Inter-annual variability of rainfalls in the Amazon basin and its vicinity

Abstract

An analysis of the rainfall series (12-month running means) of the 5° × 5° gridded data in the Amazon river basin and its vicinity (15° N – 20° S, 30° - 80° W) indicated that the rainfalls were highly variable both from year to year and from region to region. Correlations with even nearby regions hardly exceeded 0.50, though correlations were better (up to 0.70) in the regions near the eastern coast of Brazil. Moderate relationship with ENSO indices was obtained for the Amazon river basin and the regions to its north, and for NE Brazil, while moderate relationship with South Atlantic SST was obtained for NE Brazil and the region immediately to its west. All other relationships (with 30 hPa wind, North Atlantic Oscillation Index, etc.) were obscure.