Glacier models have historically been used to understand glacier melt’s contribution to sea level rise. The capacity to project seasonal glacier runoff is a relatively recent development for these models. In this study we provide the first model intercomparison of runoff projections for the glacier evolution models capable of simulating future runoff globally. We compare model projections from 2000 to 2100 for all major river basins larger than 3000 km² with over 30 km² of initial glacier cover.

Liquid water can persist within old snow on glaciers and ice caps if it can percolate into the snow before it refreezes. Snow is a good insulator, and it is porous where the percolated water can be stored. If this happens, the water piles up and forms a groundwater-like system. Here, we show observations of such a groundwater-like system found in Svalbard. We demonstrate that it behaves like a groundwater system and use that to model the development of the water table from 1957 until the present day.