Science Smarts: Clearing up the science of fog
By Patty Rooks on November 18, 2023.
When I woke up this morning, oh my was it foggy out! I could not see to the end of my driveway it was so thick. This is not surprising really as there was quite a snowfall and drop in temperature overnight. With that being said, it left behind a beautiful glistening frost on the trees – it almost looked magical in fact. All this talk about fog has me wondering how it all works. Let’s get started! * Remember to ask an adult before doing this experiment. Materials – Black paper – Wooden matches – Water – Food colour – Mixing spoon – Medium size GLASS jar – Tape – Scissors – Ice – Small zipper bag – Ruler – Pencil – Adult helper Procedure 1. Fill the small zipper bag about ½ full of ice. Set aside for now. 2. Pour enough WARM water into the jar so it is about 1/3 full of warm water. 3. Add a few drops of food colouring and mix well. 4. Cut a strip of black paper to go around the jar. You want the strip to be about 4cm wide and long enough to go around the entire jar. Measure and cut. 5. Tape the black paper on the jar JUST ABOVE the top of the water line in the jar. 6. Have the adult helper light the match and hold it over the opening of the jar. 7. Let it burn for about two seconds – BE CAREFUL. 8. Drop the match into the water and quickly cover the jar opening with the bag of ice. 9. Observe what is happening in the jar. 10. Repeat if necessary. What is going on? Can you see anything happening inside the jar? You should have seen a very small cloud or “fog” form. This cloud forms because the warm water heats the layer of air that it touches. Some of the water also evaporates into the air forming water vapor. The warm air containing water vapor rises and cools as it comes into contact with the air cooled by the ice. When the water molecules cool, they slow down and stick together readily. The particles of smoke you introduces with the match acted as a source for the water molecules to collect on forming the “fog.” Investigate further at home as there are many types of fog: advection fog, upslope fog, freezing fog, evaporation or mixing fog just to name a couple! Patty Rooks, Senior Scientific Consultant PRAXIS, “Connecting Science To The Community.” Contact Praxis at praxis@praxismh.ca, http://www.praxismh.ca, Tweet or follow us @PraxisMedHat, or friend us on Facebook. Address: 12 826 11th Street SE, Medicine Hat, AB, T1A 1T7 Phone: 403-527-5365, email: praxis@praxismh.ca. 33-32
