Hybrid Rossby-shelf modes in a laboratory ocean
نویسندگان
چکیده
Idealized laboratory experiments reveal the existence of forced dissipative hybrid Rossby shelf modes. The laboratory ocean consists of a deeper ocean, accommodating basin scale Rossby modes, and a coastal step shelf, accommodating trapped shelf modes. Planetary Rossby modes are mimicked in the laboratory via a uniform topographic slope in the North-South direction. Hybrid modes are found as linear modes in numerical calculations and similar streamfunction patterns exist in streak photography of the rotating tank experiments. These numerical calculations are based on depth-averaged potential vorticity dynamics with Ekman forcing and damping. Preliminary nonlinear calculations explore the deficiencies observed between reality and the linear solutions. The aim of the work is twofold: to show that idealized hybrid Rossby shelf modes exist in laboratory experiments, and to contribute in a general sense to the discussion on the coupling and energy exchange associated with hybrid modes between shallow coastal seas and deep ocean basins.
منابع مشابه
On the scattering of baroclinic Rossby waves by a ridge in a continuously stratified ocean
In global ocean dynamics Rossby waves play a vital rôle in the long-term distribution of vorticity; knowledge of the interaction between these waves and topography is crucial to a full understanding of this process, and hence to the transportation of energy, mixing and ocean circulation. The interaction of baroclinic Rossby waves with abrupt topography is the focus of this study. In this paper ...
متن کاملCoupling coefficients and kinetic equation for Rossby waves in multi-layer ocean
The kinetic description of baroclinic Rossby waves in multi-layer model ocean is analysed. Explicit analytical expressions for the coupling coefficients describing energy exchange intensity between different modes are obtained and their main properties are established for the threelayer model. It is demonstrated that several types of interactions vanish in the case of simple vertical structures...
متن کاملA Semi-Implicit Semi-Lagrangian Finite-Element Shallow-Water Ocean Model
The nite-element, semi-implicit, and semi-Lagrangian methods are combined together to solve the shallow-water equations using unstructured triangular meshes. Triangular nite elements are attractive for ocean modeling because of their exibility for representing irregular boundaries and for local mesh re nement. A \kriging" interpolator is used for the semi-Lagrangian advection, leading to an acc...
متن کاملA Model of Decadal Middle-Latitude Atmosphere–Ocean Coupled Modes
An analytical model of the mutual interaction of the middle-latitude atmosphere and ocean is formulated and studied. The model is found to support coupled modes in which oceanic baroclinic Rossby waves of decadal period grow through positive coupled feedback between the thermal forcing of the atmosphere induced by SST anomalies and the resulting wind stress forcing of the ocean. Growth only occ...
متن کاملDecadal Variability of the Kuroshio Extension: Observations and an Eddy-Resolving Model Hindcast*
Low-frequency variability of the Kuroshio Extension (KE) is studied using observations and a multidecadal (1950–2003) hindcast by a high-resolution (0.1°), eddy-resolving, global ocean general circulation model for the Earth Simulator (OFES). In both the OFES hindcast and satellite altimeter observations, low-frequency sea surface height (SSH) variability in the North Pacific is high near the K...
متن کامل