Modelling the Oceanic Advection of Pollutants Spilt Along with the Northwest Passage

The Arctic sea ice is dramatically retreating in concentration, thickness, and duration. The larger and longer-lasting periods of open water will likely lead to increase trans-Arctic ship traffic, which then increases the risk of accidents and of pollutant spills. In this study, we focus on the potential oceanic circulation pathways of pollutants that may be spilt along with the Northwest Passage in the Canadian Arctic. We used a high-resolution numerical model and a Lagrangian particle tracking tool to simulate the advection of pollutants released in and within proximity to the Canadian Arctic Archipelago. We released 5000 virtual particles over 24 main release sites every 10 days during the operating season (June-October) for 12 years (2004-2015). For each simulation, we examined the circulation pathway and computed particles' spreading area, distances travelled, subsurface spread, and the variability and uncertainty of their distribution during the two-year simulation duration. We analysed these factors with respect to the dominant oceanic circulation of where the particles were initially seeded and the role of atmospheric circulation and were able to identify three main circulation regimes and eight small-scale regimes. This study highlights the role of oceanic advection in the spreading of particles and determines that particles released in the eastern study area exhibited the largest spreading area as the majority propagated into the North Atlantic Ocean rapidly.

Automated summary

The retreat of Arctic sea ice has led to increased risks of trans-Arctic ship traffic and pollutant spills. This study used numerical modeling and particle tracking to investigate the oceanic circulation pathways of pollutants in the Canadian Arctic. The results identified the eastern study area as having the largest spreading area for released particles, with most of them propagating into the North Atlantic Ocean.