What is the global glacier ice volume outside the ice sheets?

作者：Regine Hock, Fabien Maussion, Ben Marzeion, Sophie Nowicki · 发表于：Journal of Glaciology · 年份：2023 · DOI：10.1017/jog.2023.1 · 被引用次数：35 · 研究领域：Cryospheric studies and observations、Climate change and permafrost、Arctic and Antarctic ice dynamics

Abstract A recent study (Millan and others, 2022a, Nature Geoscience 15(2), 124–129) claims that ice volume contained in all glaciers outside the ice sheets and its potential contribution to sea level is 20% less than previously estimated. However, the apparent decrease is largely due to differences in choice of domain, as the study excludes 80% of the glacier area in the Antarctic periphery that was included in previous global glacier volume estimates. The issue highlights the difficulty in separating glaciers from the ice-sheet proper, especially in Antarctica, and the need for both the glacier and ice-sheet communities to develop standards and protocols to avoid double-counting in global ice volume and mass-change assessments and projections. Process-based inversion models have replaced earlier scaling methods, but large uncertainties in global glacier volume estimation remain due to the ill-posed nature of the inversion problem and poorly constrained parameters emphasizing the need for more direct ice thickness observations.