Sea surface temperature anomalies for Pliocene interglacial KM5c (PlioVAR)

We examine a single interglacial during the late Pliocene (KM5c, ca. 3.205 +/- 0.01 Ma) when atmospheric CO2 concentrations were higher than pre-industrial, but similar to today and to the lowest emission scenarios for this century. As orbital forcing and continental configurations were also similar to today, we are able to focus on equilibrium climate system response to modern and near-future CO2. We have synthesised largely published datasets, scrutinised their age models, and generated mean absolute SSTs and their anomaly relative to the pre-industrial. Here we present those values for both alkenone and foraminifera-Mg/Ca proxies.

本研究针对上新世晚期的KM5c间冰期展开分析，该地质年代约为3.205±0.01百万年（Ma）。此时期大气二氧化碳浓度高于工业革命前水平，与当前浓度及本世纪最低碳排放情景相当。鉴于轨道强迫与大陆构型均与现今相近，我们得以聚焦气候系统对现代及近未来二氧化碳浓度的平衡响应。本研究综合了大量已发表的数据集，严格核查了各数据集的年代模型，并计算得到绝对平均海表温度（Sea Surface Temperature, SST）及其相对于工业革命前的温度距平。本文呈现了烯酮类（alkenone）与有孔虫镁钙比代用指标（foraminifera-Mg/Ca proxy）对应的上述数值。