Events

Speaker: Tyler Pelle, Green Postdoctoral Scholar, Scripps Institution of Oceanography

Host: Krista Soderlund

Title: From freshwater and saltwater: Investigating the 21st century evolution of the Aurora Subglacial Basin, East Antarctica, using coupled ice sheet modeling

Abstract: Recent studies have revealed the presence of a complex freshwater system underlying the Aurora Subglacial Basin (ASB), a region of East Antarctica that contains ~7 m of global sea level potential in ice that drains through thinning and retreating outlet glaciers. In many cases, this freshwater becomes channelized and flows hundreds of kilometers from the interior of the ice sheet to the coast, where it drains into ocean cavities underlying ice shelves that act to support these glaciers. Interaction of subglacial freshwater and oceanic saltwater can locally enhance ice shelf basal melting near critical grounding zones; however, contemporary ice sheet models have yet to account for these ice-ocean-subglacial hydrology interactions in century-scale projections due to both theoretical and computational limitations. In this talk, I will provide background on these coupled forcing processes and derive an efficient parameterization of ice shelf basal melting that resolves melt driven by both large-scale ocean circulation and localized subglacial discharge. I will then use this parameterization to execute coupled ice-ocean-subglacial hydrology model projections of a large sector of the ASB through 2100. In these projections, we find that subglacial freshwater interactions accelerate future retreat of ASB outlet glaciers and enhance their 2100 sea level contribution by up to 30% in high carbon emission scenarios, highlighting that Antarctic sea level assessments that do not take these interactions into account may be severely underestimating Antarctic Ice Sheet mass loss. Lastly, I will conclude with my vision for my future research plan and how I intend to utilize these numerical modeling techniques to supplement the wide breadth of polar and planetary research being conducted at UTIG.