Why does clean snow melt more slowly than dirty slow?

Answer 1

This is due to the principle of albedo. Snow is among the brightest natural surfaces on earth, and therefore reflects most incoming solar radiation. If the radiation is reflected, it cannot be absorbed by the surface and converted to thermal energy (heat) to raise the temperature. When you add any type of dirt and impurities to the snow, you are lowering the albedo of the snow, causing the surface to absorb more radiation and heat up. This causes the snow to melt faster.

Interestingly, if the snow is covered by more than about a centimeter of dirt, it will be insulated from the sun and melt more slowly.

Answer 2

The amount of time required for a pile of snow to melt is proportional to the amount of snow. This is because a bigger pile of snow needs more amount of heat to melt. A smaller pile can get enough heat in a short period of time. So next time you make a snowman, make sure you make a huge one, so that he stays with you for a longer period of time ;-)

Answer 3

It piles up because when the snow sticks to the ground when it is lower than about 32 degress, the snow keeps piling on the snow that is already stuck or frozen to the ground. Snow(and sand) are blown by winds. The winds can carry the snow until the wind either slows down or changes direction. This usually happens at the edge of a hill or where there is an obstruction, such as a house. When the wind goes over the hill the area is greater and the wind speed drops, thus dumping the snow. Drifts form at ridges and next to houses or snow fences.

Answer 4

White, clean snow reflects a lot of the Sun's rays that fall on it in the form of heat, so it heats slower and therefore melts slower. Anything black or dark, like dirty snow absorbs a lot of the Sun's rays in the form of heat, so it heats faster and therefore melts faster.