Reconciling projections of the Antarctic contribution to sea level rise

Séminaire de Tamsin Edwards (The Open University, UK), mercredi 12 avril, salle Lliboutry, Bât. Molière

Abstract :
Two recent studies of the Antarctic contribution to sea level rise this century had best estimates that differed by an order of magnitude (around 10 cm by 2100 : Ritz et al., 2015 ; around 1 m : DeConto and Pollard, 2015). How are we to make sense of this apparent inconsistency ?
How much of the difference is due to different parameterisations of dynamic ice loss in these simple models (GRISLI and PISM), such as the ’cliff failure’ proposed in the latter paper, and how do these compare with a state-of-the-art high resolution model (BISICLES) ? How much is down to using satellite versus palaeodata to calibrate the model ? How much is due to the methodological choices in ensemble design and calibration ? Emulation - statistical modelling of numerical models - provides a powerful tool for performing sensitivity analysis of these studies, to understand these questions and more closely reconcile future projections for Antarctica.

Tamsin Edwards (The Open University, UK).