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.

Long-term stationarity of El Niño–Southern Oscillation teleconnections in southeastern Australia

“…However, the 1836-1838 period stands out as a time of cold SSTs across the entire Indian Ocean, in response to a volcanic eruption in 1835 (Cole et al 2000;D'Arrigo et al 2006). This disagreement makes it difficult to determine the most likely IOD phase, or dominant Indian Ocean SST pattern that occurred between 1835 and 1850.…”

“…A reconstruction of SSTs in the eastern Indian Ocean (D'Arrigo et al 2006) suggests that the 1830s and 1840s was dominated by warm SSTs, indicative of negative IOD conditions which are conducive to above-average rainfall in southern SEA. However, the 1836-1838 period stands out as a time of cold SSTs across the entire Indian Ocean, in response to a volcanic eruption in 1835 (Cole et al 2000;D'Arrigo et al 2006).…”

Multiple tree-ring chronologies (ring width, δ13C and δ18O) reveal dry and rainy season signals of rainfall in Indonesia

“…We selected a site for isotope analyses previously reported to have a rather weak ring width climate signal (D'Arrigo et al, 2006b). The aim was to test if tree-ring stable isotopes reveal a better relationship to rainfall than ring widths.…”

ENSO flavors in a tree-ring δ<sup>18</sup>O record of <i>Tectona grandis</i> from Indonesia

“…Furthermore, several multi-proxy reconstructions of ENSO variability are available (e.g., Braganza et al, 2009;D'Arrigo et al, 2006;Emile-Geay et al, 2013;Mann et al, 2000;Wilson et al, 2010). However, many of these reconstructions are based on extratropical proxy records, particularly from tree-ring widths, and thus do not represent ENSO activity directly.…”