Propagating decadal sea surface temperature signal identified in modern proxy records of the tropical Pacific

Analysis of 86years of multiple modern coral δ¹⁸O records in the tropical Pacific reveals a basin-scale decadal pattern of variability. Although coral δ¹⁸O records the effects of both temperature and seawater δ¹⁸O variability due to salinity effects, in practice, most of the records used here agree well with observations of sea surface temperature on longer timescales. These coral proxy records reveal strong variability near a 12-year period. Their relative phasing suggests a signal propagating from the southwestern subtropical Pacific to other regions. The results are consistent with recent studies based on instrumental data and with coupled climate model studies, in which advection of thermal anomalies leads to El Niño/Southern Oscillation-like variability on decadal timescales. Additionally, there is evidence for a significant shift in many of the time series, along with a decrease in the decadal variability, occurring in the early 1940s. Finally, the proxy records indicate the presence of strong teleconnections between the eastern tropical Pacific and high latitude climate.