The dew point is the temperature at which moist air becomes saturated with water
ID: 3280966 • Letter: T
Question
The dew point is the temperature at which moist air becomes saturated with water vapor. We can therefore represent how moist a particular parcel of air is by comparing its actual temperature with its dew point temperature.
We see the practical effect of reaching the dew point when on a cold day, we "see our breath" when we exhale.
Suppose it is -10 degrees Celsius outside and our breath leaves our body at 30 degrees Celsius, whereupon it mixes with the outside cold air in a one to one ratio (equal parts warm breath and cold air).
If your breath has sufficient moisture to have a dew point of 24 °C and the outside air has a dew point of -14 °C, will we be able to see our breath after it mixes with the cold outside air?
Show all your work, thank you.
Explanation / Answer
Yes we will be able to see our breath until it mixes with the air outside. As being outside, it will try to attain a temperature which is equal to that of air present outside. After mixing, as the dewpoint of outside air is -14oC which is lesser than the outside temperature, hence dewpoint will not be attained. Which means the air from our breath would not saturate.