Adaptive management in Kushiro Wetland in the context of salt wedge intrusion due to sea level rise

Nakamoto, Atsushi; Nakayama, Keisuke; Shintani, Tetsuya; Maruya, Yasuyuki; Komai, Katsuaki; Ishida, Tamao; Makiguchi, Yoshihiro

doi:10.3178/hrl.7.1

Cited by 19 publications

(6 citation statements)

References 12 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…In this study, a three-dimensional non-hydrostatic model, Fantom3D, was used to analyze the breaking of shoaling ISWs. Fantom3D is an object-oriented parallel computing model for the analysis of environmental fluid dynamics [44][45][46][47], based on the Reynolds-averaged Navier-Stokes (RANS) equations in the height (z) coordinate. A free surface was applied to the top boundary, and a no-slip and slip conditions were given on the bottom and lateral boundaries, respectively.…”

Section: A Present Numerical Experimentsmentioning

confidence: 99%

Classification of internal solitary wave breaking over a slope

et al. 2019

Self Cite

View full text Add to dashboard Cite

Breaking of shoaling internal solitary waves (ISWs) is important for mixing and mass transport processes in oceans and lakes. For ISWs in a two-layer stratified fluid, previous studies identified four breaker types: surging, plunging, collapsing, and fission. The latest classification of these breaker types is based on the wave slope S w and the bottom slope S; however, this classification was found to be unsatisfactory in delineating collapsing and plunging breakers. The present study proposes a new classification for these two breaker types using extended data sets, consisting of published experimental data and the results of new numerical simulations. It was found that a single nondimensional index B ISW = (S/S w)Re ISW 2 delineates collapsing and plunging breakers in the extended data, where Re ISW is a new wave Reynolds number that accounts for nonlinear wave steepening.

show abstract

Section: A Present Numerical Experimentsmentioning

confidence: 99%

Classification of internal solitary wave breaking over a slope

et al. 2019

Self Cite

View full text Add to dashboard Cite

show abstract

“…A three-dimensional nonhydrostatic model, Fantom, was used to analyze the breaking of internal Kevin waves shoaling on the uniform slope. Fantom is an object-oriented parallel computing model that has been applied to investigate not only real scale phenomena (Maruya et al, 2010;Nakamoto et al, 2013;Nakayama et al, 2014Nakayama et al, , 2016 but also laboratory-scale phenomena (Nakayama et al, 2012(Nakayama et al, , 2020Nakayama, Kakinuma, and Tsuji, 2019). Fantom is based on Direct numerical simulation (DNS) as well as a generic length scale (GLS) equation model (Jones & Launder, 1972;Umlauf & Burchard, 2003), with a partial cell scheme used here to represent the uniform bottom slope in the z coordinate bathymetry (Adcroft et al, 1997).…”

Section: Numerical Simulationsmentioning

confidence: 99%

Breaking of Internal Kelvin Waves Shoaling on a Slope

et al. 2020

View full text Add to dashboard Cite

In stratified flow, breaking of internal waves over slopes induces resuspension of bottom sediments and transport of mass. When internal waves shoal and break, flow dynamics and mass transport differ significantly according to whether the Coriolis force is included or neglected. Despite its importance, the currents generated by breaking internal Kelvin waves remain uninvestigated. Therefore, this study considers breaking of internal waves over a uniform slope under Coriolis with equivalent upper-and lower-layer depths. Laboratory experiments, using a 6.0-m rotating tank, were undertaken to visualize currents using particle image velocimetry. Experimental data validated a three-dimensional fluid dynamics model, in which a phase-averaged velocity (residual jet) was simulated to occur at the lateral wall (to the right) of the progressive internal Kelvin waves in the breaking zone, with the generation of an oblique downslope return flow (downdraft) under Coriolis. The geostrophic balance drove the residual jet, and the equation for estimating the residual current, due to the jet, was formulated and was discussed by referring a coastal jet in Lake Erie. The results provide insight on mass transport in lakeshore and coastal zones. Plain Language Summary The key idea of the present study is the "residual jet" which occurs at the lateral wall on the right side of the progressive internal Kelvin waves due to breaking over a uniform slope. We conducted laboratory experiments by using a rotating tank, and internal Kelvin wave breaking was visualized by using particle image velocimetry (PIV) method. Also, using a three-dimensional fluid dynamics model, a residual jet was demonstrated to occur with the generation of an oblique downdraft running down the slope under Coriolis, which was verified through the laboratory experiments. We found that the geostrophic balance drives a residual jet, and the equation for estimating the residual current, due to the jet, was formulated and was discussed by referring a coastal jet in Lake Erie. Therefore, the paper will provide the oceanography communities with a new understanding of the effect of internal Kelvin wave breaking, and the associated residual currents, on long-term mass transport.

show abstract

“…A three‐dimensional nonhydrostatic model, FANTOM3D, was used to clarify the role of negative wind curl on the occurrence of the depression of the isopycnals due to Ekman transport [ Maruya et al ., ; Nakayama et al ., ; Nakamoto et al ., ] and the associated anticyclonic horizontal circulation. FANTOM3D is an object‐oriented programming model for the analysis of environmental fluid mechanics.…”

Section: Numerical Solutionsmentioning

confidence: 99%

“…A three-dimensional nonhydrostatic model, FANTOM3D, was used to clarify the role of negative wind curl on the occurrence of the depression of the isopycnals due to Ekman transport [Maruya et al, 2010;Nakayama et al, 2012;Nakamoto et al, 2013] topographic effects accurately and to prevent numerical diffusion, the z coordinate system was employed [Nakayama, 2006;Simanjuntak et al, 2009;Nakayama and Imberger, 2010]. The vertical mixing scheme was based on large-eddy simulation [Orlandi, 2000], the advection scheme for momentum and scalar was ULTIMATE-QUICKEST [Leonard, 1991] while for subgrid-scale turbulent kinetic energy a first-order upwind scheme was used.…”

Section: Model Description and Configurationmentioning

confidence: 99%

“…We briefly introduce the study site, Tokyo Bay, in section . We present the results of field experiments in section , and use a numerical computational model, FANTOM3D [ Maruya et al ., ; Nakayama et al ., ; Nakamoto et al ., ] to understand the results of field experiments in section . In section , we investigate the role of nonlinearity in a surface Ekman layer both theoretically and numerically.…”

Section: Introductionmentioning

confidence: 99%

See 1 more Smart Citation

Horizontal and residual circulations driven by wind stress curl in Tokyo Bay

Nakayama

Shintani

Shimizu

et al. 2014

J. Geophys. Res. Oceans

View full text Add to dashboard Cite

This study investigates the horizontal and residual circulations in Tokyo Bay using field observations, numerical simulations, and theoretical analysis. Numerical simulations show that the observed deepening of isopycnals and associated anticyclonic horizontal circulation in the bay head are mainly driven by negative wind stress curl. The effects of river discharge, surface heat fluxes, and tides are found to be small. Under strong wind events, the wind stress curl over the bay head can be large enough to make the surface Ekman layer strongly nonlinear. Theoretical and numerical analyses show that, under large negative wind stress curl, the nonlinearity tends to induce positive pumping velocity (at the base of the surface mixed layer) that counteracts the Ekman pumping; however, the typical duration of wind events in the bay head is not long enough to induce positive pumping under negative wind stress curl. These results and historical wind data suggest that the average horizontal circulation and residual circulation immediately below the surface mixed layer in Tokyo Bay are, respectively, cyclonic and convergent in summer but anticyclonic and divergent in winter.

show abstract

Adaptive management in Kushiro Wetland in the context of salt wedge intrusion due to sea level rise

Cited by 19 publications

References 12 publications

Classification of internal solitary wave breaking over a slope

Classification of internal solitary wave breaking over a slope

Breaking of Internal Kelvin Waves Shoaling on a Slope

Horizontal and residual circulations driven by wind stress curl in Tokyo Bay

Contact Info

Product

Resources

About