Browsing by Author "Reimer, RW"

Now showing 1 - 2 of 2
  • No Thumbnail Available
    Item
    Compatibility of atmospheric 14CO2 measurements: comparing the heidelberg low-level counting facility to international accelerator mass spectrometry (AMS) laboratories
    (Cambridge University Press, 2016-09-19) Hammer, S; Friedrich, R; Kromer, B; Cherkinsky, A; Lehman, SJ; Meijer, HAJ; Nakamura, T; Palonen, V; Reimer, RW; Smith, AM; Southen, JR; Szidat, S; Turnbull, J; Uchida, M
    Combining atmospheric Δ14CO2 data sets from different networks or laboratories requires secure knowledge on their compatibility. In the present study, we compare Δ14CO2 results from the Heidelberg low-level counting (LLC) laboratory to 12 international accelerator mass spectrometry (AMS) laboratories using distributed aliquots of five pure CO2 samples. The averaged result of the LLC laboratory has a measurement bias of –0.3±0.5‰ with respect to the consensus value of the AMS laboratories for the investigated atmospheric Δ14C range of 9.6 to 40.4‰. Thus, the LLC measurements on average are not significantly different from the AMS laboratories, and the most likely measurement bias is smaller than the World Meteorological Organization (WMO) interlaboratory compatibility goal for Δ14CO2 of 0.5‰. The number of intercomparison samples was, however, too small to determine whether the measurement biases of the individual AMS laboratories fulfilled the WMO goal. © 2016 by the Arizona Board of Regents on behalf of the University of Arizona
  • No Thumbnail Available
    Item
    SHCal13 Southern Hemisphere calibration, 0–50,000 years cal BP
    (University Arizona Department Geosciences, 2016-02-09) Hogg, AG; Hua, Q; Blackwell, PG; Niu, M; Buck, CE; Guilderson, TP; Heaton, TJ; Palmer, JG; Reimer, PJ; Reimer, RW; Turney, CSM; Zimmerman, SRH
    The Southern Hemisphere SHCal04 radiocarbon calibration curve has been updated with the addition of new data sets extending measurements to 2145 cal BP and including the ANSTO Younger Dryas Huon pine data set. Outside the range of measured data, the curve is based upon the ern Hemisphere data sets as presented in IntCal13, with an interhemispheric offset averaging 43 ± 23 yr modeled by an autoregressive process to represent the short-term correlations in the offset. © 2013, by the Arizona Board of Regents on behalf of the University of Arizona.