Reconstruction of Ob River, Russia, discharge from ring widths of floodplain trees
AffiliationLaboratory of Tree-Ring Research, University of Arizona
Arctic Ocean warming
Northern Eurasia river discharge variability
MetadataShow full item record
PublisherELSEVIER SCIENCE BV
CitationReconstruction of Ob River, Russia, discharge from ring widths of floodplain trees 2016, 543:198 Journal of Hydrology
JournalJournal of Hydrology
Rights© 2016 Elsevier B.V. All rights reserved.
Collection InformationThis item from the UA Faculty Publications collection is made available by the University of Arizona with support from the University of Arizona Libraries. If you have questions, please contact us at firstname.lastname@example.org.
AbstractThe Ob is the third largest Eurasian river supplying heat and freshwater to the Arctic Ocean. These inputs influence water salinity, ice coverage, ocean temperatures and ocean circulation, and ultimately the global climate system. Variability of Ob River flow on long time scales is poorly understood, however, because gaged flow records are short. Eleven tree-ring width chronologies of Pinus sibirica and Larix sibirica are developed from the floodplain of the Lower Ob River, analyzed for hydroclimatic signal and applied as predictors in a regression model to reconstruct 8-month average (December-July) discharge of the Ob River at Salekhard over the interval 1705-2012 (308 yrs). Correlation analysis suggests the signal for discharge comes through air temperature: high discharge and floodplain water levels favor cool growing-season air temperature, which limits tree growth for the sampled species at these high latitudes. The reconstruction model (R-2 = 0.31, 1937-2009 calibration period) is strongly supported by cross validation and analysis of residuals. Correlation of observed with reconstructed discharge improves with smoothing. The long-term reconstruction correlates significantly with a previous Ob River reconstruction from ring widths of trees outside the Ob River floodplain and extends that record by another century. Results suggest that large multi-decadal swings in discharge have occurred at irregular intervals, that variations in the 20th and 21st centuries have been within the envelope of natural variability of the past 3 centuries, and that discharge data for 1937-2009 underestimate both the variability and persistence of discharge in the last 3 centuries. The reconstruction gives ecologists, climatologists and water resource planners a long-term context for assessment of climate change impacts.
Note24 month embargo; Available online 13 September 2016
VersionFinal accepted manuscript
SponsorsCRDF Global Research Partnerships program [RUC1-7075-EK-12, FSCX-15-61824-0]; Russian Foundation for Basic Research [13-04-01964, 05-04-48298, 00-05-65041]