SNOW PHENOMENA

1. Snowballs in the Canadian Arctic:

Snowballs (rollers) form in specific weather and snow conditions: gusty wind, mild temperature (0-3C), a crust on the snowpack surface, and big snowflakes.  Under these conditions, when a big snowflake reaches the snow surface, it catches some snowflakes and jumps over a short distance of 10 to 50cm. When it lands, it again catches more material, and jumps another time.  After a series of jumps over a distance of perhaps 5 meters, it becomes too heavy to jump and it starts to roll on the snow surface.  The rolling (over a distance of up to 10 meters) creates the snow roller structure. Large snow roller of 42cm in diameter was found in Finland and the biggest roller was reported to be 1.5m in diameter.
 

2. Dirty snow patches in the Canadian Arctic:

A dirty snow patch is a mixture of snow and dust due to wind drifting in winter. The albedo (ratio of reflected/incoming radiation) of a dirty snow patch is very low in comparison to clean snow, it receives more radiation and melts earlier in spring.
 

3. Ice columns in the snowpack in the Canadian boreal forest

Ice columns can be found in the snowpack under trees in early spring, when snow intercepted by tree branches melts at near freezing temperatures. The intercepted snow may retain a maximum liquid water content of about 15% by mass, meltwater in excess of this limit drips from the canopy, infiltrates and refreezes in the cold snowpack forming ice columns.  Ice columns also exist in snowpack in non-forest regions, due to “finger flow” (preferred vertical path for meltwater movement) and meltwater refreezing in snowpack.