Aspects of wave behaviour in the mid‐ and upper troposphere of the southern Hemisphere |
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| Authors: | Kevin Hamilton |
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| Institution: | 1. National Center for Atmospheric Research , Boulder, Colorado;2. Department of Oceanography , University of British Columbia , Vancouver, B.C. |
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| Abstract: | Abstract The zonal wavenumber spectra of the geopotential heights of the 300‐ and 500‐mb surfaces in the Southern Hemisphere were determined for each month between May 1972 and November 1979 using daily operational analyses produced by the Australian Bureau of Meteorology. During over one‐quarter of the “summer” months (November through March) there are very prominent peaks at zonal wavenumber five in the region of the mid‐latitude jet (～35–60°S). Frequently wavenumber five totally dominates the eddy fields in individual daily maps so that height contours in mid‐latitudes take on virtually pentagonal shapes. During periods when wavenumber 5 is prominent, it is observed to propagate eastward in a very regular manner with a period of about eleven days. All these findings are consistent with Salby's (1982) earlier results concerning the Southern Hemisphere height fields during the first few months of the FGGE experiment. There is little evidence for a similar phenomenon in the winter circulation of the Southern Hemisphere. |
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