Ring Genesis and the Related Transports of Heat, Momentum and Vorticity: A Parameter Study

Abstract

The transport of heat, momentum and vorticity during the fife cycle of an unstable baroclinic wave that displays ring formation are investigated. Experiments have been carried out with a primitive equation numerical model. The evolution of sinusoidal disturbances superimposed on an eastward flowing jet is considered. The perturbations grow by means of the release of available potential energy until they ultimately develop into ring-like eddies. A two-layer approximation of the Gulf Stream in which the budgets and meridional transports are explored is the standard experiment. A parameter study estimates the dependency of the transport properties on the nondimensionalized environmental parameters that describe the linear stability of the flow. The initial available energy appears to be a controlling factor in the nonlinear behavior. Results in the nonlinear phase of the instability process qualitatively disagree with linear stability analysis when a parameter change is associated with an increase (decrease) in linear growth rate while the initial energy is not likewise increased (decreased); e.g. when b is varied. In all experiments the type of instability becomes more baroclinic during wave growth and all experiments display a net positive heat transport.