What Is the Science Behind Snow? Are There Different Kinds of Snow?
Snow…it’s something that we typically take for granted. It’s really just frozen rain, isn’t it? Then why doesn’t it come down on us like pellets of ice? Let’s take a closer look at the science behind the fluffy white stuff.
What Causes a Snowflake to Form?
The common assumption that snow is essentially frozen precipitation is correct, but a bit oversimplistic. Snowflakes do begin as tiny drops of water falling from clouds. The water is extremely cold, but not frozen (if it’s frozen, the precipitation is typically referred to as sleet or hail). As the drop of water descends, it attaches to a dust or pollen particle and freezes, creating the core crystal of a snowflake. As the crystal continues to make its way to the ground, it collects water vapors in the air, turning those vapors into new crystals. In almost every instance, by the time the snowflake is fully formed, it will have six crystal arms protruding from the center.
Are There Different Types of Snowflakes?
Yes. Scientists generally agree that there are varying types of snowflakes but cannot agree on what distinguishes them and how many types there actually are. The International Commission on Snow and Ice uses a classification system that includes seven types of crystals, but some scientists contend that there may be as many as 35 different types. All scientists agree, though, that no two snowflakes are the same.
What Determines the Shape of a Snowflake?
According to experts, it’s the temperature at which the water drop freezes…when the crystal is formed…that causes its basic shape. The warmer the temperature, the longer the crystals tend to be. Because the crystal typically goes through different temperature zones as it falls, it can take on a virtually endless array of crystal shapes.
Why Is Some Snow Heavy and Other Snow Feathery?
The weight of a snowflake depends almost entirely on its relative water content. In colder temperatures, the crystal does not gather as much moisture as it falls. When its very cold outside, the snow tends to be fluffy, but when the temperature is just below freezing, it will have a high liquid content and be much heavier.
