GRL paper on Thwaites Glacier
Abstract
The Amundsen Sea sector is experiencing the largest mass loss, glacier acceleration, and grounding line retreat in Antarctica. Enhanced intrusion of Circumpolar Deep Water onto the continental shelf has been proposed as the primary forcing mechanism for the retreat. Here we investigate the dynamics and evolution of Thwaites Glacier with a novel, fully coupled, ice-ocean numerical model. We obtain a significantly improved agreement with the observed pattern of glacial retreat using the coupled model. Coupled simulations over the coming decades indicate a continued mass loss at a sustained rate. Uncoupled simulations using a depth-dependent parameterization of sub-ice-shelf melt significantly overestimate the rate of grounding line retreat compared to the coupled model, as the parameterization does not capture the complexity of the ocean circulation associated with the formation of confined cavities during the retreat. Bed topography controls the pattern of grounding line retreat, while oceanic thermal forcing impacts the rate of grounding line retreat. The importance of oceanic forcing increases with time as Thwaites grounding line retreats farther inland.

Reference
H. Seroussi, Y. Nakayama, E. Larour, D. Menemenlis, M. Morlighem, E. Rignot, and A. Khazendar (2017), Continued retreat of Thwaites Glacier, West Antarctica, controlled by bed topography and ocean circulation, Geophys. Res. Lett., 44, doi:10.1002/2017GL072910.

Thwaites grounding line evolution
Evolution of grounding line position of Thwaites Glacier over 50 year simulations for (a) coupled ice-ocean model with 1992 ocean forcing (1992F), (b) coupled ice-ocean model forcing with warm ocean forcing (1992F+), and (c) standalone ice sheet model with parameterized ocean induced melting from 1992 (1992UC) experiments. Background shows the bed topography (m). The green and purple lines represent, respectively, the 1996 and 2011 observed grounding line positions [Rignot et al., 2014].