Holocene El Niño–Southern Oscillation variability reflected in subtropical Australian precipitation

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. © The Author(s) 2019, corrected publication 2021
Description
Open Access: This article is licensed under a Creative Commons Attribution 4.0 International License. This article was updated by the Authors in 2021.
Keywords
Quaternary period, Southern Oscillation, Rain, Limnology, Paleoclimatology, Australia
Citation
Barr, C., Tibby, J., Leng, M. J., Tyler, J. J., Henderson, A. C. G., Overpeck, J. T., Simpson, G. L., Cole, J. E., Phipps, S. J., Marshall, J. C., McGregor, G. B., Hua, Q. & McRobie, F. H. (2019). Holocene El Niño–Southern Oscillation variability reflected in subtropical Australian precipitation. Scientific Reports, 9(1), 1-9. doi:10.1038/s41598-019-38626-3
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