Columbia Icefield 1,000 Year Decadal Tree-Ring Isotope, RH, and Temperature Edwards, T.W.D.; Birks, S.J.; Luckman, B.H.; MacDonald, G.M. Edwards, T.W.D. Birks, S.J. Luckman, B.H. MacDonald, G.M. Air Temperature Reconstruction Other Hydroclimate Reconstruction PCEN Picea engelmannii Parry ex Engelm. Engelmann spruce PIAL Pinus albicaulis Engelm. whitebark pine earth science/paleoclimate/tree ring (age at sample end,null,null,year Common Era,null,tree ring,null,null,N,null) earth science/paleoclimate/climate reconstructions|tree ring (surface temperature,null,null,standard deviation unit,winter,climate reconstructions|tree ring,anomalized,null,N,anomalized from 1941-1990 reference period) earth science/paleoclimate/tree ring (delta 13C,cellulose,null,per mil VPDB,null,tree ring,averaged|corrected,isotope ratio mass spectrometry,N,"average of 16 trees, 2-5 radii each; corrected for the decrease in atmospheric δ13C values due to the rise in CO2 caused by fossil fuel combustion since the beginning of the industrialization") earth science/paleoclimate/tree ring (delta 18O,cellulose,null,per mil VSMOW,null,tree ring,averaged,null,N,"average of 12 trees, 2-4 radii each") earth science/paleoclimate/climate reconstructions|tree ring (relative humidity,null,null,standard deviation unit,growing season,climate reconstructions|tree ring,anomalized,null,N,anomalized from 1941-1990 reference period) earth science/paleoclimate/tree ring (delta 18O,cellulose,one standard deviation,per mil VSMOW,null,tree ring,averaged,null,N,"average of 12 trees, 2-4 radii each") earth science/paleoclimate/tree ring (age at sample start,null,null,year Common Era,null,tree ring,null,null,N,null) earth science/paleoclimate/tree ring (delta 13C,cellulose,one standard deviation,per mil VPDB,null,tree ring,averaged|corrected,isotope ratio mass spectrometry,N,"average of 16 trees, 2-5 radii each; corrected for the decrease in atmospheric δ13C values due to the rise in CO2 caused by fossil fuel combustion since the beginning of the industrialization") earth science/paleoclimate/tree-ring earth science/paleoclimate/tree-ring (Columbia Icefield>LATITUDE >LONGITUDE ) Modelling of tree-ring d13C and d18O data from the Columbia Icefield area in the eastern Rocky Mountains of western Canada provides fuller understanding of climatic and hydrologic variability over the past 1000 yr in this region, based on reconstruction of changes in growth season atmospheric relative humidity (RHgrs), winter temperature (Twin) and the precipitation d18O-Twin relation. The Little Ice Age (~AD 1530s-1890s) is marked by low RHgrs and Twin and a d18O-Twin relation offset from that of the present, reflecting enhanced meridional circulation and persistent influence of Arctic air masses. Independent proxy hydrologic evidence suggests that snowmelt sustained relatively abundant streamflow at this time in rivers draining the eastern Rockies. In contrast, the early millennium was marked by higher RHgrs and Twin and a d18O-Twin relation like that of the 20th century, consistent with pervasive influence of Pacific air masses because of strong zonal circulation. Especially mild conditions prevailed during the "Medieval Climate Anomaly" ~AD 1100-1250, corresponding with evidence for reduced discharge in rivers draining the eastern Rockies and extensive hydrological drought in neighbouring western USA. STUDY NOTES: Tree-ring isotopic data (d18O and d13C) from the Columbia Icefield area of the Canadian Rockies at decadal resolution, plus reconstructed winter temperature (Twin) and growth season atmospheric relative humidity (RHgrs) over the past 1000 years. Composite d13C and d18O chronologies spanning AD 951-1990 were developed from cross-dated 10-yr increments of Picea engelmannii (Engelmann spruce) and Pinus albicaulis (whitebark pine) collected from 16 subfossil snags and living-tree sequences at three sites near the Athabasca, Robson, and Bennington glaciers. Carbon-isotope analyses were performed on cellulose by closed-tube combustion followed by dual-inlet mass spectrometry. The d13C data were corrected for changing d13C of atmospheric CO2 post-1850. Cellulose oxygen-isotope data were obtained by high-temperature pyrolysis followed by CF-IRMS. Growth season RH and winter T were reconstructed using a coupled isotope response-surface approach. See Edwards et al. (2008) for full details. IITRDB12 NCDC-Paleoclimatology https://www.ncdc.noaa.gov/data-access/paleoclimatology-data - Bauer Bruce Investigator : Edwards, T.W.D. Investigator : Birks, S.J. Investigator : Luckman, B.H. Investigator : MacDonald, G.M. 2014-12-10 ONLINE Files online, ASCII https://www.ncdc.noaa.gov/paleo/study/17576 https://www1.ncdc.noaa.gov/pub/data/paleo/treering/isotope/northamerica/canada/columbia2008iso.txt https://www1.ncdc.noaa.gov/pub/data/paleo/treering/isotope/northamerica/canada/columbia2008iso.txt English https://www.ncdc.noaa.gov/paleo/study/17576 https://www1.ncdc.noaa.gov/pub/data/paleo/treering/isotope/northamerica/canada/columbia2008iso.txt Thomas W.D. Edwards, S. Jean Birks, Brian H. Luckman, Glen M. MacDonald2008Climatic and hydrologic variability during the past millennium in the eastern Rocky Mountains and northern Great Plains of western CanadaQuaternary Research702188-19710.1016/j.yqres.2008.04.013http://www.sciencedirect.com/science/article/pii/S0033589408000604 START YEAR: 951 AD * END YEAR: 1990 AD -119 52 -117 53