The maximum amount of water vapor that can be in the air depends on the air temperature. The amount of water vapor in the air as compared with the amount of water that the air could hold is called relative humidity. This amount of space in air that can hold water changes depending on the temperature and pressure.

Additionally, what are the two major factors that account for the amount of water vapor in the atmosphere? There are limits to the amount of water vapor that can be held by any parcel of air. A very important determinant of the amount of water vapor that can be held by the air is temperature. The warmer air is, the greater the quantity of water vapor it can hold.

Similarly, how do you calculate water vapor capacity?

Using the curve above, at 28oC the water vapor capacity of the air is about 25 g/kg (25 grams of water vapor per kilogram of air). So, the relative humidity = 20/25=0.80 or 80%. Use the saturation curve above and the ones in Figures 6-7 and 6-8 to calculate relative humidity.

How does the capacity of air hold water vapor change with temperature?

The higher the temperature, the more water vapor a volume of air is capable of holding. Therefore, any change in temperature alters the volumes water vapor capacity. As air warms, its capacity for holding water vapor increases; as it cools, the capacity decreases.