Madeleine Youngs - SMSP Spring Seminar Series 2025

"Ice Shelf Melt Feedbacks in the Southern Ocean"

Madeleine Youngs

Assistant Professor

University of Maryland, College Park

February 28, 2025 at 12:00 PM

Robinson 202 + via Zoom in Cannon 203

Hosted by Carlos Moffat

Abstract: Ice shelf melt in Antarctica is the largest potential contributor to future sea level rise over the next century. However, the interplay between the melt and the surrounding circulation is not captured in many climate model simulations. In higher-resolution regional studies, this interplay has been quantified, but lacks a circumpolar assessment. This study addresses this using a 1/3 degree MITgcm circumpolar ocean model coupled to interactive thermodynamic ice shelves forced with both preindustrial and future warming scenarios, and a hybrid fixed-stratification experiment. These three runs permit a quantification and partitioning of the total climate response into the forced response and meltwater feedbacks. This study partitions the response of the ice shelves into two categories, dense shelf water formation regions, and westward -- downstream along the Antarctic Slope Current -- of these formation regions. The dense shelf water formation regions experience a positive feedback, where ice shelf melt begets more ice shelf melt. Westward of these formation regions, the enhanced ice shelf melt is transported downstream preventing the intrusion of circumpolar deep water into the ice shelf cavities, a negative feedback. This work highlights the importance of resolving coastal Antarctica to predict future climate change.