It has been suggested that both tropospheric and stratospheric jet streams are found in middle and high latitudes of the southern hemisphere (see WMO Technical Note No. 19). From temperature soundings it is known that a temperature maximum exists in the stratosphere over southern polar regions in the southern summer, being replaced by a minimum in March or April which intensifies until August, after which sudden warming takes place leading to a replacement of the temperature minimum by a temperature maximum in December. From this temperature distribution it is possible to infer that a westerly wind maximum will develop in the stratosphere in high southern latitudes in April and persist until November. No evidence has been found to support the suggestion that an easterly wind maximum may exist in the stratosphere at about latitude 75°S in January. It has been inferred (WMO Technical Note No. 19) that in addition to the sub-tropical westerly jet stream in the southern hemisphere, westerly jet streams occur in the troposphere between latitudes 40°S and 70°S. It seems likely that these are weakest in the southern summer but a r e well marked in other seasons. Observations from Macquarie Island, Wilkes, Amundsen -Scott and Australia have been examined and verify the existence of the stratospheric westerly wind maximum and the tropospheric middle and high latitude westerly jet streams. Stratospheric observations from southern Australia suggest that strong westerlies penetrated to these latitudes in winter at about 30 km. Some ideas concerning the mechanisms involved in the production of these jet streams are discussed.
W. J. Gibbs (Tue,) studied this question.