Understanding glacier processes to decode the drivers of glacier change

Detection, attribution and projection of glacier and ice-sheet change characterize much of our community’s work, motivated in part by the associated impacts ranging from local hazards to regional water supply to global sea-level rise. Toward improved attribution of glacier change on local to regional scales, I profile work aimed at discerning the internal versus external drivers of glacier behaviour through process-oriented studies. Using examples from northern Canada, combining observational and numerical approaches improves our understanding of fundamental processes that define the boundary conditions at the ice interface with bedrock, water and atmosphere. These studies have allowed us to revisit questions related to glacier surging, hydrology and ice-dammed lakes and the co-evolution of glacier geometry and thermal structure, with occasionally surprising and counter-intuitive results.

While the internal dynamics of glacier systems have the potential to confound the climate signal on societally relevant timescales, the direct effects of climate via surface mass balance remain as important as ever. Improved observational platforms, advances in modelling and the growing abundance and availability of remotely sensed data have amplified our capacity to study these systems, and more generously than ever reveal information archived by glacier processes. Using these tools, we are now beginning to disentangle the contributions of the geologic substrate, environmental setting, internal ice dynamics and climate forcing to observed glacier change in globally significant ice-rich parts of the world.