Vail Daily column: What exactly is snow?
Vail, CO Colorado
“Oh! The snow, the beautiful snow,
Filling the sky and earth below,
Over the housetops, over the street,
Over the heads of the people you meet.
– J.W. Watson
Snow can inspire poetry and brighten the eyes of snow sport enthusiasts. But it can also wreak havoc on roads and dampen travelers’ spirits. It can be a burden or a delight. However, I am confident that whoever you choose to ask will agree that the beauty of snow falling from the sky is unparalleled in nature.
What is snow? Silly question, some might say, but over the past several years working with Walking Mountains, I have discovered the unique and complex world of snow. I cannot claim that I am an expert, but I consider myself more than a novice, and in this short article, I can only skim the surface of the intriguing world of snow. My goal is simply to extend my appreciation of the cold white stuff we see in the sky and on the ground for so many months out of the year here in the mountains.
One definition of snow is: precipitation in the form of small white ice crystals formed directly from the water vapor of the air at a temperature of less than 32 degrees Fahrenheit (0 degrees Celsius).
After studying and teaching snow science to a variety of age groups, it is far more complex than that. When you ask a third-grader what is snow, you get a variety of responses – “it’s cold and wet,” “it’s yucky,” “it tastes good,” “stay away from the yellow snow” and then occasionally you will get “it’s frozen water!” Depending on whose perspective, all of these answers are correct!
With younger students, at first it takes some serious enthusiasm on our part to get them excited to study snow, but once they begin to see how snow crystals form, how different snow can look and even how it continues to change when it hits the ground, it becomes more than just something fun to have a snowball fight in or use to build a snowman.
Snow forms when water vapor cools inside clouds. In simple terms, we give students three components that must be present for snow to form: one, a nucleating particle or, in third-grade language, a dust particle; two, water vapor; and, three, below-freezing temperatures. What is fascinating about snow is that temperature, air currents and humidity can influence the shape and size of the snow crystals that form, making it possible for the statement “no two snowflakes look the same” to be true.
There are many types of snow crystals, but for the purpose of working with young students we often focus on four broad categories: plates, needles, columns and dendrites. Most often, six-sided hexagonal crystals form in high clouds, needles or flat six-sided crystals form in middle height clouds and a wide array of six-sided crystals form in low clouds. Colder temperatures allow for more intricate snow crystals to form such as dendrites and sector plates, while warmer conditions allow snow crystals to grow more slowly, which causes shapes to be smoother and less intricate, such as columns, needles and thin plates. You can begin to understand just how complex snow is when you hear the many environmental factors that influence the snow falling through our sky, not to mention that once it hits the ground the snow metamorphoses even more causing potential instabilities in our snowpack.
One of our greatest teaching tools is to be able to take kids out of doors and have them make up close observations of the snow. I encourage anyone who recreates in the snow, admires the snow or even loathes the snow to take the time to learn more. In Eagle County, it is not only aesthetically appealing for some, but allows for our local economy to thrive and serves as the source of water for more than just the individuals living in this valley.
For additional resources, visit http://www.snowcrystals.com.
Gina Garrett is the youth programs director for Walking Mountains Science Center. When she’s not sharing the fascinating world of snow with students, observing snowflakes on the ski slopes keeps her smiling.