Reconstructing the South Pacific Convergence Zone Position during the Presatellite Era: A La Niña Case Study

AbstractSixty-four southwest Pacific island meteorological stations were used to develop ENSO-related austral warm season (November–April) rainfall climatologies for 1961–90. Historical data for the same station set were then examined for 1955/56, one of the strongest La Ninas of the twentieth century. The pattern for that event was typical of a well-coupled protracted La Nina, with above-normal rainfall (>150%) observed for 17 stations in the case study.Tropical cyclone tracks were also used to illustrate the proximal effects of historical storms on station rainfall. Several stations that were located along the northern edge of the tropical cyclone swarm, but south of a region of anomalously low rainfall, were selected as possible candidates having been close to the mean South Pacific convergence zone (SPCZ) location. Linear interpolations between those stations highlighted a likely SPCZ position for the 1955/56 event.The reconstructed SPCZ location indicated a position southwest of normal, consistent wi...