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  • Australasian climate over the last 2,000 years: The PAGES AUS2K synthesis x
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Steven J. Phipps, Helen V. McGregor, Joëlle Gergis, Ailie J. E. Gallant, Raphael Neukom, Samantha Stevenson, Duncan Ackerley, Josephine R. Brown, Matt J. Fischer, and Tas D. van Ommen

forcings drove changes in the global climate over this period. Orbitally driven changes in insolation were small on the global scale but could be significant on the regional scale. For example, the long-term preindustrial cooling trend at high northern latitudes can be attributed to orbital forcing ( Kaufman et al. 2009 ; Esper et al. 2012 ). Changes in solar irradiance may have been globally significant, particularly the reductions in irradiance during solar grand minima ( Steinhilber et al. 2012

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Michelle Ho, Danielle C. Verdon-Kidd, Anthony S. Kiem, and Russell N. Drysdale

regions beyond the MDB where potentially useful paleoclimate rainfall records could be assembled. The purpose of the focus on rainfall, as opposed to streamflow, is that variations in streamflow are dependent on more forcing factors than rainfall such as changing environmental conditions ( Chiew et al. 1998 ; Kiem and Verdon-Kidd 2010 ; Gallant and Gergis 2011 ) and changes in flow resulting from anthropogenic regulations (e.g., extractions, diversions, retention structures, and interceptions

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Ailie J. E. Gallant, Steven J. Phipps, David J. Karoly, A. Brett Mullan, and Andrew M. Lorrey

.4 or SAM indices and the timing of nonstationarities, defined as the time when the running correlation fell outside the two-tailed 95% confidence interval. This identified how likely the nonstationarity was to be directly associated with a change in the behavior of the driving mechanism(s) compared to an injection of external noise or forcing into the system. Two statistics representing the characteristics of ENSO and the SAM were calculated: (i) the mean state, defined as the 31-yr mean value of

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B. Timbal and R. Fawcett

strengthening of the ridge (albeit not as strong as observed) only if anthropogenic external forcings are used (Timbal et al. 2010 ). In addition, Timbal et al. (2010) noted that the rainfall in SEA appears to be related to the global warming over the instrumental record, with periods of lower rainfall corresponding to periods when the global temperature of the planet was increasing, and periods with the wettest decades (e.g., 1950s and 1970s) corresponding to a period where no global warming was

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Tessa R. Vance, Tas D. van Ommen, Mark A. J. Curran, Chris T. Plummer, and Andrew D. Moy

pattern and zonal distribution of tropical Pacific SST anomalies and the behavior of the zonal wind in the South Pacific (which is affected by other climate modes, such as SAM) ( Harangozo 2004 ; Turner 2004 ; Lachlan-Cope and Connelly 2006 ). Other authors have argued that the SH response leads ENSO, since the Rossby wave pattern precedes the ENSO peak season; however, the physical processes forcing this remain unclear ( Trenberth and Shea 1987 ; Jin and Kirtman 2009 ). As noted previously, most

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Howard J. Diamond, Andrew M. Lorrey, and James A. Renwick

those based on Niño-1 or Niño-2 region SSTs. Our use of the CEI to highlight ENSO phase analogs is different from previous work in that it defines ENSO events by examining how coherent atmospheric and oceanic forcing are through an ENSO cycle. Use of this index was applied with the understanding that there are nuances for TC activity related to waxing and waning of major ENSO components and their interplay and that there are significant complexities to each event with progression through the TC

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