A Preliminary Investigation of a Relationship between South American Snow Cover and the Southern Oscillation

Abstract

A ten-year (1974–83) satellite record of snow cover is compared to a standard index of the Southern Oscillation. South American snow cover area during the May-October snow mean is found to be correlated significantly with the winter SOI values of the same year. The relationship is inverse; periods of low SOI values are associated with extensive South American snow cover while periods of high SOI values occur during years of diminished snow cover. The movements of the Pacific anticyclone and the midlatitude westerlies and subsequent changes in precipitation and temperature patterns are discussed in an analysis of this relationship.