Nonlinear Processes in Geophysical Fluid Dynamics -

. .

Résumé :
Thisvolumecontainsacollectionofpapersbyinternationalexpertsingeoph- ical ?uid dynamics, based upon presentations at a colloquium held in memory of Pedro Ripa on the ?rst anniversary of his untimely death. They review or present recent developments in hydrodynamic stability theory, Hamiltonian ?uid mechanics,balanceddynamics, waves,vortices,generaloceanographyand the physical oceanography of the Gulf ofCalifornia; all of them subjects in which Professor Ripamadeimportant contributions. His work, but also his friendly spiritandkindnesswerehighly regardedandappreciatedby colleagues and students alike around the world. This book is a tribute to his scienti?c legacy and constitutes a valuable reference for researchers and graduate s- dents interested in geophysical and general ?uid mechanics. Earlyin his career asa physicaloceanographer,Pedro Ripa made two la- mark contributions to geophysical ?uid dynamics. In 1981, he showed that the conservation of the potential vorticity is related to the invariance of the eq- tions of motion under the symmetry transformationsof the labels that identify the ?uid particles. That is, potential vorticity conservation is a consequence, via Noether?s theorem, of the particle re-labelling symmetry. Two years later he published a paper entitled ?General stability conditions for zonal ?ows in a one-layer model on the beta-plane or the sphere?, where he established nec- sary conditions for stability in the shallow water equations, nowadays known as ?Rip?s Theorem. ? This is one of the very few Arnol?d-like stability con- tions that goes beyond two-dimensional or quasi-geostrophic ?ow, and stands alongside other famous stability criteria in making the foundations of the ?eld.

Sommaire:
1 Ripa's Theorem and its Relatives.- 2 Deep Ocean Influence on Upper Ocean Baroclinic Instability Saturation.- 3 Constrained-Hamiltonian Shallow-Water Dynamics on the Sphere.- 4 Hamiltonian Description of Fluid and Plasma Systems with Continuous Spectra.- Stable Vortices as Maximum or Minimum Energy Flows.- 6 Nonlinear Outflows on a ? Plane.- 7 Generation of Internal Gravity Waves by Unstable Overflows.- 8 On the Effect of Heat and Fresh-Water Fluxes Across the Ocean Surface, in Volume-Conserving and Mass-Conserving Models.- 9 Baroclinic Waves in Climates of the Earth's Past.- 10 Mean and Eddy Dynamics of the Main Thermocline.- 11 An Overview of the Physical Oceanography of the Gulf of California.- 12 The Atmosphere over the Gulf of California.- 13 Residual Flow and Mixing in the Large-Islands Region of the Central Gulf of California.- 14 A Description of Geostrophic Gyres in the Southern Gulf of California.- 15 Nonlinear Internal Waves Near Mexico's Central Pacific Coast.- 16 CANEK: Measuring Transport in the Yucatan Channel.- 17 Diagnostic Force Balance and its Limits.- 18 A Note on the Effects of Solid Boundaries on Confined Decaying 2D Turbulence.- 19 Effects of Rotation on Convective Instability.- 20 Advection by Interacting Vortices on a ? Plane.- 21 A Low-Dimensional Dynamical System for Tripole Formation.