No full-text available
To read the full-text of this research,
you can request a copy directly from the authors.
A two-dimensional numerical model of tidal motions on the shelf of Guinea
Abstract
The general statement of a non-linear problem in modelling a barotropic tide for the limited part of a real shelf and the problems related to artificial division of the computation area in the ocean by a ‘liquid’ boundary are considered. Linear combinations of various types of boundary conditions and analytical expressions are used to describe the tidal wave structure at the ‘liquid’ boundaries. The results of test computations for basins with the simplest outlines are given. The model is used to reconstruct the spatial distribution of characteristics of theM
2 tide on the shelf of Guinea. The methods of computation and specification of unambiguously determined model parameters are described. Joint analysis of the modelling results and the field data has been carried out. The tidal map of theM
2 wave is plotted for the area under investigation.
ResearchGate has not been able to resolve any citations for this publication.
Ocean tide information can solve vital problems in oceanology and geophysics. Elastic properties of the Earth's crust, tidal gravity variations and deviations in trajectories of artificial satellites can be studied from the dynamics of ocean tides. This book contains mathematical models and applications on several problems related to ocean tide dynamics. The first part serves as an introduction to studies of tidal dynamics equations and the application in experimental studies. Specific problems like free oscillations and forced tidal oscillations in the oceans and the ocean-shelf system are discussed. The book deals with tidal flow in the bottom boundary layer. Data and models are presented and experimental and theoretical results are compared.
The tidal regime west of Vancouver Island was simulated using a nonlinear barotropic two dimensional tidal model using realistic bathymetry. The model underestimated the wavelength of the continental shelf wave, due to the neglect of stratification and the influence of mean flows. A further model was used to investigate the influence of mean currents on the tidal regime.
The formulation of open boundary conditions to apply at the mouth of a reduced gravity model of a bay are described. The objective was to calculate the response of the bay to wind forcing over the bay itself, without considering the influence of regions beyond. It is shown that open boundaries from which Kelvin waves can propagate along the coast into the model domain must be treated with care. The use of sponge layers rather than radiation conditions is described. Application of results to three-dimensional general circulation type models are discussed. (from authors' abstract)
We have determined the energetic and spatial characteristics of baroclinic and barotropic tidal semi-diurnal fluctuations using the current temperature and velocity data collected by 12 self-contained buoy stations (SCBS) near the shelf of the Republic of Guinea at depths ranging from 50 to 1000 m. Intensive baroclinic motion was observed to prevail near the bottom within the depth range 100–1000 m. The energy of long waves largely propagated from the bottom to the surface, whereas the energy of short waves was transferred in the opposite direction.
Attention is focused on the use of numerical formulations of the Sommerfeld radiation condition δΦ/δt + cδΦ/δx = 0 as a lateral boundary condition. This numerical boundary condition which originally used the leap frog scheme (Orlanski 1976) is shown to be made more accurate by the use of the upstream method. In this form it is tested in a two-dimensional model of a density current and is stable. the boundary becomes effectively transparent to incident disturbances, even under the severe test of allowing the density current head to propagate upstream and through the boundary, thus changing initial inflow to strong outflow.
An analysis is presented of various extrapolation and radiation boundary conditions, involving calculation of their accuracy for waves and more general solutions. the leading terms in the truncation error are compared, and for general disturbances some have second order accuracy, while for solutions of the wave equation, it is shown that the radiation condition is third order. It can be made fourth order, for both leapfrog and upstream differencing, by the use of an extrapolation formula to give a better numerical estimate for c. This condition derives its greater accuracy from the use of values at seven (space and time) gridpoints, in contrast to the original scheme which used four, and standard extrapolation formulae which use, at most, three points.
Outflow radiation conditions have frequently been used at open boundaries in oceanography and meteorology. A new implementation of Orlanski's formulation for problems requiring a radiation open boundary has been developed. Three different cases in which Rossby and Kelvin waves are present are studied. In all these tests the proposed open boundary condition shows no reflection at the outflow of the Kelvin wave. However, some reflection at the outflow of the Rossby wave is observed.
A review of recent developments in the study of ocean tides and related phenomena is presented. Topics briefly discussed include: the mechanism by which tidal dissipation occurs; continental shelf, marginal sea, and baroclinic tides; estimation of the amount of energy stored in the tide; the distribution of energy over the ocean; the resonant frequencies and Q factors of oceanic normal modes; the relationship of earth tides and ocean tides; and numerical global tidal models.
Tides in the Atlantic Ocean
- K T Bogdanov
- B V Kharkov
- Dang Kong Min
- K. T. Bogdanov
Features of tidal motions on the Guinean shelf
- Goryachkin
- N Yu
- V A Ivanov
Mathematical modelling of long waves in the coastal zone. In:Theoretical and Experimental Study of Long-Wave Processes
- M T Gladyshev
A. treatment of open boundary conditions in shallow water equations.Finite Elem
- T Kodana
- M Kaneko
- M Kawakara
The Shallow-Water Theory. Oceanological Problems and Numerical Methods
- N Voltsinger
- Ya
- R V Pyakovsky
Long-Wave Dynamics of the Coastal Zone
- N Voltsinger
- Ya
- K A Klevannyi
- E N Pelinovsky
- N. Ya. Voltsinger
On the boundary problems for the set of equations of St. Venan at the plane
- V F Baklanovskaya
- V B Paltsev
- I I Chechel
- V. F. Baklanovskaya
Waves in Boundary Oceanic Areas
- V V Efimov
A Differential System Theory
- A A Samarsky
- A. A. Samarsky
Cartes des lignes cotidals dans les oceans
- C Villian
- C. Villian
Tidal Waves in Outlying Seas
- A V Nekrasov
- A. V. Nekrasov
On kinematic analysis of tides
- V V Timonov
- V. V. Timonov
The Shallow-Water Theory
- N Voltsinger
- Ya
- R V Pyakovsky
- N. Ya. Voltsinger
On the formulation of an open boundary at the mouth of a bay
- R T Geatbatch
- T Otterson
- R. T. Geatbatch
Mathematical modelling of long waves in the coastal zone
- M T Gladyshev
- M. T. Gladyshev
Numerical solution of the problem on propagation of semi-diurnal tidal waves (M 2 andS 2) in the world's oceans
- K T Bogdanov
- V A Magarik
- K. T. Bogdanov
Features of tidal motions on the Guinean shelf
- Yu N Goryachkin
- V A Ivanov
- Yu. N. Goryachkin