TY - JOUR
T1 - Reconstruction of Ob River, Russia, discharge from ring widths of floodplain trees
AU - Agafonov, Leonid I.
AU - Meko, David M.
AU - Panyushkina, Irina P.
N1 - Funding Information:
This work was supported by grants from the CRDF Global Research Partnerships program (# RUC1-7075-EK-12 and # FSCX-15-61824-0 ), and Russian Foundation for Basic Research (# 13-04-01964 , # 05-04-48298 , # 00-05-65041 ). We acknowledge also the generous assistance in provision of a research vessel and land facilities by the Institute of Plant and Animal Ecology, Ural Branch of Russian Academy of Sciences, in Yekaterinburg and Labytnangi.
Publisher Copyright:
© 2016 Elsevier B.V.
PY - 2016/12/1
Y1 - 2016/12/1
N2 - The 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 (R2 = 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.
AB - The 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 (R2 = 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.
KW - Arctic Ocean warming
KW - Dendrohydrology
KW - Northern Eurasia river discharge variability
KW - Ob River
KW - Streamflow reconstruction
KW - Tree rings
UR - http://www.scopus.com/inward/record.url?scp=85003881548&partnerID=8YFLogxK
UR - http://www.scopus.com/inward/citedby.url?scp=85003881548&partnerID=8YFLogxK
U2 - 10.1016/j.jhydrol.2016.09.031
DO - 10.1016/j.jhydrol.2016.09.031
M3 - Article
AN - SCOPUS:85003881548
VL - 543
SP - 198
EP - 207
JO - Journal of Hydrology
JF - Journal of Hydrology
SN - 0022-1694
ER -