ISSN:0309-1929    

DOI:10.1080/03091927808242637

出版商:Taylor & Francis Group    

年代:1978

数据来源: Taylor

摘要:

New rates of decay are presented for temporally-attenuated gravity waves in deep water, allowance being made for the energy dissipated in the Stokes interfacial boundary layer in the air. This decay-rate, involving air drag, may then be used to deduce a new “free-surface” boundary condition for the problem of the mass transport velocity due to progressive waves; for shallow-water waves, two specific velocity profiles are calculated, and indicate large differences in comparison with the corresponding profiles of Longuet-Higgins (1953) for a vacuum-water interface.

ISSN:0309-1929    

DOI:10.1080/03091927808242638

出版商:Taylor & Francis Group    

年代:1978

数据来源: Taylor

摘要:

In a rotating-table investigation of the resonance of shelf waves around islands, partial radial barriers are found to lower the resonant frequencies somewhat, to increase dissipation, and to change the relative modal response; but not to destroy the resonance. Thus geometrically simple computational models may be adequate for the calculation of such resonant frequencies for real islands, and more complicated models may not be necessary, for the lowest modes at least.

ISSN:0309-1929    

DOI:10.1080/03091927808242639

出版商:Taylor & Francis Group    

年代:1978

数据来源: Taylor

摘要:

The asymptotic consequences due to mixing by an oscillating bottom mixer in a stably stratified fluid in a container are analyzed theoretically. This mixed region is found to move laterally away from the mixer along its neutral buoyancy level in the form of a horizontal wedge. With the beginning of a rather arbitrary initial configuration. the two-dimensional wedge is found always to approach a parabolic profile associated with which the mixed region flow is horizontally columnar. Horizontal pressure gradient generated from density differences across the interface pushes the unmixed fluid towards the wall of the container. causing a return flow in free shear layers along levels marked by the top and bottom of the mixer. The lateral speed of the tip of the mixed fluid is found to be proportional to the square of the Brunt-Väisäla frequency. and the fourth power of the mixed region and inversely proportional to the vertical eddy viscosity of the mixed fluid. Qualitative verification of the theory is achieved with a simple laboratory model experiment.

ISSN:0309-1929    

DOI:10.1080/03091927808242640

出版商:Taylor & Francis Group    

年代:1978

数据来源: Taylor

摘要:

The generation of eddies by a large-scale flow over mesoscale topography is studied with the help of two- and three-layer nonlinear quasi-geostrophic models of the open ocean. The equations are integrated forward in time with no eddies present initially. For a given time, the displacement of the interface between layers two and three (ζ) tends to a well-defined limit (function of the horizontal spatial coordinates) asρ3- ρ2→0(ρris the density of layerr). Even for values of α[= (ρ3-ρ2)/(ρ2-ρ1)]assmall as 0.01 the potential energy due to ζ is not negligible and it can reach, in some cases, a considerable fraction of the total eddy energy.

ISSN:0309-1929    

DOI:10.1080/03091927808242641

出版商:Taylor & Francis Group    

年代:1978

数据来源: Taylor

摘要:

The propagation properties of hydromagnetic-inertial-gravity waves in a Boussinesq fluid are studied for two representative models. One model is characterised by horizontal rotation, magnetic field and flow, the magnetic field and flow being perpendicular and vertically sheared. In the other model both magnetic field and rotation are vertical and uniform but the flow is horizontal and latitudinally sheared. In a slowly varying shear, when the WKBJ approximation is applicable, the wave normal surfaces for different values of magnetic field and flow are used to construct the various types of ray trajectories. In a full wave treatment, in which variations in the basic state are taken into account, it is found that the total wave energy flux (or the wave action flux), 𝒜, in the direction of the shear is constant except at critical layers (i.e. singularities predicted by the WKBJ treatment), where it jumps from one constant value to another. The invariance of 𝒜 is used to show that MAC-waves can be over-reflected by a finite shear layer free of critical layers. By adopting the correct matching procedure across critical layers the influence of hydromagnetic critical layers on the reflexion of hydromagnetic-inertial-gravity waves by finite shear layers is investigated. It is found that such critical layers can facilitate over-reflexion by “emitting” energy flux.

ISSN:0309-1929    

DOI:10.1080/03091927808242642

出版商:Taylor & Francis Group    

年代:1978

数据来源: Taylor

摘要:

Generalizing the results obtained by Stix (1970) and by Whitehead (1971), we present the homogeneous boundary conditions that are imposed by a fluid of stable but otherwise arbitrary stratification. These penetrative conditions are strictly valid only in the limit of steady linearized flow, but under some conditions they can also be applied to nonlinear problems. An example of linear penetrative convection is treated in order to illustrate the use of these boundary conditions.

ISSN:0309-1929    

DOI:10.1080/03091927808242643

出版商:Taylor & Francis Group    

年代:1978

数据来源: Taylor

摘要:

This work describes the development of a diagnostic model designed to deduce characteristics of the mean circulation of a portion of the upper atmosphere of Venus. The model will use remotely sensed, global scale temperatures and solves momentum and mass flux equations. The solutions are dependent on externally specified, and inexactly known parameters.

ISSN:0309-1929    

DOI:10.1080/03091927808242644

出版商:Taylor & Francis Group    

年代:1978

数据来源: Taylor

摘要:

By H. K. Moffatt. Cambridge University Press1978. 343 pp., £15.50, ISBN 0521 216400.

ISSN:0309-1929    

DOI:10.1080/03091927808242645

出版商:Taylor & Francis Group    

年代:1978

数据来源: Taylor

ISSN:0309-1929    

DOI:10.1080/03091927808242646

出版商:Taylor & Francis Group    

年代:1978

数据来源: Taylor