Local forcing mechanisms challenge parameterizations of ocean thermal forcing for Greenland tidewater glaciers

Local fjord-scale processes significantly modify ocean thermal forcing at Greenland tidewater glaciers, challenging the accuracy of current large-scale ice sheet models. Research using idealized simulations found that bathymetric obstructions and iceberg submarine melting can alter near-glacier thermal forcing by up to 3°C, despite identical ocean boundary conditions. A common adjustment for fjord bathymetry allowed predictions within 0.2°C, while new parameterizations accounting for iceberg-driven cooling accurately replicated interior fjord thermal profiles in simulations and observations from Ilulissat Icefjord. This study highlights the need for refined models to incorporate these local mechanisms, improving predictions of Greenland Ice Sheet mass loss.

Hager, A. O., Sutherland, D. A., & Slater, D. A. (2024). Local forcing mechanisms challenge parameterizations of ocean thermal forcing for Greenland tidewater glaciers. The Cryosphere, 18(2), 911–932. https://doi.org/10.5194/tc-18-911-2024