Department Seminar: Hélène Seroussi

Title: Can we better model ice sheets and their contribution to sea level rise?

Abstract: Over the past three decades, observations have shown that both the Antarctic and Greenland Ice Sheets have been losing mass at a fast pace. Glaciers and ice sheets have become today the largest contributors to sea level rise, but their contribution over the next century remains a key uncertainty in sea level rise projections. Understanding and reducing these uncertainties to improve the representation of past and future behavior of the ice sheets and their interactions with the other components of the Earth system remains scientifically and technically challenging.

I will start with a summary of the representation and inclusion of ice sheet simulations in sea level projections over the past few decades. Building on the latest results, I will use an ensemble of simulations of the Antarctic ice sheet over the 21st century to assess the role of dynamic mass loss of glaciers around the Antarctic Ice Sheet and investigate the different sources of errors and their relative role in ice sheet projections, both at continental scale and for some individual glaciers. I will then show how the exponential growth in the number of remote-sensing observations of the ice sheets over the last decade makes it possible to better study processes poorly represented in ice flow models, including through the use of data assimilation. The talk will conclude with some future research directions and new challenges.