MORE ABOUT SNOW
            Snow falls. We look out at the snow, bundle up and venture out to remove snow from sidewalks and streets, and make our way to places where we think we must be. Year around researchers and scientists who go exploring and collecting data  about snow and ice in the frozen part of our Earth’s system.
            One such group of scientists staff the National Snow and Ice Data Center related to the University of Colorado at Boulder. The research from the NSIDC reveals some interesting facts about snow.       
Snow is a good insulator. Fresh, undisturbed snow is composed of a high percentage of air trapped among the lattice structure of the accumulated snow crystals. Since the air can barely move, heat transfer is greatly reduced. Fresh, uncompacted snow typically is 90-95 percent trapped air.
Snow in wilderness areas is edible and safe. Clean snow, away from urban areas where it may contain pollutants, is certainly edible. Sometimes snow contains algae which gives it a red color. This snow is safe to eat.
Not all snow is the same temperature. The air temperature controls the temperature at the surface of the snow. “The colder the air above, the colder the snow layers near the surface will be, especially within the top 12 to 18 inches. Snow near the ground in deeper snow packs is warmer because it is close to the warm ground. The ground is warm since the heat stored in the ground over the summer is slow to leave the ground because snow is a good insulator.”
Snow changes sounds we hear. “When the ground has a thick layer of fresh, fluffy snow, sound waves are readily absorbed at the surface of the snow. However, the snow surface can become smooth and hard as it ages or if there have been strong winds. Then the snow surface will actually help reflect sound waves. Sounds may seem clearer and travel farther under these circumstances.”
Snow crunches most in colder temperatures. “A layer of snow is made up of ice grains with air in between the ice grains. Because the snow layer is mostly empty air space, when you step on a layer of snow you compress that layer a little or a lot, depending on how old the snow is. As the snow compresses, the ice grains rub against each other. This creates friction or resistance; the colder the temperature, the greater the friction between the grains of ice. The sudden squashing of the snow at lower temperatures produces the familiar creaking or crunching sound. At warmer temperatures, closer to melting, this friction is reduced to the point where the sliding of the grains against each other produces little or no noise.”
Information and quotes are from the NSDIC website: http://nsidc.org/snow/faq.html

Della Moen, Earth Team Volunteer, NRCS/Stephenson Soil and Water Conservation District, an equal opportunity provider and employer, 01/06/10 for publication on 01/09/10 in the Journal Standard, Freeport, Illinois) Della can be reached at info@stephensonswcd.org