Decadal variations of the southern hemisphere circulation

Abstract

A data set of monthly mean surface and sea-level pressure observations from a number of stations in the Southern Hemisphere (SH) for the period since 1901 has been used to investigate interannual and interdecadal variations of the SH circulation. A fairly uniform network of 62 stations was selected with data for the period 1955-1985, with a reduced network of 35 stations having data for the longer period 1901-1985. The sparse network has stations mainly on the SH tropical and mid-latitude land masses, with few islands or high-latitude stations. A rotated principal component analysis of the annual mean station pressure anomalies has been used to describe the dominant modes of interannual and ..