Vanuatu fossil coral SST reconstruction for 4200 yr BP

We present a 47-year-long record of sea surface temperature (SST) derived from Sr/Ca and U/Ca analysis of a massive Porites coral which grew at ~4150 calendar years before present (B.P.) in Vanuatu (southwest tropical Pacific Ocean). Mean SST is similar in both the modern instrumental record and paleorecord, and both exhibit El Niño-Southern Oscillation (ENSO) frequency SST oscillations. However, several strong decadal-frequency cooling events and a marked modulation of the seasonal SST cycle, with power at both ENSO and decadal frequencies, are observed in the paleorecord, which are unprecedented in the modern record.

本研究报道了一段长达47年的海表温度（sea surface temperature, SST）记录，该记录通过对一块生长于瓦努阿图（热带西南太平洋）、距今约4150年（calendar years before present, B.P.）的块状滨珊瑚（Porites）的锶钙比（Sr/Ca）与铀钙比（U/Ca）分析获取。现代仪器观测记录与该古气候记录的平均海表温度基本一致，二者均呈现出受厄尔尼诺-南方涛动（El Niño-Southern Oscillation, ENSO）频率调控的海表温度振荡特征。然而，该古气候记录中观测到若干显著的十年尺度降温事件，以及海表温度季节循环的显著调制现象——其功率谱同时涵盖ENSO与十年尺度频率分量，这类现象在现代观测记录中前所未见。