Non-linear aspects of the tidal dynamics in the Sylt-Rømø Bight, south-eastern North Sea

Abstract. This study investigates the tidal dynamics in the Sylt-Rømø bight with a focus on the non-linear processes. The FESOM-C model was used as the numerical tool, which works with triangular, rectangular or mixed meshes and is equipped with a wetting/drying option. As the model's success at resolving currents largely depends on the quality of the bathymetric data, we have created a new bathymetric map for an area based on recent studies of Lister Deep, Lister Ley, and the Højer and Rømø Deep areas. This new bathymetric product made it feasible to work with high resolution grids (up to 2 m in the wetting/drying zone). As a result, we were able to study the tidal energy transformation and the role of higher harmonics in the domain in detail. For the first time, the tidal ellipses, maximum tidally-induced velocities, energy fluxes and residual circulation maps were constructed and analysed for the entire bight. Additionally, tidal asymmetry maps were introduced and constructed. The full analysis was performed on two grids with different structures and showed a convergence of the obtained results as well as fulfillment of the energy balance. A great deal of attention has been paid to the selection of open boundary conditions, model verification against available tide gauges, and recent ADCP data. The obtained results are necessary and useful benchmarks for further studies in the area, including baroclinic and sediment dynamics tasks.

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Non-linear aspects of the tidal dynamics in the Sylt-Rømø Bight, south-eastern North Sea

Ocean Science ◽

10.5194/os-15-1761-2019 ◽

2019 ◽

Vol 15 (6) ◽

pp. 1761-1782 ◽

Cited By ~ 3

Author(s):

Vera Fofonova ◽

Alexey Androsov ◽

Lasse Sander ◽

Ivan Kuznetsov ◽

Felipe Amorim ◽

...

Keyword(s):

Circulation Pattern ◽

Tidal Energy ◽

Current Data ◽

Open Boundary ◽

Open Boundary Conditions ◽

Residual Circulation ◽

Tidal Dynamics ◽

Linear Processes ◽

Non Linear ◽

Full Analysis

Abstract. This study is dedicated to the tidal dynamics in the Sylt-Rømø Bight with a focus on the non-linear processes. The FESOM-C model was used as the numerical tool, which works with triangular, rectangular or mixed grids and is equipped with a wetting/drying option. As the model's success at resolving currents largely depends on the quality of the bathymetric data, we have created a new bathymetric map for an area based on recent studies of Lister Deep, Lister Ley, Højer Deep and Rømø Deep. This new bathymetric product made it feasible to work with high-resolution grids (up to 2 m in the wetting/drying zone). As a result, we were able to study the tidal energy transformation and the role of higher harmonics in the domain in detail. For the first time, the tidal ellipses, maximum tidally induced velocities, energy fluxes and residual circulation maps were constructed and analysed for the entire bight. Additionally, tidal asymmetry maps were introduced and constructed. The full analysis was performed on two grids with different structures and showed a convergence of the results as well as fulfilment of the energy balance. A great deal of attention has been paid to the selection of open-boundary conditions, model validation against tide gauges and recent in situ current data. The tidal residual circulation and asymmetric tidal cycles largely define the circulation pattern, transport and accumulation of sediment, and the distribution of bedforms in the bight; therefore, the results presented in the article are necessary and useful benchmarks for further studies in the area, including baroclinic and sediment dynamics investigations.

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Tidal asymmetry in the Sylt-Romo Bight, south-eastern North Sea

10.5194/egusphere-egu2020-1359 ◽

2020 ◽

Author(s):

Vera Fofonova ◽

Alexey Androsov ◽

Lasse Sander ◽

Ivan Kuznetsov ◽

Felipe Amorim ◽

...

Keyword(s):

Circulation Pattern ◽

Tidal Energy ◽

Tidal Asymmetry ◽

Residual Circulation ◽

Linear Processes ◽

Bathymetric Data ◽

Full Analysis ◽

Bathymetric Map

<p>&#160;</p><p>The study is dedicated to the tidal dynamics in the Sylt-R&#248;m&#248; Bight with a focus on the non-linear processes. The FESOM-C model was used as the numerical tool, which works with triangular, rectangular or mixed grids and is equipped with a wetting/drying option. As the model&#8217;s success at resolving currents largely depends on the quality of the bathymetric data, we have created a new bathymetric map for an area based on recent studies of Lister Deep, Lister Ley, and the H&#248;jer and R&#248;m&#248; Deep areas. This new bathymetric product made it feasible to work with high resolution grids (up to 2 m in the wetting/drying zone). As a result, we were able to study the tidal energy transformation and the role of higher harmonics in the domain in detail. The tidal ellipses, maximum tidally-induced velocities, energy fluxes and residual circulation maps were constructed and analysed for the entire bight. Additionally, tidal asymmetry maps were introduced and constructed. The full analysis was performed on two grids with different structures and showed a convergence of the results as well as fulfillment of the energy balance. The tidal residual circulation and asymmetric tidal cycles largely define the circulation pattern, transport and accumulation of sediment and the distribution of bedforms in the bight, therefore the results are necessary and useful benchmarks for further studies in the area, including baroclinic and sediment dynamics investigations.</p>

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Non-linear model of the tides in the Gulf of Carpentaria

Marine and Freshwater Research ◽

10.1071/mf9810685 ◽

1981 ◽

Vol 32 (5) ◽

pp. 685 ◽

Cited By ~ 25

Author(s):

JA Church ◽

AMG Fobes

Keyword(s):

Open Boundary ◽

Open Boundary Conditions ◽

Kelvin Wave ◽

Rapid Phase ◽

North West ◽

The North ◽

Northern Half ◽

Non Linear ◽

Amphidromic Point ◽

Phase Variations

A non-linear barotropic model was used to evaluate the tidal regime in the Gulf of Carpentaria. The model was forced by open boundary conditions specified on a line joining Wessel Islands to False Cape and a volume flow through Torres Strait estimated from tidal constants on each side of the Strait. The model gives results in agreement with the available observations and in particular predicts mixed tides in the northern half of the Gulf and diurnal tides in the south-east corner of the Gulf. The diurnal tide consists of a Kelvin wave entering the Gulf in the north-west and propagating clockwise around the Gulf with one amphidromic point. The higher frequencies of the semidiurnal tides allow the generation of a first-mqde Poincare wave and the trapping of energy in the northern half of the Gulf. Amphidromes near Mornington Island and Groote Eylandt are also predicted, as is a region of low amplitude and rapid phase variations in the centre of the Gulf.

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The structure of non-linear processes

Tellus ◽

10.3402/tellusa.v25i6.9719 ◽

1973 ◽

Vol 25 (6) ◽

pp. 536-544 ◽

Cited By ~ 5

Author(s):

A. Quinet

Keyword(s):

Linear Processes ◽

Non Linear

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Impurity induced scale-free localization

Communications Physics ◽

10.1038/s42005-021-00547-x ◽

2021 ◽

Vol 4 (1) ◽

Author(s):

Linhu Li ◽

Ching Hua Lee ◽

Jiangbin Gong

Keyword(s):

Boundary Conditions ◽

Skin Effect ◽

Reciprocal Lattice ◽

Periodic Boundary Conditions ◽

Open Boundary ◽

Open Boundary Conditions ◽

Translational Invariance ◽

Scale Free ◽

Special Cases ◽

Simulation Results

AbstractNon-Hermitian systems have been shown to have a dramatic sensitivity to their boundary conditions. In particular, the non-Hermitian skin effect induces collective boundary localization upon turning off boundary coupling, a feature very distinct from that under periodic boundary conditions. Here we develop a full framework for non-Hermitian impurity physics in a non-reciprocal lattice, with periodic/open boundary conditions and even their interpolations being special cases across a whole range of boundary impurity strengths. We uncover steady states with scale-free localization along or even against the direction of non-reciprocity in various impurity strength regimes. Also present are Bloch-like states that survive albeit broken translational invariance. We further explore the co-existence of non-Hermitian skin effect and scale-free localization, where even qualitative aspects of the system’s spectrum can be extremely sensitive to impurity strength. Specific circuit setups are also proposed for experimentally detecting the scale-free accumulation, with simulation results confirming our main findings.

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