Introduction
The project “International Polar year: Natural climate variability and forcings in Canadian Arctic and Arctic Ocean” is funded by the Natural and Engineering Research Council of Canada (NSERC) and aims at understanding and reconstructing the evolution of climatic and oceanic conditions over the last ~10 millennia, which corresponds to the most recent geological period called Holocene. The study of sea surface conditions during this recent geological time period provides us with important information on natural climate variability and cycles in the World Ocean. It is part of the 2007-2008 International Polar Year effort to study and document the climate of Arctic regions.
Our understanding of the different forcings responsible for energy transfers between the Equator and the Poles and between the oceans and atmosphere are still poorly understood. The factors regulating the actual climate system are relatively well understood, while those acting at longer time scales (centuries to millennia) remain unclear. This lack of understanding is mainly due to the fact that instrumental measurements of atmospheric and oceanographic variables are only available for the last 120 to 130 years at the most. When it becomes necessary to study climate variability and cycles over longer periods of time, we need to turn towards the geological archives preserved in continental and marine sediments. Marine sediments have the advantage of accumulating on the seafloor more or less without interruption, while sediments on land are often scarce and incomplete. One exception is the ice caps, such as the Greenland and Antarctic ice caps, where atmospheric and climatic conditions are recorded without interruption for hundreds of thousands of years.
Therefore, it is in the geological archives preserved in lake and oceanic sediments that researchers from our team will seek out the necessary information for understanding the evolution of climatic conditions in arctic regions over the last 10,000 years.