1. Fresh, undisturbed snow is composed of a high percentage of air trapped among the lattice structure of the accumulated snow crystals. Fresh, uncompacted snow that falls at close to 32 degrees F and is accompanied by relatively strong winds typically has how much trapped air? .

a) 20-30 percent   b) 60-70 percent   c) 90-95 percent.

2. Water and ice are colorless so why is snow white, and sometimes even appears blue?

The water content of snow is more variable than most people realize. While many snows that fall at temperatures close to 0 degrees C and snows accompanied by strong winds do contain approximately one inch of water per ten inches of snowfall, the ratio is not generally accurate. Ten inches of fresh snow can contain as little as 0.10 inches of water up to 4 inches depending on crystal structure, wind speed, temperature, and other factors.

2. Water and ice are transparent and light passes through without any portions of the visible spectrum being absorbed or reflected. On the other hand, most of the visible (white) light striking a snowy surface is reflected back by the countless tiny surfaces of the snow crystals giving snow its white appearance.

One can think of the ice or snow layer as a filter. If it is only about a centimeter thick, all the light makes it through and it is seen as white, but if it is a meter or more thick, mostly blue light makes it through. More red light is absorbed compared to blue. Not much more, but enough that over a considerable distance, say a meter or more, the light emerging from the snow layer tends to be made up of more blue than red light. Poking a hole in the snow and looking down into the hole you can see blue light or the blue color associated with the depths of crevasses in glaciers. In each case the blue light is the product of a relatively long travel path through the snow or ice.