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TitleTree-ring stable isotopes for regional discharge reconstruction in eastern Labrador and teleconnection with the Arctic Oscillation
AuthorDinis, L; Bégin, C; Savard, M M; Marion, J; Brigode, P; Alvarez, C
SourceClimate Dynamics vol. 53, issue 5-6, 2019 p. 3625-3640, (Open Access)
Alt SeriesNatural Resources Canada, Contribution Series 20180208
PublisherSpringer Science and Business Media LLC
Mediapaper; on-line; digital
File formatpdf (Adobe® Reader®); html
ProvinceNewfoundland and Labrador
AreaLabrador; Churchill River; Happy Valley-Goose Bay; Cartwright
Lat/Long WENS -64.0000 -56.0000 56.0000 52.0000
SubjectsEconomics and Industry; Nature and Environment; environmental geology; hydrogeology; climatology; stable isotope studies; carbon isotopes; oxygen isotopes; dendrochronology; surface waters; rivers; discharge rates; climate effects; hydrologic environment; hydrologic budget; drainage systems; energy; hydroelectric power; statistical analyses; High Boreal Forest Ecoregion; Arctic Oscillation; methodology; tree rings; climate change; reconstructions; ANATEM method
Illustrationslocation maps; time series; tables; plots
ProgramClimate Change Geoscience, Essential Climate Variable Monitoring
Released2019 04 26
AbstractIn northeastern Canada (Labrador), instrumental climatic data cover less than 70 years and long reconstructions from natural archives are non-existent. This study specifically aims at helping filling this gap of knowledge by testing the possibility of reconstructing the regional 1800-2009 discharge of the lower Churchill River from black spruce tree-ring delta-13C and delta-18O series. The results illustrate direct relationships of summer climatic variables/derived parameter (maximum temperature, total precipitation and vapor pressure deficit) with tree-ring isotope values. Importantly, they show an inverse correlation between combined tree-ring isotope series and regional river discharge due to common climate forcing. To a lesser extent, transpiration also affects the river discharge and tree-ring isotopic compositions. The reconstructed river discharge series agrees with an independent reconstruction based on the ANATEM method (1880-2009 period). The agreement between the two reconstructions validates the two approaches for reconstructing regional hydroclimatic conditions at high latitudes. Moreover, the reconstructions suggest that summer discharge has decreased over the past 200 years in eastern Labrador and more broadly at the Québec-Labrador peninsula scale. This trend correlates with the long-term summer Arctic Oscillation (AO) that influences summer regional climatic conditions. This research contributes with other studies to build up observations linking summer AO and eastern Canada climatic conditions, and calls for research on mechanisms explaining these relationships during summer.
Summary(Plain Language Summary, not published)
In Labrador, hydroclimatic series used for simulating water regime variability cover less than seventy years. Model calibration period is thus too short to represent natural variability of water regime and drought episode recurrence, which is problematic for estimating real risks associated to low level. This study shows that combining tree-ring carbon and oxygen isotope series can be used to reconstruct regional discharge and that summer discharge shows an overall decrease over the past 200 years. Moreover, results show significant relationship between reconstructed discharge and Arctic Oscillation (AO) in summer, whereas the AO index is generally recognized to influence winter conditions in this region. For this reason, we suggest that new researches are needed to understand mechanisms explaining this relationship during summer.