An Aerological Study of Zonal Motion, its Perturbations and Break-down

TLDR

Rapid frontal waves over central Europe are analyzed in the context of a strong zonal current. The study examines how retrograde blocking influences the deepening of waves arriving from North America. The authors describe the progressive breakdown of the zonal flow by a retrograde blocking wave. Observations reveal that the longitudinal variation of the basic current pattern significantly contributes to the deepening of extra‑tropical wave cyclones, and the study supplies numerical values for key wave parameters.

Abstract

This paper contains an aerological analysis of a series of rapid-moving frontal waves associated with a well developed zonal current over central Europe. The gradual destruction of this zonal flow through a retrograde blocking ≥wave≤ is described. The relationship between the blocking process and the deepening of series of waves approaching the blocking zone from North America is discussed. The observational data and conclusions from this aerological study are presented for the purpose of rendering some assistance to theoreticians investigating atmospheric wave motions, by providing a few numerical values for certain characteristic parameters of these waves and by calling attention to a factor which appears to play a significant rôle in the deepening of certain types of extra-tropical wave cyclones, viz. the variation with longitude of the basic current pattern.