Abstract
The wave packet method, one form of the WKB technique, recently has
been employed to investigate the evolution of long planetary wave
packets in relation to the complex climate variability in the world
oceans. However, such a method becomes invalid near the caustics.
Here, the Lagrange manifold formalism is used to extend this
analysis to include the caustic regions. We conclude that even
though the wave packet method fails near the caustics, the
equations derived from this method away from caustics are identical
to ones from the Lagrange manifold formalism near caustics