Projections of future climate suggest that high latitudes of the Northern Hemisphere will experience a larger environmental response than the global mean. Arctic regions are already characterized by an acceleration of climatic and environmental change. Loss of sea ice and melting of continental ice caps are dramatic and the rate of change unprecedented.
This is particularly critical since climate change in the Arctic can trigger a series of feedback processes affecting the global climate. Firstly, the accelerated loss of the Greenland ice mass in response to atmospheric and oceanic warming may lead to a significant increase in global sea level.
Also, the Arctic sea-ice cover directly impacts the Earth's heat budget through albedo and freshwater export. The excess meltwater routed towards the North Atlantic and Labrador Sea may interfere with the formation of deep ocean water and the strength of the Atlantic meridional overturning circulation (AMOC), thus affecting the global ocean circulation.
Forecasting the evolution of the Arctic-subarctic ecosystem is thus of utmost importance, not only for sustainable development of high latitude regions, but also for the prediction of global sea-level and climate changes. Such predictions will in turn help stakeholders in the mitigation and adaptation process for human populations and communities that are most at risk. The feedback processes that link the Arctic ice, the ocean and atmosphere, however, remain incompletely documented from observations and are imperfectly quantified as state-of-the-art climate models still fail to reproduce observed instrumental trends of Arctic ice decline. One way of getting around these issues is to use paleoceanographic data so as to extend observations from physical oceanography beyond the instrumental records. Such approaches can help to assess the natural variability of the ocean circulation and weigh the actual impact of anthropogenically driven global warming.
The goals of ArcTrain are thus i) to better understand interactions between ice, land and the ocean in the Arctic-subarctic domain, on time scales ranging from seasons to millennia, ii) to provide benchmarks for current trends and iii) to evaluate the ability of climate models to assess the impact of climate changes on Arctic-subarctic environments, mostly based on synopses of warmer climate intervals in the past. The overall research program will be conducted through sub-projects grouped in three interconnected areas: sea ice, ocean circulation and ice sheets. For each topic, investigation of processes, feedbacks and variability will combine observational data, reconstructions from proxies and modelling. The study areas, which focus on the eastern Canadian Arctic, Baffin Bay, Labrador Sea and Greenland Sea.