What Causes Snow – During the wintertime, you notice something white that falls on the ground. This phenomenon is called snow. Snow usually shows itself during this season, but what exactly causes it?
With science, we will give you a full explanation of what causes snow including the different snow, snowfall, and snow formations!
What Causes Snow?
Let us begin by telling you what causes snow. In short, snow is created when warm air combines with a low-pressure area, also called an extratropical cyclone.
To give you a more in-depth description of the cause of this phenomenon, the air is lifted along with water vapor. Water vapor is created from air mass which helps create the clouds in the sky.
Ice particles are at freezing temperatures (as low as -40 degrees)! and they will eventually turn into an ice particle. Once the ice particles join the clouds, they grow and combine together to become large.
So large, in fact, that their fall speed is higher than the speed of the air!
From there, snow will begin to fall from the sky. The reason why is because if the ice particles do not re-evaporate, they won’t be able to stay in the clouds.
The more water vapor that is provided for the clouds, the stronger the drafts become, making more snow.
So if you there is a cold day and there are gray clouds outside that don’t sprinkle snow, this means that there is not enough water vapor for the clouds or the motion of the clouds is slow, therefore the cloud is unable to create snow. In some occurrences, the reason why it doesn’t snow is from both of the explanations mentioned.
So there is an explanation of what causes snow! But what about snow in the mountains? In the mountains, the air is forced to rise over the mountain where large snowfall will occur.
This is known as orographic precipitation, where the downwind side of the mountain receives little to no snow since the water vapor leans more towards the upwind side of the mountain.
Now that you know what causes this wintry phenomenon, let us go over the types of snow!
Types Of Snow
There are four different types of snow. These include the following:
- Snowflakes: These are singular ice crystals or clusters that form in the sky that will eventually fall from the clouds.
- Hoarfrost: A deposition that occurs when the temperature of the surface is lower than the frost point of the surrounding area. During this process, moisture automatically turns into a solid (ice crystals). You can find hoarfrost on objects like wires, poles, tree branches, plant stems, and leaf edges.
- Graupel: Graupel are snowflakes that are round in shape and opaque. Their dimensions are about two to five in diameter and are formed from supercooled droplets.
- Polycrystals: These are snowflakes that are comprised of many individual ice crystals.
Types Of Snowfall
As for snowfalls, there are seven different types of snowfall:
- Blizzard: The most chaotic out of the seven, blizzards are created when subfreezing temperatures and wind meet to create a strong snowstorm.
- Snowstorm: This type of snowfall is where copious amounts of snowfall from the sky.
- Snow Flurry: This type of snowfall is a lighter, shorter duration that comes with different intensity. This form produces less snow.
- Snow Squall: Like a snow flurry, snow squall is brief. However, snow squall increases the snowfall which makes it difficult to see.
- Snowburst: This type of snowfall is an intense form of a snowshower, but it will only last for a short time. This form increases snow accumulation.
- Blowing Snow: This is a term used when airborne snow particles are raised into the sky where they will go high to the point that you won’t be able to see them at a horizontal level.
- Drifting Snow: The last one on snowfall, this is where snow is blown on the ground due to the wind. Snow reaches about 1.5 to 2 meters above the surface.
Types Of Snow Formation
There are ten snow formations in total that happen in the world
- Cornice: This is an accumulation of ice and snow that was blown from the wind to create an overhanging formation. You find this form on the edge of a ridge or cliff face.
- Crust: Crust is described as being a hard snow surface that settles on a soft surface. Crusts can be formed from three different sources: sun, rain, and wind.
- Megadunes: Found in Antarctica, these are enormous dunes that are comprised of large ice crystals that measure two centimeters across.
- Penitents: These are pinnacles that are described as being thin, tall, and are closely spaced. Penitents usually happen in mountainous areas like the Dry Andes or the Death Valley.
- Ripple Marks: This form of snow formation happens when the snow surface is affected by the wind.
- Sastrugi: This occurs when the wind carries snow in places where snow typically isn’t found. You can find this in grooves or ridges.
- Snow Barchan: A formation of snow that is in the shape of a horseshoe that is pointed downward.
- Snow Bridge: This is where an arch is created from the snow that is drifted across in a crevice.
- Snow Roller: The rarest one out of all of the snow formations, snow rollers happens when there are certain specific meteorological conditions. Snow rollers are cylindrical in shape rather than circular shaped.
- Sun Cups: The last snow formation is sun cups. Sun cups are formed when there is intense sunshine. They are described as being shallow and are usually in the shape of a bowl.
Effect Of Snowfall On The Ecosystem
Snow, like the other precipitation of weather, is important for the environment. When it melts, the snow turns into the water which will then go into bodies of water. This is then used for irrigation and basic consumption.
Snow also acts like a warm blanket for the earth as snow doesn’t have much heat. Because of the warm blanket, it makes it easier for plants and animals to adapt to a cold environment.
This is the full explanation of what causes snow. If you want more information, you can find different science experiments that you can do at home to learn more about snow!
Written by Alicia Bartona