Firth River Alaska 930 Year Maximum Latewood Density Temperature Reconstruction Anchukaitis, K.J.; D'Arrigo, R.D.; Andreu-Hayles, L.; Frank, D.C.; Verstege, A.; Curtis, A.E.; Buckley, B.M.; Jacoby, G.C.; Cook, E.R. Anchukaitis, K.J. D'Arrigo, R.D. Andreu-Hayles, L. Frank, D.C. Verstege, A. Curtis, A.E. Buckley, B.M. Jacoby, G.C. Cook, E.R. Air Temperature Reconstruction temperature 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,ring density,null,degree Celsius,Jul-Aug,climate reconstructions|tree ring,anomalized,null,N,based on latewood density; 1951–1980 reference period) earth science/paleoclimate/tree ring (tree ring standardized growth index,null,null,null,null,tree ring,composited,standard,N,Thelon MXD) earth science/paleoclimate/tree ring (tree ring standardized growth index,null,null,null,null,tree ring,composited,null,N,Firth River 1236 MXD) earth science/paleoclimate/tree ring (tree ring standardized growth index,null,null,null,null,tree ring,composited,standard,N,Coppermine MXD) earth science/paleoclimate/climate reconstructions|tree ring (surface temperature,ring density,two standard deviations lower bound,degree Celsius,Jul-Aug,climate reconstructions|tree ring,anomalized,null,N,based on latewood density; 1951–1980 reference period; +/-2sigma uncertainties estimated as the smoothed ensemble standard error of prediction) earth science/paleoclimate/climate reconstructions|tree ring (surface temperature,ring density,two standard deviations upper bound,degree Celsius,Jul-Aug,climate reconstructions|tree ring,anomalized,null,N,based on latewood density; 1951–1980 reference period; +/-2sigma uncertainties estimated as the smoothed ensemble standard error of prediction) earth science/paleoclimate/reconstructions (Firth River 1236>LATITUDE 68.65>LONGITUDE -141.63) Northwestern North America has one of the highest rates of recent temperature increase in the world, but the putative "divergence problem" in dendroclimatology potentially limits the ability of tree-ring proxy data at high latitudes to provide long-term context for current anthropogenic change. Here, summer temperatures are reconstructed from a Picea glauca maximum latewood density (MXD) chronology that shows a stable relationship to regional temperatures and spans most of the last millennium at the Firth River in northeastern Alaska. The warmest epoch in the last nine centuries is estimated to have occurred during the late twentieth century, with average temperatures over the last 30 yr of the reconstruction developed for this study [1973-2002 in the Common Era (CE)] approximately 1.3° ± 0.4°C warmer than the long-term preindustrial mean (1100-1850 CE), a change associated with rapid increases in greenhouse gases. Prior to the late twentieth century, multidecadal temperature fluctuations covary broadly with changes in natural radiative forcing. The findings presented here emphasize that tree-ring proxies can provide reliable indicators of temperature variability even in a rapidly warming climate. STUDY NOTES: Tree-ring maximum latewood density (MXD) based reconstruction of July-August temperature from northeastern Alaska from trees samples in the Firth River valley. This series is based on Signal-Free (SF) standardization of a maximum latewood density data collection of living and subfossil samples. Data are from Figure 7 and 9, Anchukaitis et al. 2013. Summer (July and August) weighted mean ensemble Firth River temperature reconstruction smoothed with a 30-year Gaussian filter and including +/-2sigma uncertainties estimated as the smoothed ensemble Standard Error of Prediction. Reconstructed values are anomalies from the 1951–1980 mean July-August GISTEMP for the Firth River the ensemble methods by their validation period bias such that more skillful reconstructions receive a larger weight for the ensemble mean. The raw data are archived in the ITRDB as ak132x: ftp://ftp.ncdc.noaa.gov/pub/data/paleo/treering/measurements/northamerica/usa/ak132x.rwl NCDC-Paleoclimatology https://www.ncdc.noaa.gov/data-access/paleoclimatology-data - Bauer Bruce Investigator : Anchukaitis, K.J. Investigator : D'Arrigo, R.D. Investigator : Andreu-Hayles, L. Investigator : Frank, D.C. Investigator : Verstege, A. Investigator : Curtis, A.E. Investigator : Buckley, B.M. Investigator : Jacoby, G.C. Investigator : Cook, E.R. 2013-08-19 ONLINE Files online, ASCII https://www.ncdc.noaa.gov/paleo/study/14789 https://www1.ncdc.noaa.gov/pub/data/paleo/treering/reconstructions/northamerica/usa/alaska/firth2013temperature.txt https://www1.ncdc.noaa.gov/pub/data/paleo/treering/reconstructions/northamerica/usa/alaska/firth2013temperature.txt English https://www.ncdc.noaa.gov/paleo/study/14789 https://www1.ncdc.noaa.gov/pub/data/paleo/treering/reconstructions/northamerica/usa/alaska/firth2013temperature.txt Kevin J. Anchukaitis, Rosanne D. D'Arrigo, Laia Andreu-Hayles, David Frank, Anne Verstege, Ashley Curtis, Brendan M. Buckley, Gordon C. Jacoby, Edward R. Cook. 2013. Tree-Ring-Reconstructed Summer Temperatures from Northwestern North America during the Last Nine Centuries. Journal of Climate, Vol. 26, Issue 10, pp. 3001-3012. DOI: 10.1175/JCLI-D-11-00139.1 START YEAR: 1073 AD * END YEAR: 2002 AD -141.63 68.65 -141.63 68.65