noaa-recon-16463 Northwestern Canada 350 Year Summer Temperature Reconstructions Szeicz, J.M.; MacDonald, G.M. Northwestern Canada 350 Year Summer Temperature Reconstructions 1995-11-01 NCDC-Paleoclimatology ONLINE Files Pending https://www.ncdc.noaa.gov/paleo/study/16463 Investigator J.M. Szeicz Investigator G.M. MacDonald 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 temperature,null,null,degree Celsius,Jun-Jul,climate reconstructions|tree ring,null,null,N,null earth science paleoclimate reconstructions air temperature geoscientificInformation Air Temperature Reconstruction temperature 1638 AD 1988 AD 312 cal yr BP -38 cal yr BP Complete 64 65.3 -139.5 -127 Continent North America Canada Northwestern Canada>LATITUDE >LONGITUDE None Please cite original publication, online resource, dataset and publication DOIs (where available), and date accessed when using downloaded data. If there is no publication information, please cite investigator, title, online resource, and date accessed. The appearance of external links associated with a dataset does not constitute endorsement by the Department of Commerce/National Oceanic and Atmospheric Administration of external Web sites or the information, products or services contained therein. For other than authorized activities, the Department of Commerce/NOAA does not exercise any editorial control over the information you may find at these locations. These links are provided consistent with the stated purpose of this Department of Commerce/NOAA Web site. English DOC/NOAA/NESDIS/NCEI National Centers for Environmental Information, NESDIS, NOAA, U.S. Department of Commerce https://www.ncdc.noaa.gov/data-access/paleoclimatology-data DATA Center Contact Bruce Bauer bruce.a.bauer@noaa.gov paleo@noaa.gov 303-497-6280 303-497-6513

325 Broadway, E/NE31

Boulder CO 80305-3328 USA online ASCII Julian M. Szeicz and Glen M. MacDonald 1995 Quaternary Research 44 2 257-266 http://www.sciencedirect.com/science/article/pii/S0033589485710708

Ring widths from five Picea glauca stands at the alpine treeline in northwestern Canada are used to investigate climate-growth responses and to develop a long reconstruction of summer temperatures. Response function and linear regression analyses indicate that the radial growth response of these trees to climate varies with age and site. At most sites, the period of significant positive response to growing season temperatures declines with tree age. Age-dependent and standard (age independent) models are then used to develop two reconstructions of June-July temperatures for northwestern Canada extending back to A.D. 1638. Calibration statistics were similar for both models, but the standard model performed poorly during verification. The reconstruction produced using age-dependent modeling suggests June-July temperatures were cooler than present throughout most of the past 350 years, with the exception of the late 18th century. Particularly cool periods occurred at ~1700 and in the mid-19th century. In constast, the standard model suggests that temperatures were similar to or warmer than present during the last 350 years. The age-dependent reconstruction compares favorably with other proxy climate records from northern North America. Age-dependent dendroclimatic modeling can provide a sensitive record of recent climatic change that allows the inclusion of previously rejected sites into dendroclimatic analyses. STUDY NOTES: Reconstructed June-July temperatures in northwestern Canada derived from tree-ring data. (calibrated with Dawson/Norman Wells average, 1909-1989), produced using age-dependent modelling.

GET DATA https://www1.ncdc.noaa.gov/pub/data/paleo/treering/reconstructions/nwcanada/nwcan-recon.txt Data File; Northwestern Canada June-July Temperature Reconstruction USA/NOAA DIF Version 9.8.4 2018-12-11 2018-12-11