Isolated anomalies in westerly jet streams: a unified approach

Abstract

A weakly nonlinear theory describes how nonlinearity can balance dispersion effects for both split jet stream anomalies (which resemble blocking flows) and for jet intensification anomalies. It is shown that the variation of the potential or refractive-index function Λ ≡ dq/dψ across the jet stream is crucial for determining which types of anomaly will tend to persist. Some discussion and investigation of the possible role of critical lines in preventing dispersion into equatorial latitudes is also presented. Finally, the possibility of testing this theory by making appropriate diagnostic measurements is considered. -from Authors