Box models for 2D geometry

Box models have been successfully used in the investigation of some problems of homogeneous ambients, as discussed in Chapter 4. Here we extend these models to the current in a linearly-stratified ambient. Our main concern will be with the S = 1 intrusion-like configuration with changing volume V = qtα, which will be considered in § 17.2; this has some simple analytical solution and is of practical importance.