Depth hoar formation

Figure 3 Measured snow SSA profiles in central Alaska in two different snowpacks a natural snowpack on the ground, where a strong temperature gradient led to depth hoar formation (HGM snowpack) and the same snowpack on Tables, under which the air circulation prevented the establishment of a significant temperature gradient (QIM snowpack). (a) comparison of the QIM snowpack of 16 February with the HGM snowpack sampled 8 days before and 10 days after (b) comparison of both snowpacks sampled just 4 days apart. In both cases the SSA is much higher in the QIM snowpack. Typical snowpacks heights were 50 cm for HGM and 40 cm for QIM.

Climate change will modify kr values in complex ways. Warming will limit depth hoar formation, increasing kj More frequent melting events in temperate climates will form ice layers with high kr values. In contrast, the growth of shrubs on the tundra will limit the effect of wind, transforming windpacks into depth hoar of much lower values. 

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