Ocean Sciences Department, University of California, Santa Cruz, CA 95064, USA. Biology and Paleo Environment, Lamont-Doherty Earth Observatory, Palisades, NY 10964, USA.
Ocean Sciences Department, University of California, Santa Cruz, CA 95064, USA.
Science. 2015 Jan 16;347(6219):255-8. doi: 10.1126/science.1258437.
El Niño-Southern Oscillation (ENSO) is a major source of global interannual variability, but its response to climate change is uncertain. Paleoclimate records from the Last Glacial Maximum (LGM) provide insight into ENSO behavior when global boundary conditions (ice sheet extent, atmospheric partial pressure of CO2) were different from those today. In this work, we reconstruct LGM temperature variability at equatorial Pacific sites using measurements of individual planktonic foraminifera shells. A deep equatorial thermocline altered the dynamics in the eastern equatorial cold tongue, resulting in reduced ENSO variability during the LGM compared to the Late Holocene. These results suggest that ENSO was not tied directly to the east-west temperature gradient, as previously suggested. Rather, the thermocline of the eastern equatorial Pacific played a decisive role in the ENSO response to LGM climate.
厄尔尼诺-南方涛动（ENSO）是全球年际变化的主要来源，但它对气候变化的响应尚不确定。末次冰盛期（LGM）的古气候记录提供了对全球边界条件（冰盖范围、大气二氧化碳部分压力）与今天不同时 ENSO 行为的深入了解。在这项工作中，我们使用单个浮游有孔虫壳的测量值来重建 LGM 时赤道太平洋地区的温度变化。深层赤道温跃层改变了东赤道冷舌的动力学，导致 LGM 期间的 ENSO 变化与全新世晚期相比减少。这些结果表明，与之前的观点不同，ENSO 与东西向温度梯度没有直接联系。相反，赤道东太平洋的温跃层在 LGM 气候对 ENSO 的响应中起决定性作用。
