[1] We obtained quantitative multivariate data from each varve of a minerogenic lacustrine sequence from the Canadian High Arctic, using an image analysis technique applied to thin-sections. The information on each varve from the uppermost core section was compared with a 35 yr meteorological dataset. Snowmelt intensity, which is an index reflecting the energy available for sediment transport, correlates well with the median grain-size measured for each varve, as well as with the weight of the 10-20 and 20-60 mm fractions. The proportion of fine silt also correlates with low intensity summer precipitation. This methodology allows us to decipher the climatic control on sedimentary processes and yield a new perspective for constructing models which link climate to sediments that contain few biological remains. This model can then be used to infer paleoclimate with annual resolution from the downcore grain-size analysis.
where changes are expected to be most extensive, so we need to place these projected changes in the context of past Arctic climate variability. We know, from large-scale studies of climate variability over the last century and the last millennium, and from model simulations, that temperature changes tend to be amplified at high latitudes-and this seems to be true both for the periods of 'natural' and of anthropogenic forcing (Moritz et al., 2002; Holland and Bitz, 2003; Arctic Climate Impacts Assessment (ACIA), 2005; see also the discussion at http://www.realclimate.org/index.php?p=234, last accessed 19 October 2007). Palaeoclimatic records from high latitudes may thus capture changes that have affected the hemisphere as a whole, whereas the record is more muted at lower latitudes. This polar amplification is related to feedbacks associated with
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