Fig. 6: Snowpack contrasting states found along the transect.

Winter snowpack covers the study region for 6 to 10 months of the year. Snowpack contrasting states are described based on the depth of snow and snowpack stratigraphy, describing ice crystal type, grain size and hardness of the different snow layers of the snowpack in a landscape (30 |× 30 km) characterized by a flat terrain (see Supplementary Note 1 for definitions). Along the transect, the snowpack ranges from a two-layer poorly insulating, thin, hard and dense polar desert snowpack to a multi-layer, very thick and insulating boreal forest snowpack.