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

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.