Modeling Ice-shelf Ocean Interaction at Petermann Glacier, Greenland

Abstract

Petermann Glacier drains about 4% of the Greenland ice sheet area, with at least 80% of its mass loss through basal melting of the floating ice shelf. Utilizing a high-resolution coupled ice-shelf-ocean model, we aim at understanding the ocean circulation in Nares Strait and the mechanism of oceanic heat supply below the ice shelf as well as quantifying the basal mass loss. The numerical model is based on the Finite-Volume Community Ocean Model (FVCOM), taking advantage of its flexible spatial resolution that can follow the topography. A regional model domain has been set up, which spans the greater Nares Strait region and covers Petermann Fjord with 200-m horizontal resolution and includes the Petermann Glacier geometry. As a first step, we focus on the role of tides for transporting ocean water into the ice-shelf cavity. Tidal simulations are validated with available observations, demonstrating the capability of FVCOM in reproducing the tidal current pattern in Nares Strait. Lagrangian particle trajectories are computed to explore the water exchange in Petermann Fjord. It is found that tidal oscillations in Nares Strait lead to a residual circulation in the fjord and inside the ice-shelf cavity. These results suggest that tidal dynamics plays an important role in modulating regional circulation in Petermann Fjord and heat transport to Petermann Ice Shelf.