Ask Brandon: Why is Snow White While Rain is Not?

Brandon,

Why is snow WHITE when rain is not?

– Jeff Johnson, Sioux Falls

Dear Jeff,

The electromagnetic spectrum is the range of all possible frequencies of electromagnetic radiation. Inside of this spectrum we have many different frequencies: Microwaves, X-Rays, TV/Radio Waves, Ultraviolet (UV) Radiation and visible radiation. Visible radiation is visible light and is made up of a full spectrum of wavelengths that we can see. Within that spectrum of wavelengths, our brains detect different wavelengths to see colors. The smaller the wave, the colder the color (blue, purple, etc.), the longer the wave, the warmer the color (red, orange, etc.

When all of these wavelengths are blended together we get “white light” or the color white. Sunlight consists of all the colors that our eyes can see blended together into pure white light. When this light is shined onto an object (lets us the example of a car), that car will absorb some of the light and reflect some of the light. It’s the wavelength of the reflected light, the light that reaches our eyes, that gives the material its color. If light passes straight through an object, that object is known as transparent, also known as clear. This is why rain (and water) appear to be clear.

Snow on the other hand is not clear. It is made of very tiny ice particles which are translucent, meaning light doesn’t pass right through the material/object in a direct path. Because of these crystals, nearly all of the light that hits snow is reflected back. The little sunlight that is absorbed by snow is absorbed uniformly over the entire visible spectrum, thus giving snow its white appearance.

Do you have a question about the weather? Make sure to send it to Brandon at weather@kdlt.com or on Facebook or Twitter!