PAGES Antarctica2k Temperature Reconstructions Stenni, B.; Curran, M.A.J.; Abram, N.J.; Orsi, A.J.; Goursaud, S.; Masson-Delmotte, V.; Neukom, R.; Goosse, H.; Divine, D.V.; van Ommen, T.D.; Steig, E.J.; Dixon, D.A.; Thomas, E.R.; Bertler, N.A.N.; Isaksson, E.; Ekaykin, A.A.; Werner, M.; Frezzotti, M. Stenni, B. Curran, M.A.J. Abram, N.J. Orsi, A.J. Goursaud, S. Masson-Delmotte, V. Neukom, R. Goosse, H. Divine, D.V. van Ommen, T.D. Steig, E.J. Dixon, D.A. Thomas, E.R. Bertler, N.A.N. Isaksson, E. Ekaykin, A.A. Werner, M. Frezzotti, M. Air Temperature Reconstruction earth science/paleoclimate/ice cores (ice age,null,null,year Common Era,null,ice cores,null,null,N,null) earth science/paleoclimate/ice cores (delta 18O,bulk ice,null,per mil SMOW,null,ice cores,interpolated,isotope ratio mass spectrometry,N,null) earth science/paleoclimate/climate reconstructions|ice cores (surface temperature,delta 18O,null,degree Celsius,null,climate reconstructions|ice cores,null,composite plus scale,N,"Interannual CPS reconstruction (blue line in top panel in Fig.7 for ""Whole-Antarctica"" region)") earth science/paleoclimate/climate reconstructions|ice cores (surface temperature,delta 18O,two root mean square error,degree Celsius,null,climate reconstructions|ice cores,smoothed,null,N,2RMSE error for decadal reconstruction (used for shading in second panel of Fig. 7)) earth science/paleoclimate/climate reconstructions|ice cores (age,null,null,year Common Era,null,climate reconstructions|ice cores,null,null,N,null) earth science/paleoclimate/climate reconstructions|ice cores (surface temperature,delta 18O,two root mean square error,degree Celsius,null,climate reconstructions|ice cores,null,null,N,2RMSE error for interannual reconstruction (bottom panel in Fig. 7 and used for shading in top panel of Fig. 7)) earth science/paleoclimate/climate reconstructions|ice cores (surface temperature,delta 18O,verification reduction of error,dimensionless,null,climate reconstructions|ice cores,null,null,N,Average of the two verficitation REs.) earth science/paleoclimate/climate reconstructions|ice cores (surface temperature,delta 18O,null,dimensionless,null,climate reconstructions|ice cores,null,null,N,Calibration RE of interannual reconstruction over full calibration period) earth science/paleoclimate/climate reconstructions|ice cores (surface temperature,delta 18O,verification reduction of error,dimensionless,null,climate reconstructions|ice cores,null,null,N,Verification RE of interannual reconstruction over validation window 1 (1977-1991; 3rd panel in Fig. 7).) earth science/paleoclimate/climate reconstructions|ice cores (surface temperature,delta 18O,verification reduction of error,dimensionless,null,climate reconstructions|ice cores,null,null,N,Verification RE of interannual reconstruction over validation window 2 (1961-1976; 4th panel in Fig. 7).) earth science/paleoclimate/climate reconstructions|ice cores (surface temperature,delta 18O,null,degree Celsius,null,climate reconstructions|ice cores,smoothed,null,N,Decadal CPS reconstruction (10yr running means; blue line in second panel of Fig. 7)) earth science/paleoclimate/ice cores (accumulation rate,snow,null,kilogram per square meter per year,null,ice cores,null,null,N,null) earth science/paleoclimate/reconstructions (PAGES Antarctica 2k>LATITUDE >LONGITUDE ) Climate trends in the Antarctic region remain poorly characterized, owing to the brevity and scarcity of direct climate observations and the large magnitude of interannual to decadal-scale climate variability. Here, within the framework of the PAGES Antarctica2k working group, we build an enlarged database of ice core water stable isotope records from Antarctica, consisting of 112 records. We produce both unweighted and weighted isotopic (d18O) composites and temperature reconstructions since 0 CE, binned at 5- and 10-year resolution, for seven climatically distinct regions covering the Antarctic continent. Following earlier work of the Antarctica2k working group, we also produce composites and reconstructions for the broader regions of East Antarctica, West Antarctica and the whole continent. We use three methods for our temperature reconstructions: (i) a temperature scaling based on the d18O-temperature relationship output from an ECHAM5-wiso model simulation nudged to ERA-Interim atmospheric reanalyses from 1979 to 2013, and adjusted for the West Antarctic Ice Sheet region to borehole temperature data, (ii) a temperature scaling of the isotopic normalized anomalies to the variance of the regional reanalysis temperature and (iii) a composite-plus-scaling approach used in a previous continent-scale reconstruction of Antarctic temperature since 1 CE but applied to the new Antarctic ice core database. Our new reconstructions confirm a significant cooling trend from 0 to 1900 CE across all Antarctic regions where records extend back into the 1st millennium, with the exception of the Wilkes Land coast and Weddell Sea coast regions. Within this long-term cooling trend from 0 to 1900 CE, we find that the warmest period occurs between 300 and 1000 CE, and the coldest interval occurs from 1200 to 1900 CE. Since 1900 CE, significant warming trends are identified for the West Antarctic Ice Sheet, the Dronning Maud Land coast and the Antarctic Peninsula regions, and these trends are robust across the distribution of records that contribute to the unweighted isotopic composites and also significant in the weighted temperature reconstructions. Only for the Antarctic Peninsula is this most recent century-scale trend unusual in the context of natural variability over the last 2000 years. However, projected warming of the Antarctic continent during the 21st century may soon see significant and unusual warming develop across other parts of the Antarctic continent. The extended Antarctica2k ice core isotope database developed by this working group opens up many avenues for developing a deeper understanding of the response of Antarctic climate to natural and anthropogenic climate forcings. The first long-term quantification of regional climate in Antarctica presented herein is a basis for data-model comparison and assessments of past, present and future driving factors of Antarctic climate. NCDC-Paleoclimatology https://www.ncdc.noaa.gov/data-access/paleoclimatology-data - Bauer Bruce Investigator : Stenni, B. Investigator : Curran, M.A.J. Investigator : Abram, N.J. Investigator : Orsi, A.J. Investigator : Goursaud, S. Investigator : Masson-Delmotte, V. Investigator : Neukom, R. Investigator : Goosse, H. Investigator : Divine, D.V. Investigator : van Ommen, T.D. Investigator : Steig, E.J. Investigator : Dixon, D.A. Investigator : Thomas, E.R. Investigator : Bertler, N.A.N. Investigator : Isaksson, E. Investigator : Ekaykin, A.A. Investigator : Werner, M. Investigator : Frezzotti, M. 2017-11-17 ONLINE Files online, ASCII https://www.ncdc.noaa.gov/paleo/study/22589 https://www1.ncdc.noaa.gov/pub/data/paleo/pages2k/stenni2017antarctica/ https://www1.ncdc.noaa.gov/pub/data/paleo/pages2k/stenni2017antarctica/ English https://www.ncdc.noaa.gov/paleo/study/22589 https://www1.ncdc.noaa.gov/pub/data/paleo/pages2k/stenni2017antarctica/ Barbara Stenni, Mark A. J. Curran, Nerilie J. Abram, Anais Orsi, Sentia Goursaud, Valerie Masson-Delmotte, Raphael Neukom, Hugues Goosse, Dmitry Divine, Tas van Ommen, Eric J. Steig, Daniel A. Dixon, Elizabeth R. Thomas, Nancy A. N. Bertler, Elisabeth Isaksson, Alexey Ekaykin, Martin Werner, and Massimo Frezzotti2017Antarctic climate variability on regional and continental scales over the last 2000 yearsClimate of the Past13111609-163410.5194/cp-13-1609-2017https://www.clim-past.net/13/1609/2017/ START YEAR: 0 AD * END YEAR: 2000 AD -180 -60 180 -90