Eastern Canada Summer Temperature Reconstruction for the Last Millennium Gennaretti, F.; Arseneault, D.; Nicault, A.; Perreault, L.; Bégin, Y. Gennaretti, F. Arseneault, D. Nicault, A. Perreault, L. Bégin, Y. Air Temperature Reconstruction PCMA Picea mariana (Mill.) Britton, Sterns, & Poggenb. black spruce earth science/paleoclimate/climate reconstructions|tree ring (age,null,null,year Common Era,null,climate reconstructions|tree ring,null,null,N,null) earth science/paleoclimate/climate reconstructions|tree ring (surface temperature,null,null,degree Celsius,Jul-Aug,climate reconstructions|tree ring,smoothed,null,N,null) earth science/paleoclimate/climate reconstructions|tree ring (number of samples,null,null,count,null,climate reconstructions|tree ring,null,null,N,After exclusion of non-robust time intervals) earth science/paleoclimate/climate reconstructions|tree ring (number of samples,null,null,count,null,climate reconstructions|tree ring,null,null,N,After gaps were reconstructed with the analogue method) earth science/paleoclimate/climate reconstructions|tree ring (number of samples,null,null,count,null,climate reconstructions|tree ring,null,null,N,Replication within chronology L12) earth science/paleoclimate/climate reconstructions|tree ring (number of samples,null,null,count,null,climate reconstructions|tree ring,null,null,N,Replication within chronology L16) earth science/paleoclimate/climate reconstructions|tree ring (number of samples,null,null,count,null,climate reconstructions|tree ring,null,null,N,Replication within chronology L18) earth science/paleoclimate/tree ring (tree ring standardized growth index,null,expressed population signal,percent,null,tree ring,composited,null,N,On 1932 standardized tree-ring series) earth science/paleoclimate/climate reconstructions|tree ring (surface temperature,null,null,degree Celsius,Jul-Aug,climate reconstructions|tree ring,null,null,N,null) earth science/paleoclimate/climate reconstructions|tree ring (surface temperature,null,one root mean square error upper bound,degree Celsius,Jul-Aug,climate reconstructions|tree ring,null,null,N,null) earth science/paleoclimate/climate reconstructions|tree ring (surface temperature,null,one root mean square error lower bound,degree Celsius,Jul-Aug,climate reconstructions|tree ring,null,null,N,Upper 60% Confidence Range+RMSE) earth science/paleoclimate/climate reconstructions|tree ring (surface temperature,null,one root mean square error upper bound,degree Celsius,Jul-Aug,climate reconstructions|tree ring,smoothed,null,N,null) earth science/paleoclimate/climate reconstructions|tree ring (surface temperature,null,one root mean square error upper bound,degree Celsius,Jul-Aug,climate reconstructions|tree ring,smoothed,null,N,Upper 60% Confidence Range-RMSE) earth science/paleoclimate/climate reconstructions|tree ring (number of samples,null,null,count,null,climate reconstructions|tree ring,null,null,N,Replication within chronology L22) earth science/paleoclimate/tree ring (tree ring standardized growth index,null,expressed population signal,percent,null,tree ring,composited,null,N,On 6 RCS chronologies) earth science/paleoclimate/climate reconstructions|tree ring (surface temperature,null,one root mean square error upper bound,degree Celsius,Jul-Aug,climate reconstructions|tree ring,null,null,N,Upper 60% Confidence Range-RMSE) earth science/paleoclimate/climate reconstructions|tree ring (number of samples,null,null,count,null,climate reconstructions|tree ring,null,null,N,Replication within chronology L1) earth science/paleoclimate/tree ring (tree ring standardized growth index,null,average correlation coefficient,dimensionless,null,tree ring,composited,null,N,On 1932 standardized tree-ring series) earth science/paleoclimate/climate reconstructions|tree ring (surface temperature,null,one root mean square error lower bound,degree Celsius,Jul-Aug,climate reconstructions|tree ring,smoothed,null,N,null) earth science/paleoclimate/climate reconstructions|tree ring (surface temperature,null,one root mean square error lower bound,degree Celsius,Jul-Aug,climate reconstructions|tree ring,smoothed,null,N,Upper 60% Confidence Range+RMSE) earth science/paleoclimate/climate reconstructions|tree ring (surface temperature,null,one root mean square error lower bound,degree Celsius,Jul-Aug,climate reconstructions|tree ring,null,null,N,null) earth science/paleoclimate/climate reconstructions|tree ring (number of samples,null,null,count,null,climate reconstructions|tree ring,null,null,N,Replication within chronology L20) earth science/paleoclimate/tree ring (tree ring standardized growth index,null,average correlation coefficient,dimensionless,null,tree ring,composited,null,N,On 6 RCS chronologies) earth science/paleoclimate/reconstructions (Eastern Canada>LATITUDE >LONGITUDE ) Dated records of ice-cap growth from Arctic Canada recently suggested that a succession of strong volcanic eruptions forced an abrupt onset of the Little Ice Age between A.D. 1275 and 1300 [Miller GH, et al. (2012) Geophys Res Lett 39(2):L02708, 10.1029/2011GL050168]. Although this idea is supported by simulation experiments with general circulation models, additional support from field data are limited. In particular, the Northern Hemisphere network of temperature-sensitive millennial tree-ring chronologies, which principally comprises Eurasian sites, suggests that the strongest eruptions only caused cooling episodes lasting less than about 10 y. Here we present a new network of millennial tree-ring chronologies from the taiga of northeastern North America, which fills a wide gap in the network of the Northern Hemisphere's chronologies suitable for temperature reconstructions and supports the hypothesis that volcanoes triggered both the onset and the coldest episode of the Little Ice Age. Following the well-expressed Medieval Climate Anomaly (approximately A.D. 910-1257), which comprised the warmest decades of the last millennium, our tree-ring-based temperature reconstruction displays an abrupt regime shift toward lower average summer temperatures precisely coinciding with a series of 13th century eruptions centered around the 1257 Samalas event and closely preceding ice-cap expansion in Arctic Canada. Furthermore, the successive 1809 (unknown volcano) and 1815 (Tambora) eruptions triggered a subsequent shift to the coldest 40-y period of the last 1100 y. These results confirm that series of large eruptions may cause region-specific regime shifts in the climate system and that the climate of northeastern North America is especially sensitive to volcanic forcing. STUDY NOTES: Eastern Canada summer (July-August) temperature reconstruction for 910 AD - 2011 AD based on tree-ring data. Included here are the Surface Temperture reconstruction and its confidence intervals, plus EPS, Rbar, and replication of the tree-ring chronologies, as plotted in Gennaretti et al. 2014 Fig.1a-1e. The tree-ring data are included in the International Tree Ring Data Bank (ITRDB), site codes CANA458-CANA463, and also included in the Gennaretti et al. 2014 Supporting Database S1 Excel data file. NCDC-Paleoclimatology https://www.ncdc.noaa.gov/data-access/paleoclimatology-data - Bauer Bruce Investigator : Gennaretti, F. Investigator : Arseneault, D. Investigator : Nicault, A. Investigator : Perreault, L. Investigator : Bégin, Y. 2014-06-30 ONLINE Files online, ASCII https://www.ncdc.noaa.gov/paleo/study/16558 https://www1.ncdc.noaa.gov/pub/data/paleo/treering/reconstructions/northamerica/canada/east-canada2014temp.xlsx https://www1.ncdc.noaa.gov/pub/data/paleo/treering/reconstructions/northamerica/canada/east-canada2014temp.txt https://www1.ncdc.noaa.gov/pub/data/paleo/treering/reconstructions/northamerica/canada/east-canada2014temp.xlsx https://www1.ncdc.noaa.gov/pub/data/paleo/treering/reconstructions/northamerica/canada/east-canada2014temp.txt English https://www.ncdc.noaa.gov/paleo/study/16558 https://www1.ncdc.noaa.gov/pub/data/paleo/treering/reconstructions/northamerica/canada/east-canada2014temp.xlsx https://www1.ncdc.noaa.gov/pub/data/paleo/treering/reconstructions/northamerica/canada/east-canada2014temp.txt Gennaretti, F.; D. Arseneault, A. Nicault, L. Perreault, and Y. Bégin2014Volcano-induced regime shifts in millennial tree-ring chronologies from northeastern North AmericaProceedings of the National Academy of Sciences10.1073/pnas.1324220111http://www.pnas.org/content/early/2014/06/25/1324220111.abstract START YEAR: 910 AD * END YEAR: 2011 AD -90 50 -58 65