Despite the meager amount of new snowfall for most of Minnesota recently, have you noticed there is a crunch when you walk on even the thinnest coating of the powdery snow?
The physical composition of fallen snow crystals, as frozen water droplets, layered upon each other, create tiny air pockets. When your foot pushes the snow to the pavement it induces a small rush of heat as the particles compress. Research has shown that the physical properties are altered when the air temperature is cooler than about 15 degrees Fahrenheit. Thus during the recent cold snap, there is no melting under foot, there is a crunching sound. Ah, the sites and sounds of winter!
The story fits well with the favorite Christmas lyrics, hear the snow crunch, see the kids bunch…!