Southern hemisphere general circulation and its variability
Some aspects of the variability of the atmospheric general circulation in the Southern Hemisphere, with emphasis on 500 mb, are discussed. Long term trends in the circulation between 1956-66 and 1972-78 are fairly barotropic in structure and consists of substantial height increases over Antarctica and the subtropical oceans, and height falls over the other continents. Interannual variations are also pronounced and show a quasi-biennial fluctuation in the zonal mean fields with a systematic progression of anomalies from low to high latitudes. This pattern is strongest and most consistent in the Australia-New Zealand region and may provide a basis for making long range circulation and weather forecasts on the time scale of three to six months.