Instability of a two-layer baroclinic flow in a channel

Abstract

The properties of the two-layer model for disturbances of a rotating baroclinic basic state have been investigated extensively over the last few decades by application of numerical and analytical techniques. Many of the studies, e.g., Pedlosky (1964a, b) and Drazin (1970), have assumed the presence of vertical sidewalls in the analysis for the purpose of supplying horizontal boundary conditions for the eigenfunction representing the disturbance. While Hart (1972) has considered in detail the linear and finite amplitude nature of baroclinic waves in a cylindrical tank, to the author's knowledge no experimental two-layer study which includes horizontal confinement has been presented in the literature. The present investigation uses the channel model as a basis for studying the stability of the axisymmetric regime over a wide range of reciprocal Burger number ( F ) and Rossby number ( Ro ) which represent a measure of the rotation rate of the system and the vertical shear of the axisymmetric regime respectively. The results are assessed using a linear theory which assumes a simple axisymmetric basic state. Additionally they are compared to Pedlosky's analysis (196413) which considers the effects of horizontal shear on the stability of the basic state. DOI: 10.1111/j.2153-3490.1978.tb00862.x