Progress toward globally complete frontal ablation estimates of marine-terminating glaciers
William Kochtitzky, Luke Copland, Wesley Van Wychen, Regine Hock, David R. Rounce, Hester Jiskoot, T. A. Scambos, Mathieu Morlighem, Michalea D. King, Leo Cha, L. M. Gould, Paige-Marie Merrill, A. F. Glazovsky, Romain Hugonnet, Tazio Strozzi, Brice Noël, Francisco Navarro, Romain Millan, Julian A. Dowdeswell, Alison Cook, Abigail Dalton, Shfaqat Abbas Khan, Jacek Jania
Abstract
Abstract Knowledge of frontal ablation from marine-terminating glaciers (i.e., mass lost at the calving face) is critical for constraining glacier mass balance, improving projections of mass change, and identifying the processes that govern frontal mass loss. Here, we discuss the challenges involved in computing frontal ablation and the unique issues pertaining to both glaciers and ice sheets. Frontal ablation estimates require numerous datasets, including glacier terminus area change, thickness, surface velocity, density, and climatic mass balance. Observations and models of these variables have improved over the past decade, but significant gaps and regional discrepancies remain, and better quantification of temporal variability in frontal ablation is needed. Despite major advances in satellite-derived large-scale datasets, large uncertainties remain with respect to ice thickness, depth-averaged velocities, and the bulk density of glacier ice close to calving termini or grounding lines. We suggest ways in which we can move toward globally complete frontal ablation estimates, highlighting areas where we need improved datasets and increased collaboration.