Impact of FGGE Buoy Data on Southern Hemisphere Analyses1

Abstract

Surface pressure observations from the First GARP Global Experiment (FGGE) drifting buoys, transmitted over the Global Telecommunication System, have been used in the Melbourne National Meteorological Analysis Centre (NMAC) operational analysis program since December 1978. From the beginning of the first Special Observing Period the network of buoys was sufficient to provide a data base over many areas from which routine surface observations have never previously been available. The great value of the new data in the specification of critical high latitude ridge axes, the true intensity of the Southern Ocean depressions and the westerly flow south of the Australian land mass is illustrated. It is shown that the 1979 analyses differ significantly from those of previous years, with regard to such features as the circumpolar trough, the middle latitude cyclonic systems and the sub-tropical highs. An appraisal of the differences indicates they are not only due to the characteristics of the 1979 circulation but also to a first delineation of the hemispheric circulation features by use of the FGGE data base.