Bayesian multiproxy temperature reconstruction with black spruce ring widths and stable isotopes from the northern Quebec taiga

• Published in: Climate dynamics 2017-12, Vol.49 (11-12), p.4107-4119
• Main Authors: Gennaretti, Fabio, Huard, David, Naulier, Maud, Savard, Martine, Bégin, Christian, Arseneault, Dominique, Guiot, Joel
• Format: Article
• Language: English
• Subjects: Analysis; Bayesian analysis; Chronology; Climate models; Climatology; Continental interfaces, environment; Datasets; Earth and Environmental Science; Earth Sciences; Environmental aspects; Geophysics/Geodesy; Isotopes; Oceanography; Probability theory; Sciences of the Universe; Sensitivity analysis; Stable isotopes; Taiga; Temperature; Temperature effects; Volcanic activity; Volcanic eruption effects; Volcanic eruptions; Width
• ISSN: 0930-7575; 1432-0894
• DOI: 10.1007/s00382-017-3565-5

Northeastern North America has very few millennium-long, high-resolution climate proxy records. However, very recently, a new tree-ring dataset suitable for temperature reconstructions over the last millennium was developed in the northern Quebec taiga. This dataset is composed of one δ 18 O and six ring width chronologies. Until now, these chronologies have only been used in independent temperature reconstructions (from δ 18 O or ring width) showing some differences. Here, we added to the dataset a δ 13 C chronology and developed a significantly improved millennium-long multiproxy reconstruction (997–2006 CE) accounting for uncertainties with a Bayesian approach that evaluates the likelihood of each proxy model. We also undertook a methodological sensitivity analysis to assess the different responses of each proxy to abrupt forcings such as strong volcanic eruptions. Ring width showed a larger response to single eruptions and a larger cumulative impact of multiple eruptions during active volcanic periods, δ 18 O showed intermediate responses, and δ 13 C was mostly insensitive to volcanic eruptions. We conclude that all reconstructions based on a single proxy can be misleading because of the possible reduced or amplified responses to specific forcing agents.