Patterns of Climatic Variation in Argentina and Chile—I Precipitation, 1931–60

Abstract

In order to gain an understanding of the spatial connections and representativeness of instrumental and proxy climatic data from particular sites, a 30-year data set for a network of 87 stations in Argentina and Chile has been analyzed. In this paper the results for precipitation are presented. These show three dominant patterns of year-to-year variability which together account for more than 40% of the total variance. Two methods have been used to show how these patterns are linked to variations in the general circulation. Significant correlations are found between precipitation variations and fluctuations in each of four indices of the general circulation: an index of the Southern Oscillation; an index of the pressure difference across the Antarctic between Tasmania and the Falkland Islands region., the latitude of the high-pressure belt off the coast of Chile; and an index of the pressure difference across the tropical Atlantic Ocean. An unexpected link is found between the pressure fluctuations in the tropical Atlantic and the midlatitude circulation.