The reconstructed Indonesian warm pool sea surface temperatures from tree rings and corals: Linkages to Asian monsoon drought and El Niño–Southern Oscillation

Abstract

The west Pacific warm pool is the heat engine for the globe's climate system. Its vast moisture and heat exchange profoundly impact conditions in the tropics and higher latitudes. Here, September–November sea surface temperature (SST) variability is reconstructed for the warm pool region (15°S–5°N, 110–160°E) surrounding Indonesia using annually resolved teak ring width and coral δ18O records. The reconstruction dates from A.D. 1782–1992 and accounts for 52% of the SST variance over the most replicated period. Significant correlations are found with El Niño–Southern Oscillation (ENSO) and monsoon indices at interannual to decadal frequency bands. Negative reconstructed SST anomalies coincide with major volcanic eruptions, while other noteworthy extremes are at times synchronous with Indian and Indonesian monsoon drought, particularly during major warm ENSO episodes. While the reconstruction adds to the sparse network of proxy reconstructions available for the tropical Indo‐Pacific, additional proxies are needed to clarify how warm pool dynamics have interacted with global climate in past centuries to millennia.