Abstract

NB!!!! if you wish to attend and are external to BAS please let the organisers know ahead of time so they can let you in at reception

Hello everyone,

Next up in the Polar Oceans Seminar Series we have a talk from Bethan Wynne-Cattanach from the University of Cambridge, presenting at 2pm on the 19th of November 2025 in Seminar Room 1 on Large-eddy simulations of the ice-shelf-ocean boundary layer beneath basal terraces.

Abstract: Ocean-driven melting at the base of ice shelves is a primary driver in the acceleration of the flow of grounded ice into the ocean, leading to sea level rise. Observations have shown that basal topography beneath rapidly melting ice shelves in warm cavities is complicated, including topographic features such as terraces which are large enough to disrupt the ice-ocean boundary layer and control melt rate. However, these features are too small to be resolved in large-scale climate models, and our current understanding from observations is limited. To address this, we use 3-dimensional, turbulence permitting large-eddy simulations of the ice-ocean boundary layer to examine the influence of basal terraces on ocean turbulence and ice melt. We implement the basal topography using an immersed boundary method and the size of the terrace is chosen to be representative of those observed within an ice base channel of Pine Island Glacier Ice Shelf. We focus on the dynamics driven by the buoyant melt water plume along the terrace, and vary the height of the terrace relative to the boundary layer thickness to investigate different flow regimes.

Feeling fintastic about this, Kat and Nico