Structure of the upper westerlies; a study of the wind field in the eastern Atlantic and western Europe in September 1950

✍ Scribed by R. Murray; D. H. Johnson

• Publisher: John Wiley and Sons
• Year: 1952
• Tongue: English
• Weight: 786 KB
• Volume: 78
• Category: Article
• ISSN: 0035-9009
• DOI: 10.1002/qj.49707833607

✦ Synopsis

Abstract

On the basis of 60 cross‐sections over western Europe and the northeast Atlantic, two for each day of September 1950, it is concluded that:

Daily charts are given showing the jet axes and intensities at 300 mb superimposed on the surface analysis.

The westerlies always contain one or more wind maxima in the upper troposphere with structure broadly similar to that described by other writers on jet streams but with much variety of intensity and velocity profile.

The mean horizontal wind shear on the warm side of the jet stream is about two‐thirds of that on the cold side where it averages 20 kt/100 mi and may exceed 100 kt/100 mi.

The geostrophic relation gives a broadly correct representation of the true winds.

There is a broad connexion between fronts and jet streams, but the relationship is often less simple than that suggested in published work hitherto. Divided jets, distinct double jets and other complexities arise.