The ratio of the amount of water vapor actually in the air compared to the amount of water vapor the air can hold at the particular temperature and pressure. The ratio of the air's actual vapor pressure to its saturation vapor pressure.
WRCC Climate and Weather Terms Glossary The ratio of the amount of water vapor in the air compared to the amount required for saturation (at a particular temperature and pressure).
NASA Earth Observatory
Relative Humidity - This is the ratio between the actual water vapor content of the atmosphere and the maximum water vapor content possible at that given temperature. If the temperature of a given parcel of air rises, the amount of moisture it can hold increases and as such its relative humidity decreases. If there is no change in temperature but the moisture content decreases then the relative humidity will again decrease because the ratio of actual water vapor present is less than the maximum amount the air could hold. Conversely, if the water content does not change but the temperature falls, the relative humidity increases until saturation and possible precipitation occurs.
[Ocean; v17; p34-6; 1984.] [Science News; v132; p236; 1987.]
Atmospheric Chemistry Glossary |
