Atmosphere Ocean Science Colloquium

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Oceanic melting of Antarctic glaciers: does the tail wag the dog?

Speaker: Andrew Stewart, University of California, Los Angeles

Location: Warren Weaver Hall 1302

Date: Wednesday, May 7, 2025, 3:30 p.m.

Synopsis:

Oceanic melting of Antarctic ice shelves is a key component of the mass balance of the Antarctic ice sheet, and exerts global influence on climate via its connections to sea level and deep water formation. Previous work has emphasized the role of atmospheric variability in driving  changes in warm water access to the bases of the ice shelves, and thus in controlling ice shelf melt rates and triggering glacial retreat. Yet the input of meltwater to the ocean also serves as a forcing of the circulation, raising the prospect of feedbacks between the melting of Antarctica's ice shelves and the current systems that deliver heat to their bases. In this talk I will present results from a hierarchy of numerical modeling and first-principles theoretical approaches that quantify the importance of this meltwater feedback, identify the dynamical mechanisms via which it operates, and formulate predictive theory that incorporates its effects. I will further discuss ongoing work via which these theoretical insights may be translated into parameterizations to allow representation of melt-circulation feedbacks in future climate projections.