Discovery and science

Meltwater contributes to rising sea levels both directly, through runoff, and indirectly, by destabilizing and fracturing the polar ice cap. As part of his dissertation, Glenn Pitiot of the Institute of Environmental Geosciences (IGE) is studying the origin of this meltwater and its interaction with snow.

Observation at the Col du Lautaret

Good modeling, like a good recipe, depends first and foremost on good ingredients. The first step is therefore to identify them, and the Col du Lautaret provides an ideal testing ground for this. This winter, scientists from the IGE simulated the melting of the snowpack using dyes, which allowed them to understand how water flows through the snowpack. From the surface down to the base of the snowpack, water follows preferred paths and accumulates in certain areas. As it refreezes, the water forms layers of ice that in turn affect the flow. The goal was therefore to identify what was blocking the water at these different levels. To do this, the evolution of the mantle—from a dry state to a wet state—was monitored by tracing the origin of these ice layers.

Continued work at the North Pole and in the laboratory

An alpine snowpack, due to its thickness and the weather conditions it encounters, is very different from a polar snowpack. Building on their findings and the experiments conducted with the support of the Jardin at the Col du Lautaret, the researchers will spend the entire month of May in Spitsbergen, at Ny-Ålesund (79° North), with the goal of understanding the interaction between meltwater and a polar snowpack.

These two measurement campaigns will contribute to a “catalog” of phenomena that influence water flow within the snowpack. Next year, the IGE team plans to replicate these phenomena in the laboratory while controlling the key parameters. This will then enable them to develop calculation rules (parameterizations) that will be implemented in Météo-France’s Crocus snow model.