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Abstract

The La Niña and El Niño phases of the El Niño-Southern Oscillation (ENSO) have major impacts on regional rainfall patterns around the globe, with substantial environmental, societal and economic implications. Long-term perspectives on ENSO behaviour, under changing background conditions, are essential to anticipating how ENSO phases may respond under future climate scenarios. Here, we derive a 7700-year, quantitative precipitation record using carbon isotope ratios from a single species of leaf preserved in lake sediments from subtropical eastern Australia. We find a generally wet (more La Niña-like) mid-Holocene that shifted towards drier and more variable climates after 3200 cal. yr BP, primarily driven by increasing frequency and strength of the El Niño phase. Climate model simulations implicate a progressive orbitally-driven weakening of the Pacific Walker Circulation as contributing to this change. At centennial scales, high rainfall characterised the Little Ice Age (~1450–1850 CE) in subtropical eastern Australia, contrasting with oceanic proxies that suggest El Niño-like conditions prevail during this period. Our data provide a new western Pacific perspective on Holocene ENSO variability and highlight the need to address ENSO reconstruction with a geographically diverse network of sites to characterise how both ENSO, and its impacts, vary in a changing climate.

Item Type:	Article
Authors/Creators:	Barr, C and Tibby, J and Leng, MJ and Tyler, JJ and Henderson, ACG and Overpeck, JT and Simpson, GL and Cole, JE and Phipps, SJ and Marshall, JC and McGregor, GB and Hua, Q and McRobie, FH
Keywords:	ENSO, El Nino-Southern Oscillation, Holocene, climate variability, subtropics, Australia, precipitation
Journal or Publication Title:	Scientific Reports
Publisher:	Nature Publishing Group
ISSN:	2045-2322
DOI / ID Number:	https://doi.org/10.1038/s41598-019-38626-3
Copyright Information:	Copyright 2019 The Authors. Licensed under Creative Commons Attribution 4.0 International (CC BY 4.0) https://creativecommons.org/licenses/by/4.0/
Related URLs:	Google Scholar: Phipps, SJ
Item Statistics:	View statistics for this item

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