Interannual-to-interdecadal sea surface temperature variability along the western coast of South America

Abstract

Interannual and interdecadal regional-scale sea surface temperature (SST) variability along Peru and Chile are described based on 9 coastal stations and global SST in the period 1951-1999. ENSO-related interannual variability dominates the low-passed time series along the coast, with maximum amplitudes in the tropics decreasing southward. At tropical latitudes interdecadal variance is about one-third of the interannual variance while they are of similar amplitude in the midlatitudes (36°S). The correlation between the low frequency coastal modes and the Pacific and Atlantic SST suggests that the coastal SST variability comprises two main large-scale climate processes: the ENSO cycle at interannual timescale, and a basin-wide, perhaps even a global-scale, interdecadal oscillation.