Subventions et des contributions :

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

Despite the well-documented warming trend in Arctic climate and a corresponding increase in permafrost temperatures there remains tremendous uncertainty about the response of continuous permafrost systems to climate change. Several model-based studies suggest widespread terrain instability, melting and disappearance of permafrost, while recent field-based studies indicate that permafrost systems may be more resilient than modelling scenarios imply. Generalizations concerning permafrost response to climate change can result in errors in estimates of carbon flux, landscape change and infrastructure problems. There is an urgent need for empirical observation of heat and moisture fluxes for the active layer and the upper part of permafrost to better constrain modeling activities.
The primary goal of this research is to assess the vulnerability of key high Arctic permafrost systems to climate change by focusing on thermodynamic processes in the active layer and at the active layer permafrost interface.

Field sites on Ellesmere and Axel Heiberg Islands will include areas characterized by ice wedge systems, wetlands, and tundra landscapes underlain by ground ice.

Methods By making detailed measurements of boundary layer climate, surface temperature, temperatures, and mass and energy fluxes through the active layer and at the permafrost table coupled with observations on seasonal snow depth and distribution, vegetation, and local topographic changes for specific geo-ecosystems this research will contribute a better understanding about the dynamic relationship between climate inputs and permafrost response. By looking at permafrost as a complex adaptive system this study will identify various feedback processes that contribute to system resiliency and potential tipping points. It is well understood that once widespread thermokarst begins permafrost systems become highly unstable and the normal self regulating processes often require decades to re-establish a new equilibrium. By coupling measurements of CO 2 and CH 4 flux to these observations this study not only defines the thresholds of change but potential feedbacks to the climate system.

Applied research This study will assess the potential impact of changing active layer conditions on contaminated soils. There are many sites throughout the high Arctic of past and present fuel storage in steel drums that are notorious for leaking and fuel transfer processes that lead to spills. This study will assess the extent of residual contamination and potential remobilization of contaminants under scenarios of increased active layer depth and melting ground ice. This research involves the use of a wide range in research tools; in addition to site specific monitoring systems and subsurface mapping tools like GPR and Resistivity this research will use an unmanned aerial vehicle (UAV) to map small scale changes and identify thaw hotspots.