- Emily Stoll
- Saturday, July 25, 2020
During this science experiment, WLTX Meteorologist Danielle Miller is focusing on dew point and frost.
Weather Lesson
Dew point is the temperature in which air needs to cool in order to reach saturation. So basically, as the temperature reaches its dew point, water droplets are going to begin to form - otherwise, known as dew.
Now, when this process happens below freezing, it's called the frost point instead of the dew point. Therefore, instead of getting tiny water droplets... you guessed it... you get frost.
It's pretty easy to create these conditions at home with this experiment.
Materials
- a tin can
- salt
- crushed ice
Instructions
- You'll want to take your crushed ice and put it into a tin can about half of the way full. Almost immediately, you'll start to see some water condensing on the sides.
- Next, sprinkle a good amount of salt to cover the ice and shake it all around the can. After a few minutes, you'll see frost form on the sides of the can.
- The longer you let it sit, the more frost you're going to see.
Evaluation
So, what exactly is happening? Well, the salt forces the freezing point of water to drop below 32*F. In this set-up, you cooled the can below freezing and had the air surrounding the can reach its frost point.
Danielle Miller is a meteorologist at WLTX-TV in Columbia, SC who provides regular weekend forecasts and digital content during the week. Learn more about Miller and how she got interested in weather by clicking here.