On the behaviour of baroclinic waves undergoing horizontal deformation. II: Error‐blund amplification and Rossy wave diagnostics

Abstract

An expression for the maximum possible amplification of a baroclinic wave with zero potential vorticity, undergoing horizontal deformation, is obtained. This amplification provides an estimate of the growth of hypothetical analysis errors for such a system. For the geophysically relevant flows considered in detail in this paper, strain rates of ±1 × 10−5 s−1 cause a 28% reduction in the logarithmic amplification over a 48‐hour period. If the effects of phase changes of water are simulated by halving the brunt‐Väisälä frequency, all growth rates are larger, but strain rated of ±1 × 10−5s−1 now cause a 34% reduction logarithmic amplification. Notably, this corresponds to an 81% reduction in ac..