Week of November 13, 2022 – November 19, 2022
by Elizabeth Suzedell, Environmental Educator
We have already had our first frost in Central New York, and waking up to a thin glaze of ice crystals covering the grass, other plants, and our cars is becoming more common as we approach mid-November. You may have occasionally noticed some thick dew throughout the autumn, and even though frost is ice, both dew and frost form in a very similar way.
Dew is the liquid water droplets that you see covering the grass or your car, usually on clear and still mornings. Overnight, the air temperature cools off since the sun is no longer heating the earth. If the temperature cools to the dew point, dew will start to form on the surfaces outside.
The dew point is the temperature at which the air needs to be cooled for water to start to condense into a liquid from a gas. When the temperature equals the dew point, the air is completely saturated with water- kind of like a full sponge. The air can no longer hold any more water vapor at this temperature.
Now that the mornings are getting colder to below freezing, we are getting ice or frost instead of dew. When the temperature cools down to the dew point (or frost point now that it is below freezing), water vapor in the air will turn into ice through deposition. This is the name of the process for when a gas turns into a solid.
Watch out for this delicate, crystal shaped, and beautiful surprise in the coming weeks!