With air temperatures this morning well below zero in northern Minnesota (minus 29 in Cook, minus 42 windchill in International Falls, and minus 22 at our house), I thought this would be a good time to post this video I made of Instant Water Vaporization a few years ago at my house on a minus 20 morning. “Poof, There it Goes,” (sung to Tag Team’s Whoomp—There it is) would be an appropriate anthem for this weather/water phenomenon.
HOW TO DO IT YOURSELF
1. Wait until the ambient air temperature is Minus 20 F or colder.
2. Boil water on the stove and pour it in an insulated coffee mug. (Put in a thermos if you need to travel to a site)
3. Run outside and pour some into a smaller cup (1/2 cup or 1 cup measuring cup works great)
4. Launch the water into the air (up, but not over your head!…There will still be some droplets coming down)
5. Watch in awe.
EXPLANATION OF THE PHENOMENON (from http://www.waterencyclopedia.com)
“A cup of boiling hot water thrown into very cold air (for example, at −37°C, or −35°F, as shown in the photograph) will almost instantly freeze in midair and create a shower of tiny ice crystals. There are several reasons behind this phenomenon. First, the near-boiling water is already close to becoming steam when it is thrown into the air, which means that the water molecules are much closer to evaporating into the vapor state than they would be if the water were cold.
Second, the act of throwing the water into the air causes it to break up into tiny droplets. The water that was contained in the cup (which originally had a relatively small surface exposed to the air) now experiences a tremendous increase in the total surface area exposed to the air. This situation helps to speed up the evaporation process (evaporation is the process of turning from a liquid to a vapor).
Finally, very cold air typically has a low humidity level (that is, a low amount of water vapor present). This is yet another factor aiding the transition from liquid water, to water vapor, to ice crystals. At sufficiently low temperatures, this process seems to occur almost instantaneously.”
Learn more fun water facts here