High-resolution pre-industrial evolution of sea surface conditions in the Canadian Arctic

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Global warming caused by the anthropogenic release of greenhouse gases is now a fact, as stated in the 2007 report of the Intergovernmental Panel on Climate change: "Warming of the climate system is unequivocal, as is now evident from observations of increases in global average air and ocean temperatures, widespread melting of snow and ice and rising global average sea level". The best example is the extent of Arctic sea ice in 2007, which was the lowest ever recorded. The Arctic ecosystems and northern communities are the most affected by such changes. Therefore, there is a pressing need to develop realistic and accurate climate scenarios for decision makers to implement adaptation and mitigation measures. The main objective of our research program is to quantitatively reconstruct the evolution of sea surface conditions throughout the Canadian Arctic for the last 300-400 years (Pre-Industrial/ Industrial Era transition) in order to provide climate modelers with the necessary boundary conditions to test the accuracy of the next generation of regional climate models for the Arctic. The quantitative reconstruction of sea surface temperature, salinity and duration of sea ice cover will be realized at a pluri-annual time resolution using dinoflagellate cyst assemblages as proxy indicators. Plankton (motile dinoflagellate assemblages) and surface sediment samples (dinoflagellate cyst assemblages) will also be analyzed and compared to assess the threat of invasive aquatic species and/or harmful algal outbreak that may result from increasing water temperature and increased shipping traffic through the Northwest Passage following the disappearance of sea ice on a seasonal basis. These results will help decision makers to adapt the Canadian regulation on ship ballast disposal and mitigation.