Australasian Temperature Reconstructions Spanning the Last Millennium Gergis, J.; Neukom, R.; Gallant, A.J.E.; Karoly, D.J. Gergis, J. Neukom, R. Gallant, A.J.E. Karoly, D.J. Air Temperature Reconstruction earth science/paleoclimate/reconstructions earth science/paleoclimate/reconstructions (Australasia>LATITUDE >LONGITUDE ) Multiproxy warm season (September-February) temperature reconstructions are presented for the combined land-ocean region of Australasia (0-50S, 110E-180E) covering 1000-2001. Using between 2 (R2) and 28 (R28) paleoclimate records, four 1000-member ensemble reconstructions of regional temperature are developed using four statistical methods: principal component regression (PCR), composite plus scale (CPS), Bayesian hierarchical models (LNA), and pairwise comparison (PaiCo). The reconstructions are then compared with a three-member ensemble of GISS-E2-R climate model simulations and independent paleoclimate records. Decadal fluctuations in Australasian temperatures are remarkably similar between the four reconstruction methods. There are, however, differences in the amplitude of temperature variations between the different statistical methods and proxy networks. When the R28 network is used, the warmest 30-yr periods occur after 1950 in 77% of ensemble members over all methods. However, reconstructions based on only the longest records (R2 and R3 networks) indicate that single 30- and 10-yr periods of similar or slightly higher temperatures than in the late twentieth century may have occurred during the first half of the millennium. Regardless, the most recent instrumental temperatures (1985-2014) are above the 90th percentile of all 12 reconstruction ensembles (four reconstruction methods based on three proxy networks-R28, R3, and R2). The reconstructed twentieth-century warming cannot be explained by natural variability alone using GISS-E2-R. In this climate model, anthropogenic forcing is required to produce the rate and magnitude of post-1950 warming observed in the Australasian region. These paleoclimate results are consistent with other studies that attribute the post-1950 warming in Australian temperature records to increases in atmospheric greenhouse gas concentrations. STUDY NOTES: Warm season (September-February) temperature reconstruction ensembles for the combined HadCRUT3v land and ocean region of Australasia (0S-50S, 110E-180E) covering A.D. 1000-2001. NCDC-Paleoclimatology https://www.ncdc.noaa.gov/data-access/paleoclimatology-data - Bauer Bruce Investigator : Gergis, J. Investigator : Neukom, R. Investigator : Gallant, A.J.E. Investigator : Karoly, D.J. 2016-07-10 ONLINE Files online, ASCII https://www.ncdc.noaa.gov/paleo/study/12915 https://www1.ncdc.noaa.gov/pub/data/paleo/reconstructions/gergis2016/ https://www1.ncdc.noaa.gov/pub/data/paleo/reconstructions/gergis2016/readme-gergis2016.txt https://www1.ncdc.noaa.gov/pub/data/paleo/reconstructions/gergis2016/ https://www1.ncdc.noaa.gov/pub/data/paleo/reconstructions/gergis2016/readme-gergis2016.txt English https://www.ncdc.noaa.gov/paleo/study/12915 https://www1.ncdc.noaa.gov/pub/data/paleo/reconstructions/gergis2016/ https://www1.ncdc.noaa.gov/pub/data/paleo/reconstructions/gergis2016/readme-gergis2016.txt Joelle Gergis, Raphael Neukom, Ailie J.E. Gallant, and David J. Karoly2016Australasian temperature reconstructions spanning the last millenniumJournal of Climate29155365-539210.1175/JCLI-D-13-00781.1http://journals.ametsoc.org/doi/abs/10.1175/JCLI-D-13-00781.1 START YEAR: 1000 AD * END YEAR: 2001 AD 110 -50 180 0