Pulse asymptotics of three-dimensional baroclinic waves

Abstract

The asymptotic development at large time of waves arising from localized disturbances in a baroclinic flow is examined. Vertical structures unlike those associated with the more commonly examined temporal normal modes are found both for the pulse confined to a channel as previously examined, and for the unconfined pulse on an infinite beta-plane. These structures and their implied transports are compared to observations in the regions of storm tracks. It is also found that the meridional extent of the asymptotic solution becomes large compared to observed cyclone wavetrains, emphasizing the importance of flow inhomogeneity and sphericity effects in determining the latitudinal structure of eddies.