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Meteorology
The heat released is the same amount of heat required to turn an equivalent
amount of water in a pot into invisible water vapor.
If you've tried to boil water away, you know that your electricity bill will
skyrocket if you want to boil all the water away.
Even more disturbing is that the water has just changed to invisible water
vapor.
Definition: Humidity is the amount of invisible water vapor in the air.
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3.5.3 Vapor pressure and saturation pressure
The atmosphere contains many different gases, each contributing to the total
air pressure. The portion of the pressure due to water vapor is called the vapor
pressure.
There is a maximum limit to how much invisible water vapor 1 m³ of air can
contain. This amount depends on the air's temperature. The warmer the air,
the more water vapor it can hold. When the air cannot hold more invisible
water vapor, it is said that the saturation pressure has been reached.
In meteorology, two types of humidity are used:
3
Absolute humidity: the number of grams of water 1 m of air
can contain at different temperatures.
Relative humidity: a percentage of the amount of water vapor
present in relation to the maximum
capacity of the air.
Flight Theory PPL(A)(UL)/LAPL Henning Andersen, Midtjysk Flyveskole© 2025 268
