Resonant excitation of coastal Kelvin waves by free inertia–gravity waves impinging on the coast is studied in the framework of the simplest baroclinic model: two-layer rotating shallow water with an idealized straight coast. It is shown that, with respect to the previous results obtained with the one-layer model, new resonances leading to a possible excitation of Kelvin waves appear. The most ...

We employ a three-dimensional hydrodynamic model (COHERENS) in a fully prognostic mode to study the circulation and water mass properties of the Persian Gulf – a large inverse estuary. Our findings, which are in good agreement with observational evidence, suggest that the Persian Gulf experiences a distinct seasonal cycle in which a gulfwide cyclonic overturning circulation establishes in sprin...

[1] Temperature, salinity, velocity, and wind from a mooring at 0 N, 23 Ware used along with satellite data for sea surface temperature and sea level to examine the contribution of tropical instability waves (TIWs) to the energy and heat balance of the equatorial Atlantic mixed layer. The TIWs appear as periodic 20–30 day fluctuations of currents, temperature, and salinity, which intensify begi...

Turbulent fluids are frequently observed to spontaneously self-organize into large spatial-scale jets; geophysical examples of this phenomenon include the Jovian banded winds and the earth’s polar-front jet. These relatively steady large-scale jets arise from and are maintained by the smaller spatialand temporalscale turbulence with which they coexist. Frequently these jets are found to be adju...

Nonlinear quasigeostrophic flows in two layers over a topographic slope are considered. Scaling the lower layer potential vorticity equation yields two parameters which indicate the degree of nonlinearity in the lower layer. The first, u' (the strength of the deep flow divided by the product of the effective bottom slope and the squared length scale), is related to the advection of relative vor...

In this thesis, the influence of boundary layer processes and seasonal forcing on baroclinic eddy equilibration is studied to understand how the baroclinic adjustment is modified when taking into account these two factors. A modified β plane multilevel quasi-geostrophic (QG) model with an interactive stratification and a simplified parameterization of atmospheric boundary layer physics is used ...

It has been proposed that the impact of moisture on atmospheric eddy circulations can be approximated using a reduced effective stratification defined in terms of a parameter λ, which quantifies the asymmetry between upward and downward motions. Here λ is analyzed for the midlatitude regime using baroclinic lifecycles computed with the Weather Research and Forecast model. Vertical velocities ar...

The downstream development in both space and time of baroclinic instability is studied in a nonlinear channel model on the f -plane. The model allows the development of the instability to be expressed on space and time scales that are long compared to the growth rates and wavelengths of the most unstable wave. The unstable system is forced by time-varying boundary conditions at the origin of th...

The bifurcation diagram of a truncation to six degrees of freedom of the equations for quasi-geostrophic, baroclinic ow is investigated. Period doubling cascades and Shil'nikov bifurcations lead to chaos in this model. The low dimension of the chaotic attractor suggests the possibility to reduce the model to three degrees of freedom. In a physically comprehensible limit of the parameters this r...

1 Large-scale variability in the Northern Hemisphere (NH) circulation can be 2 viewed in the context of three primary types of structures: 1) teleconnection patterns; 2) 3 a barotropic annular mode; and 3) a baroclinic annular mode. The barotropic annular 4 mode corresponds to the northern annular mode (NAM) and has been examined 5 extensively in previous research. Here we examine the spatial s...