Abstract
Systematic studies of certain meridional cross sections carried out at the University of Chicago indicate that the westerlies in the upper troposphere and at the level of the tropopause often show a very narrow zone with extremely strong winds in the region above the frontal layer between the subtropical and the polar air. An example showing the method of analysis and its principal results is given. The stability of the strong westerly current (the “jet stream”) in this type of zonal air flow and the corresponding temperature distribution at the level of 200 mb are discussed.
