Inverse Level-set Problems for Capturing Calving Fronts

Abstract

Capturing the calving front motion is critical for simulations of ice sheets and ice shelves. Multiple physical processes - besides calving also melting and the forward movement of the ice - need to be understood to accurately model the front. Calving is particularly challenging due to its discontinuous nature and modelers require more tools to examine it. A common technique for capturing the front in ice simulations is the Level-set method. The front is represented implicitly by the zero isoline of a function. The movement of the front is described by an advection equation, where the velocity field is a combination of ice velocity and frontal ablation rate. To improve understanding of these processes, we are developing methods to estimate parameters of calving laws based on inverse Level-Set problems. The regularization is chosen so it can handle discontinuous parameters or calving laws to fit discontinuous front positions due to large calving events. The input for the inverse problem is formed by observational data from satellite images that is often sparse. The methods will be applied to large scale models of the Antarctic Ice Sheet.