Drought variability in the eastern Australia and New Zealand summer drought atlas (ANZDA, CE 1500–2012) modulated by the Interdecadal Pacific Oscillation
Agricultural production across eastern Australia and New Zealand is highly vulnerable to drought, but there is a dearth of observational drought information prior to CE 1850. Using a comprehensive network of 176 drought-sensitive tree-ring chronologies and one coral series, we report the first Southern Hemisphere gridded drought atlas extending back to CE 1500. The austral summer (December–February) Palmer drought sensitivity index reconstruction accurately reproduces historically documented drought events associated with the first European settlement of Australia in CE 1788, and the leading principal component explains over 50% of the underlying variance. This leading mode of variability is strongly related to the Interdecadal Pacific Oscillation tripole index (IPO), with a strong and robust antiphase correlation between (1) eastern Australia and the New Zealand North Island and (2) the South Island. Reported positive, negative, and neutral phases of the IPO are consistently reconstructed by the drought atlas although the relationship since CE 1976 appears to have weakened.
Climate Change Research Centre, School of Biological, Earth and Environmental Sciences, University of New South Wales, Sydney, NSW 2015, Australia;Lamont-Doherty Earth Observatory of Columbia University, Palisades, NY 10964, USA;Climate Change Research Centre, School of Biological, Earth and Environmental Sciences, University of New South Wales, Sydney, NSW 2015, Australia;School of Ecosystem and Forest Sciences, University of Melbourne, Richmond, Victoria, 3121, Australia;Gondwana Tree-ring Laboratory, P O Box 14, Little River, Canterbury, 7546, New Zealand;Lamont-Doherty Earth Observatory of Columbia University, Palisades, NY 10964, USA;NASA Goddard Institute for Space Studies, 2880 Broadway, New York, NY 10025, USA;Ecosystems Research Group, School of Plant Biology, The University of Western Australia, Crawley, WA 2016, Australia;Australian Institute of Marine Science, PMB 3, Townsville MC, Townsville, QLD 4810, Australia;Ecosystems Research Group, School of Plant Biology, The University of Western Australia, Crawley, WA 2016, Australia;School of Ecosystem and Forest Sciences, University of Melbourne, Richmond, Victoria, 3121, Australia
Recommended Citation:
Jonathan G Palmer,Edward R Cook,Chris S M Turney,et al. Drought variability in the eastern Australia and New Zealand summer drought atlas (ANZDA, CE 1500–2012) modulated by the Interdecadal Pacific Oscillation[J]. Environmental Research Letters,2015-01-01,10(12)