noaa-recon-19767 Southern British Columbia 400 Year Summer Temperature Reconstructions Wilson, R.J.S.; Rao, R.; Rydval, M.; Wood, C.V.; Larsson, L.; Luckman, B.H. Southern British Columbia 400 Year Summer Temperature Reconstructions 2016-02-05 NCDC-Paleoclimatology ONLINE Files Pending https://www.ncdc.noaa.gov/paleo/study/19767 Investigator R.J.S. Wilson Investigator R. Rao Investigator M. Rydval Investigator C.V. Wood Investigator L. Larsson Investigator B.H. Luckman 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,95% confidence interval lower bound,degree Celsius,May-Aug,climate reconstructions|tree ring,anomalized|composited,null,N,weighted mean of five BC MJJA Tmax reconstructions earth science paleoclimate climate reconstructions|tree ring surface temperature,null,95% confidence interval upper bound,degree Celsius,May-Aug,climate reconstructions|tree ring,anomalized|composited,null,N,weighted mean of five BC MJJA Tmax reconstructions earth science paleoclimate climate reconstructions|tree ring surface temperature,null,95% confidence interval upper bound,degree Celsius,May-Aug,climate reconstructions|tree ring,anomalized|composited|smoothed,null,N,weighted mean of five BC MJJA Tmax reconstructions; smoothed 20 year spline earth science paleoclimate climate reconstructions|tree ring surface temperature,null,null,degree Celsius,May-Aug,climate reconstructions|tree ring,anomalized,null,N,Ringwidth and Blue Intensity; standard chronology earth science paleoclimate climate reconstructions|tree ring surface temperature,null,null,degree Celsius,May-Aug,climate reconstructions|tree ring,anomalized|composited,null,N,weighted mean of five BC MJJA Tmax reconstructions earth science paleoclimate climate reconstructions|tree ring surface temperature,null,null,degree Celsius,May-Aug,climate reconstructions|tree ring,anomalized|composited|smoothed,null,N,weighted mean of five BC MJJA Tmax reconstructions; smoothed 20 year spline earth science paleoclimate climate reconstructions|tree ring surface temperature,null,null,degree Celsius,May-Aug,climate reconstructions|tree ring,anomalized,null,N,IBC reconstruction; Wilson and Luckman (2003) IBC reconstruction earth science paleoclimate climate reconstructions|tree ring surface temperature,null,null,degree Celsius,May-Aug,climate reconstructions|tree ring,anomalized,null,N,ICE reconstruction; Luckman and Wilson (2005) Icefields Reconstruction earth science paleoclimate climate reconstructions|tree ring surface temperature,null,null,degree Celsius,May-Aug,climate reconstructions|tree ring,anomalized,null,N,Ringwidth and Maximum Density; standard chronology earth science paleoclimate climate reconstructions|tree ring surface temperature,null,null,degree Celsius,May-Aug,climate reconstructions|tree ring,anomalized,null,N,Ringwidth and Blue Intensity; signal free chronology earth science paleoclimate climate reconstructions|tree ring surface temperature,null,null,degree Celsius,May-Aug,climate reconstructions|tree ring,anomalized,null,N,Ringwidth and Maximum Density; signal free chronology earth science paleoclimate climate reconstructions|tree ring surface temperature,null,95% confidence interval lower bound,degree Celsius,May-Aug,climate reconstructions|tree ring,anomalized|composited|smoothed,null,N,weighted mean of five BC MJJA Tmax reconstructions; smoothed 20 year spline earth science paleoclimate reconstructions air temperature geoscientificInformation Air Temperature Reconstruction 1600 AD 1997 AD 350 cal yr BP -47 cal yr BP Complete 49 51 -122 -117 Continent North America Canada British Columbia Southern British Columbia>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

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Boulder CO 80305-3328 USA online ASCII Rob Wilson, Rohit Rao, Miloš Rydval, Cheryl Wood, Lars-Åke Larsson, and Brian H. Luckman 2014 The Holocene 24 11 1428-1438 10.1177/0959683614544051 http://hol.sagepub.com/content/24/11/1428.abstract

Maximum latewood density (MXD) is a strong proxy of summer temperatures. Despite this, there is a paucity of long MXD chronologies in the Northern Hemisphere, which limits large-scale tree-ring-based reconstructions of past temperature which are dominated by ring-width (RW) data - a weaker temperature proxy at inter-annual time-scales. This paucity likely results from the relative expense of measuring MXD and the lack of laboratories with the facilities to measure it. Herein, we test the ability of a relatively new, less expensive, tree-ring parameter, Blue Intensity (BI), to act as a surrogate parameter for MXD. BI was measured on Engelmann spruce samples from British Columbia where MXD had previously been measured to allow direct comparison between the two parameters. Signal strength analyses indicate that 8 MXD series were needed to acquire a robust mean chronology while BI needed 14. Utilising different detrending methods and parameter choices (RW + MXD vs RW + BI), a suite of reconstruction variants was developed. The explained variance from the regression modelling (1901-1995) of May-August maximum temperatures ranged from 52% to 55%. Validation tests over the earlier 1870-1900 period could not statistically distinguish between the different variants, although spectral analysis identified more lower frequency information extant in the MXD-based reconstructions - although this result was sensitive to the detrending method used. Ultimately, despite the MXD-based reconstruction explaining slightly more of the climatic variance, statistically robust reconstructions of past summer temperatures were also derived using BI. These results suggest that there is great potential in utilising BI for dendroclimatology in place of MXD data. However, more experimentation is needed to understand (1) how well BI can capture centennial and lower frequency information and (2) what biases may result from wood discolouration, either from species showing a distinct heartwood/sapwood boundary or from partly decayed sub-fossil samples. STUDY NOTES: Summer (May-June-July-August) temperature reconstructions for southern British Columbia, based on tree-ring width (RW), maximum density (MXD), and Blue Intensity (BI) measurements from 7 sites.

GET DATA https://www1.ncdc.noaa.gov/pub/data/paleo/treering/reconstructions/northamerica/canada/bc2014temp-rw-mxd-bi.txt Data File; Southern BC Summer Temperature Reconstructions - 4 Variants, RW and MXD or BI GET DATA https://www1.ncdc.noaa.gov/pub/data/paleo/treering/reconstructions/northamerica/canada/bc2014temp.txt Data File; Southern BC BC Combo Summer Temperature Reconstruction USA/NOAA DIF Version 9.8.4 2018-12-11 2018-12-11