The Amplification of Height Wave 1 in January 1979: A Characteristic Precondition for the Major Warming in February

Abstract

The development in time and space of the planetary-scale height waves 1 and 2 and of the mean zonal flow is described for the winter 1978/79. It is concluded that this winter supports earlier observational results: the anomalous amplification of height wave 1 in the stratosphere concurrent with a distinct minimum of height wave 2 is a characteristic precondition for the development of a major warming. If, later, the breakdown itself concurs with the development of height wave 2, the amplification of height wave 1 before is needed insofar as it changes the zonal flow, i.e., displaces the stratospheric jet poleward, to favor propagation of height wave 2.