We present the PROMICE ice-velocity dataset, a time series of maps showing how fast the Greenland Ice Sheet flows. The time series is created using satellite radar images from Sentinel-1 since 2016 and is updated with a new map every 12 days providing a detailed view of ice sheet wide dynamics for more than a decade. Continuous updates and improvements, such as those presented here, are essential for maintaining long, consistent, high-quality records of key climate variables for research.

Light-absorbing particles (LAPs) are often present as a mixture on snow surfaces and are important to disentangle because their darkening effects vary but also because the processes governing their presence and accumulation on snow surfaces are different. This study presents a novel method to retrieve the concentration and albedo-reducing effect of different LAPs present at the snow surface from surface spectral albedo. The method is then successfully applied to ground observations on seasonal snow.

This study on Glacier de la Plaine Morte in Switzerland employs various passive seismic analysis methods to identify complex hydraulic behaviours at the ice–bedrock interface. In 4 months of seismic records, we detect spatio-temporal variations in the glacier's basal interface, following the drainage of an ice-marginal lake. We identify a low-velocity layer, whose properties are determined using modelling techniques. This low-velocity layer results from temporary water storage subglacially.

Glacier ice often contains liquid water. How much exactly depends on the history of ice formation, the internal heat sources, and on the drainage pathways between ice crystals. The liquid water content strongly influences many properties of the ice, such as its softness. We measured in two glacier caves the water content directly in the ice walls by cooling the ice. Water contents of 1–2 % were found, which agrees with previous measurements.

This study presents a database compiling 95 ice temperature profiles from the Greenland ice sheet and peripheral ice caps. Ice viscosity and hence ice flow are highly sensitive to ice temperature. To highlight the value of the database in evaluating ice flow simulations, profiles from the Greenland ice sheet are compared to a modeled temperature field. Reoccurring discrepancies between modeled and observed temperatures provide insight on the difficulties faced when simulating ice temperatures.