Sankey diagrams are used to visualize the simulated sea ice and snow-on-ice mass budgets across Arctic and Antarctic sea ice, based on CMIP6-class models and an atmosphere-forced ocean–sea ice simulation. Coupled models and the forced run show a similar relative budget, with more basal growth and surface melt in the Arctic and a larger snow-to-ice contribution in the Southern Ocean. The diagrams are a model-based reference intended to support the upcoming IPCC AR7.

Crevasses are deep cracks in glacier ice that route water to the glacier bed and endanger travel, yet are rarely mapped regionally. We trained a machine-learning model on satellite data to map visible crevasses on all Svalbard glaciers each year from 2017 to 2025. Three in four glaciers with a clear trend lost crevasses in their lower parts, yet the total area grew, likely as thinning snow cover exposed crevasses higher up. Yearly maps can help detect glacier surges and plan safe travel routes.

Mountain snow stores water for millions of people, but no satellite yet maps how much water it holds. The new NISAR radar satellite may be able to, because its signal slows down as it passes through snow. We tested this over a mountain site in Idaho by comparing the satellite measurement of new snow with maps of snow depth change from an airplane-mounted laser scanner. The two agreed well, especially in open terrain, giving the first evidence that NISAR can measure snowfall from space.

Extreme precipitation shapes hazards and water resources in high mountains, but is rarely observed directly. On 4 October 2025, weather stations on Mt. Everest recorded one of the most extreme snowfall events ever measured. The storm revealed that Himalayan snowfall extremes can be far larger than previously documented, and that intense snowfall can cool the atmosphere sufficiently to prevent rain at impact-sensitive elevations, complicating the picture of how warming will affect future storms.

Using frequent high-resolution satellite images, we reconstructed repeated drainage from lakes on the surface of Purepu Glacier in 2023 and 2025. The lakes reached similar sizes before drainage, but the 2025 event released much more water and left substantial residual water into 2026. The results show that lake area alone cannot describe drainage hazard and support intensive monitoring during early to mid-July 2026.

The last two glaciers in Slovenia are just disappearing. In 2023, ice cores were taken from Triglav and Skuta Glacier to determine, as a first and maybe the last attempt, the age of ice. At Triglav, the net accumulation is negative since the early 1960s, while ice below 1 m is older than 70 years. Skuta Glacier shows similar patterns. Today, Triglav Glacier has nearly disappeared and Skuta Glacier continues to shrink despite its more sheltered location.

Ice cores can preserve past climate information in layers, but melting or cutting samples for measurements can mix or blur that information. We tested femtosecond laser ablation, a method that removes material with ultrashort laser pulses, to sample ice directly in a cold laboratory. It made repeatable craters less than 0.2 millimeters wide, spaced 0.5 millimeters apart. This could support studies of very old ice cores, where layers are very thin, while leaving most of the sample intact.

Understanding past iceberg activity during the Quaternary is key to constraining ice‑sheet dynamics and freshwater release during melting. We document ice‑rafted dropstones dredged at 36° N on the Mid‑Atlantic Ridge that form a calc‑alkaline magmatic series and yield ages of ~1700–1630 Ma. This indicates derivation from the Labradorian arc‑accretion orogeny in eastern Canada, implying a source in the Gulf of Saint Lawrence that favored southward iceberg transport to lower latitudes.

We developed a new system to map and monitor snow and stored water across large mountain regions using satellite data and computer simulations. Tested in four major European river basins, the system reproduced snow conditions with high accuracy and realistically captured how snow changes with elevation. Because it does not rely on ground measurements, it can help provide consistent information on snow-water resources worldwide, supporting water management and climate adaptation.

This study compares the grounding line positions derived from COSMO SkyMed InSAR and ICESat-2 data over Antarctica. Three grounding zone indicators, F, I_b, and H, are evaluated against the DInSAR grounding line across 73 glaciers. Mean offsets are 177 ± 325 m (F), 40 ± 830 m (I_b), and 4508 ± 2731 m (H). Results show unexpected ordering (F > I_b), highlighting inconsistencies and the need for cross-validation in grounding line mapping.