GEOPHYSICAL MONOGRAPH SERIES, VOL. 7, PP. 128-148, 1962
Mean westerly jet streams in the southern hemisphere
International Antarctic Analysis Center, Bureau of Meteorology, Melbourne, Australia
Meridional cross-section diagrams of temperature and zonal wind have been constructed. Some diagrams have been drawn for selected
days in September 1959 and January 1960 extending along a meridian through eastern Australia, south of 25°S to the south pole,
to show the temperature and zonal wind distribution between 500 and 50 mb; other diagrams show mean monthly cross sections
for July 1959, October 1959, January 1960 and April 1960 drawn along three meridians through (i) eastern Australia, (ii) South
Africa, and (iii) South America, again to show the temperature and zonal wind profiles from latitude 25°S to the south pole,
between 500 and 50 mb; and a third set has been drawn for selected days in 1960 extending along a meridian through eastern
Australia south of 30°S to the south pole, to show the zonal wind distribution up to the 30-km level.
The thermal wind equation has been used to derive wind values where direct measurements are lacking. It is established that two westerly wind maxima may be found simultaneously on a given meridian. It is also shown that in all seasons except summer a mean wind maximum having jet stream characteristics can be found between 25 and 35°S near the 200-mb level with speed ranging from 50 to 85 kt; whilst another westerly wind maximum may be found between 40 and 60°S throughout the whole year. The high latitude westerly wind maximum has jet stream characteristics only in summer and autumn; in winter and spring it is found to be portion of a broad westerly circumpolar current similar to that suggested by Murgatroyd, although the mean speed, exceeding 200 kt at 30 km, is very much greater than that so far depicted for the northern hemisphere winter.
Citation: Phillpot, H. R. (1962), Mean westerly jet streams in the southern hemisphere, in Antarctic Research: The Matthew Fontaine Maury Memorial Symposium, Geophys. Monogr. Ser., vol. 7, edited by