Geomorphological controls on the persistence and extent of Landfast Sea Ice in James Bay Region

Bathymetry plays a critical role in determining the occurrence and stability of landfast sea ice, although its seasonal impact on sub-Arctic ice-covered shelves has yet to be thoroughly quantified and understood. Our study explores the ways in which nearshore bathymetry and coastal topography influence the spatial distribution, seasonal persistence, and variability of landfast sea ice, with an emphasis on shallow embayments of James Bay. Our hypothesis suggests that factors like coastal orientation and bathymetry provide extent and stability to the landfast sea ice in the James Bay region, rather than being exclusively governed by marine and atmospheric factors. Using satellite-derived observations of landfast sea-ice delineations, regional bathymetric datasets, and information on coastal geomorphological configuration, this analysis will quantify statistical relationships among the landfast-ice edge extent and persistence metrics with the bathymetric thresholds and coastal orientations. Initial findings indicate that recurrent landfast ice extents are larger and their persistence is higher when there is a shallow water column, undulating bathymetry with mounds, and/or offshore features. Our observations support the hypothesis that bathymetry plays a crucial role in determining the presence and stability of landfast sea ice. By explicitly correlating bathymetry and geomorphology with landfast ice phenology and stability indicators, our research aims to advance both conceptual and quantitative understandings within coastal ice modelling frameworks and refine projections concerning the response of landfast sea ice to ongoing Arctic amplification and climate change.