Subventions et des contributions :

Subvention ou bourse octroyée s'appliquant à plus d'un exercice financier. (2017-2018 à 2022-2023)

Climate warming in the Arctic is outpacing the rest of the planet, and the profound environmental change underway will amplify warming trends with global impacts. Understanding Arctic climate and landscape evolution is critical so that future changes can be predicted and used to guide sound policy decisions for northern communities and natural resources.
The climate history of the Canadian Arctic is not well understood. Past climate data offer valuable insights on climate dynamics, but Arctic historical records are sparse and short. Lakes are abundant in northern landscapes and their sediments are sensitive archives of past environmental changes that provide compelling evidence for what a future, warmer world might look.

The proposed research program will apply a rigorous paleolimnological approach to place instrumental records into a long-term perspective and fill long-standing knowledge gaps on climate and environmental change in one of the most inaccessible regions of Canada’s North. Using multiple proxies for reconstructions of past temperature and other environmental variables, my research team will study biostratigraphic and geochemical records preserved in the sediments of Nettilling Lake, the largest freshwater watershed in the Arctic Archipelago, as well as in lakes of the surrounding Foxe Basin. The paleoclimate proxy data generated will be synthesized to allow regional comparisons with ice core data from Baffin Island and Greenland and with regional paleoceanographic data. Surficial landforms will be mapped and dated using radiocarbon and exposure techniques to determine the position and timing of glacier retreat and past sea/lake level changes. Multi-sensor core loggers will provide high resolution analyses of sediment geochemistry and magnetic susceptibility, with core chronology established using radiometric and paleomagnetic dating.

We will test d18O of various siliceous microfossils as a new proxy for tracking past changes in temperature, salinity, currents and thermal structure to elucidate paleohydrological gateways and connections during the early history of the Nettilling Lake basin. We aim to provide new insights into how these proxy-based signals are controlled by atmospheric circulation modes associated with past climate changes, with implications for modelling ecosystems under future climate scenarios.
The proposed research will assess critical thresholds intrinsic to the Arctic climate system and address fundamental questions about Holocene climate variability and sensitivity, as well as postglacial glacio-isostatic dynamics. These insights will greatly improve our ability to anticipate future changes and impacts on northern communities and infrastructure. The historical baseline conditions established through this research will help develop policies for adaptation to a rapidly changing climate and modernization of Canada's North.