocemod.2007.12.003

    Article  Google Scholar 

  • Burchard H, Schulz E, Schuttelaars HM (2014) Impact of estuarine convergence on residual circulation in tidally energetic estuaries and inlets. Geophys Res Lett 41:913–919. doi:10.1002/2013GL058494

    Article  Google Scholar 

  • Burchard H, Hofmeister R (2008) A dynamic equation for the potential energy anomaly for analyzing mixing and stratification in estuaries and coastal seas. Estuar Coast Shelf S 77:679–687. doi:10.1016/j.ecss.2007.10.025

    Article  Google Scholar 

  • Chen C, Liu H, Beardsley RC (2003) An unstructured grid, finitevolume, three-dimensional, primitive equation ocean model: application to coastal ocean and estuaries J Atmos Ocean Tech 20:159–186

    Article  Google Scholar 

  • D’Adamo N, Lukatelich R (1985) Water quality of the Murray river estuary: summary report. Centre for Water Research, The University of Western Australia, 17 p

    Google Scholar 

  • Fischer HB (1972) Mass transport mechanisms in partially stratified estuaries. J Fluid Mech 53:672–687

    Article  Google Scholar 

  • Fischer HB (1976) Mixing and dispersion in estuaries. Annu Rev Fluid Mech 8:107–133. doi:10.1146/annurev.fl.08.010176.000543

    Article  Google Scholar 

  • Geyer WR, Mac Cready P (2014) The estuarine circulation. Annu Rev Fluid Mech 46:175–197. doi:10.1146/annurev-fluid-010313- 141302

    Article  Google Scholar 

  • Giddings SN, Fong DA, Monismith SG (2011) Role of straining and advection in the intratidal evolution of stratification, vertical mixing, and longitudinal dispersion of a shallow, macrotidal, salt wedge estuary. J Geophys Res 116:C03003. doi:10.1029/2010JC006482

    Article  Google Scholar 

  • Hansen DV, Rattray Jr M (1966) New dimensions in estuary classification. Limnol Oceanogr 11:319–326

    Article  Google Scholar 

  • Hoitink AJK, van Maren DS, Hoekstra P (2011) Mixing and stratification in a tropical tidal embayment subject to a distributed freshwater source. J Marine Syst 88:34–44. doi:10.1016/ j.jmarsys.2011.02.015

    Article  Google Scholar 

  • Hofmeister R, Burchard H, Bolding K (2009) A three-dimensional model study on process of stratification and de-stratification in Limfjord. Cont Shelf Res 29:1515–1524. doi:10.1016/ j.csr.2009.04.004

    Article  Google Scholar 

  • Jang D, Hwang JH, Park YG, Park SH (2012) A study on salt wedge and river plume in the Seom-Jin river and estuary. KSCE J Civ Eng 16:676–688. doi:10.1007/s12205-012-1521-9

    Article  Google Scholar 

  • Jay DA, Musiak JD (1994) Particle trapping in estuarine tidal flows. J Geophys Res 99:20445–20461. doi:10.1029/94JC00971

    Article  Google Scholar 

  • Kasai A, Kurikawa Y, Ueno M, Robert D, Yamashita Y (2010) Saltwedge intrusion of seawater and its implication for phytoplankton dynamics in the Yura estuary, Japan. Estuar Coast Shelf S 86:408–414. doi:10.1016/j.ecss.2009.06.001

    Article  Google Scholar 

  • Kuo AY, Neilson BJ (1987) Hypoxia and salinity in Virginia estuaries. Estuaries 10:277–283. doi:10.2307/1351884

    Article  Google Scholar 

  • Kurup GR, Hamilton DP, Patterson JC (1998) Modelling effect of seasonal flow variations on the position of salt wedge in a microtidal estuary. Estuar Coast Shelf S 47:191–208. doi:10.1006/ecss.1998.0346

    Article  Google Scholar 

  • Li M, Trowbridge J, Geyer WR (2007) Asymmetric tidal mixing due to the horizontal density gradient. J Phys Oceanogr 38:418–434

    Article  Google Scholar 

  • MacCready P, Geyer WR (2010) Advances in estuarine physics. Ann Rev Mar Sci 2:35–58. doi:10.1146/annurev-marine- 120308-081015

    Article  Google Scholar 

  • Mellor GL, Yamada T (1982) Development of a turbulence closure model for geophysical fluid problems. Rev Geophys Space Phys 20:851–875. doi:10.1029/RG020i004p00851

    Article  Google Scholar 

  • Nepf HM, Geyer WR (1996) Intratidal variations in stratification and mixing in the Hudson estuary. J Geophys Res 101:12079–12086

    Article  Google Scholar 

  • Oey LY (1984) On steady salinity distribution and circulation in partial mixed and well mixed estuaries. J Phys Oceanogr 14:629–645

    Article  Google Scholar 

  • Pinet PR (2011) Invitation to oceanography. Jones & Bartlett Publishers, 614 p

    Google Scholar 

  • Prandle D (2004) Saline intrusion in partially mixed estuaries. Estuar Coast Shelf S 59:385–397. doi:10.1016/j.ecss.2003.10.001

    Article  Google Scholar 

  • Pritchard DW (1955) Estuarine circulation patterns. Proc Am Soc Civil Eng 81:1–11

    Google Scholar 

  • Ralston DK, Geyer WR, Lerczak JA, Scully ME (2010) Turbulent mixing in a strongly forced salt wedge estuary. J Geophys Res 115:C12024. doi:10.1029/2009JC006061

    Article  Google Scholar 

  • Schijf JB, Schonfeld JC (1953) Theoretical considerations on the motion on salt and fresh water. In: Proceedings - Minnesota International Hydraulic Convention, University of Minnesota, Minneapolis, 1–4 Sep 1953, pp 321–333

    Google Scholar 

  • Scully ME, Geyer WR (2012) The role of advection, straining, and mixing on the tidal variability of estuary stratification. J Phys Oceanogr 42:855–868

    Article  Google Scholar 

  • Shaha DC, Cho Y-K (2009) Comparison of empirical models with intensively observed data for prediction of salt intrusion in the Sumjin River estuary, Korea. Hydrol Earth Syst Sc 13:923–933

    Article  Google Scholar 

  • Shaha DC, Cho Y-K, Seo GH, Kim CS, Jung KT (2010) Using flushing rate to investigate spring-neap and spatial variations of gravitational circulation and tidal exchanges in an estuary. Hydrol Earth Syst Sc 14:1464–1476. doi:10.5194/hess-14-1465-2010

    Article  Google Scholar 

  • Sharples J, Simpson JH, Brubaker JM (1994) Observations and modelling of periodic stratification in the upper York river estuary, Virginia. Estuar Coast Shelf S 38:301–312

    Article  Google Scholar 

  • Sierra JP, Sanchez-Arcilla A, Gonzales Del Rio J, Flos J, Movellan E, Mosso C, Martinez R, Rodilla M, Falco S, Romero I (2002) Spatial distribution of nutrients in the Ebro estuary and plume. Cont Shelf Res 22:361–378. doi:10.1016/S0278-4343(01)00061-9

    Article  Google Scholar 

  • Sierra JP, Sanchez-Arcilla A, Figueras PA, Gonzales Del Rio J, Rassmussen EK, Mosso C (2004) Effects of discharge reductions on salt wedge dynamics of the Ebro river. River Res Appl 20:61–77. doi:10.1002/rra.721

    Article  Google Scholar 

  • Simpson JH, Hunter JR (1974) Fronts in the Irish sea. Nature 250:404–406. doi:10.1038/250404a0

    Article  Google Scholar 

  • Simpson JH (1981) The shelf-sea fronts: implications of their existence and behavior. Philos T R Soc Lond 302:531–546. doi:10.1098/rsta.1981.0181

    Article  Google Scholar 

  • Simpson JH, Brown J, Matthews J, Allen G (1990) Tidal straining, density currents, and stirring in the control of estuarine stratification. Estuaries 13:125–132. doi:10.2307/1351581

    Article  Google Scholar 

  • Simpson JH, Bos WG, Schirmer F, Souza AJ, Rippeth TP, Jones SE, Hydes D (1993) Periodic stratification in the Rhine ROFI in the north sea. Oceanol Acta 16(1):23–32

    Google Scholar 

  • Stacey MT, Ralston DK (2005) The scaling and structure of estuarine bottom boundary layer. J Phys Oceanogr 35:55–71

    Article  Google Scholar 

  • Stacey MT, Burau JR, Monismith SG (2001) Creation of residual flows in a partially stratified estuary. J Geophys Res 106(C8): 17013–17037

    Article  Google Scholar 

  • Stacey MT, Monismith SG, Burau JR (1999) Observations of turbulence in a partially stratified estuary. J Phys Oceanogr 29:1950–1970

    Article  Google Scholar 

  • Uncles RJ, Bale AJ, Howland RJN, Morris AW, Elliott RCA (1983) Salinity of surface water in a partially-mixed estuary, and its dispersion at low run-off. Oceanol Acta 6:289–296

    Google Scholar 

  • van Aken HM (1986) The onset of stratification in shelf seas due to differential advection in the presence of a salinity gradient. Cont Shelf Res 5:475–485. doi:10.1016/0278-4343(86)90071-3

    Article  Google Scholar 

  • Wang B, Giddings SN, Fringer OB, Gross ES, Fong DA (2011) Modeling and understanding turbulent mixing in a macrotidal salt wedge estuary. J Geophys Res 116:C02036. doi:10.1029/2010JC006135

    Google Scholar 

  • Wiles PJ, van Duren LA, Hase C, Larsen J, Simpson JH (2006) Stratification and mixing in the Limfjorden in relation to mussel culture. J Marine Syst 60:129–143

    Article  Google Scholar 

  • Zhang E, Savenije H, Wu H, Kong Y, Zhu J (2011) Analytical solution for salt intrusion in the Yangtze estuary, China. Estuar Coast Shelf S 91:492–501. doi:10.1016/j.ecss.2010.11.008

    Article  Google Scholar 

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Correspondence to Dongmin Jang.

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Hwang, J.H., Jang, D. & Kim, Y.H. Stratification and salt-wedge in the Seomjin river estuary under the idealized tidal influence. Ocean Sci. J. 52, 469–487 (2017). https://doi.org/10.1007/s12601-017-0050-3

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  • DOI: https://doi.org/10.1007/s12601-017-0050-3

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