HR: 0800h
AN: PP41A-0179 [Abstracts]
TI: Deterministic hydrological model to reconstruct the last 400 years of runoff and climate variations using the properties of the varved lake sediments in the Canadian Arctic
AU: * Ciobanas, N
EM: nicoleta.ciobanas@ete.inrs.ca
AF: Institut national de la recherche scientifique, Eau, Terre et Environnement, 490, rue de la
couronne, Québec, Qc G1K 9A9, Canada
AU: * Ciobanas, N
EM: nicoleta.ciobanas@ete.inrs.ca
AF: GEOTOP-UQAM-McGill, C.P. 8888, Succ. Centre-Ville, Montreal, QC H3C 3P8, Canada
AU: Francus, P
EM: pfrancus@ete.inrs.ca
AF: Institut national de la recherche scientifique, Eau, Terre et Environnement, 490, rue de la
couronne, Québec, Qc G1K 9A9, Canada
AU: Francus, P
EM: pfrancus@ete.inrs.ca
AF: GEOTOP-UQAM-McGill, C.P. 8888, Succ. Centre-Ville, Montreal, QC H3C 3P8, Canada
AB:
The aim of this study is to develop a deterministic hydrological model in order to reconstruct the last 400 years of
runoff using the properties of varved sediments from Sawtooth Lake-Ellesmere Island. Varved sediments can
provide well-constrained records of interannual-to centennial-scale variation of climatic and hydrologic cycles,
such as the North Atlantic Oscillation and Arctic Oscillation. Using image analysis technique of microscopic
views, we can determine some properties of varved sediments, including the grain size of each year of
sedimentation. Grain size and sediment input are mainly controlled by complex hydroclimatic processes within
the watershed and such a direct correlation is not obvious. In order to better understand the relation between
meteorological data and the waterflow to the lake, we developed a hydrological model. This deterministic model
is based on a simple water balance equation at the scale of the watershed and uses the following parameters:
the runoff, the evapotranspiration, the snowmelting and the soil's humidity storage. To estimate the
evapotranspiration, Penman-Monteith's model was used. The snow melting was determined using the concept of
"degree day". The model forced by climatic data successfully reproduced the flow measurements obtained
during 1998. Moreover, the predicted runoff correlates well with the varves properties for the last 50 years. Hence,
we used our model to reconstruct the climate of the last 400 years using the varved sediment. Our reconstruction
compares well with the decadal and multi-decadal variations of the North Atlantic Oscillation and Arctic Oscillation.
DE: 9315 Arctic region (0718, 4207)
SC: Paleoceanography and Paleoclimatology [PP]
MN: 2007 Fall Meeting