Polar ocean responses and feedbacks to a rapidly changing climate

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The Polar regions are key to Earth's climate system. Firstly, they are very sensitive to climate change. The Arctic, for example, has warmed twice as rapidly as the rest of the world in the past decades. Secondly, Polar areas stage ocean convection, a process where waters get very dense ("heavy") due to heat loss and sink to the deep ocean. When these water masses sink, they carry with them oxygen that will sustain life in the deeper parts of the ocean, and remove anthropogenic carbon from the atmosphere, reducing the greenhouse effect. The cold waters are then exported at depth to lower latitudes and are replaced by warm ("light") waters transported in the upper ocean from the tropics, creating a global ocean circulation that effectively transports heat from the equator to the Poles. This circulation, however, might lose its strength due to global warming. Rising ocean temperatures and constant influx of freshwater from melting glaciers, ice caps, and ice sheets make Polar waters less dense (since density depends mainly on temperature and salinity), and reduce their potential to sink and move this "conveyor belt". Besides the large-scale climatic consequences this might have, less dense waters also affect sea ice cover, marine productivity, and ocean circulation at regional scales, all of which are intimately connected to Northern Canadian communities' practices. Moreover, as glaciers increase their discharge, more icebergs are formed, directly impacting navigation and other offshore activities. Therefore, the present research program proposes to assess the consequences of ocean warming and freshwater influx to the Polar oceans, with focus on the Arctic, Baffin Bay, Hudson Bay, Canadian Arctic Archipelago, and the Subpolar North Atlantic. Together with my HQP, we will use computer models, combined with field observations, to understand changes in ocean circulation, sea ice cover, presence of icebergs, nutrient availability for marine life and carbon sequestering from the atmosphere to the north and east of Canada. By improving the understanding of the impacts of climate change in Polar oceans and their response back to climate, this program will help Northern communities that rely on hunting and fishing, economic and military activities that depend on marine transportation, and policy-making by improving predictions of the ocean state in the near future. As I start my career as an independent researcher, I will strive not only to develop excellent science but to help forming highly-qualified scientists and human beings. Besides scientific training, I will guide my HQP towards a respectful workplace, where diversity is not only accepted but celebrated. Outreach will also play an important role in my research program, exposing children from a diverse background to the field of ocean sciences and showing that anyone can be a scientist.