How does specific humidity change with temperature and what must happen to the air temperature of unsaturated air in order for condensation to occur?
Specific humidity is a measure of the actual amount of water vapor present in the air, expressed as the mass of water vapor per unit mass of air. It is not directly affected by changes in temperature; instead, it is primarily influenced by changes in the amount of water vapor present in the air.
As temperature increases, the air's capacity to hold water vapor also increases. This means that at higher temperatures, the air can hold more water vapor without becoming saturated. However, if the actual amount of water vapor in the air remains constant while the temperature increases, the specific humidity will decrease because the relative amount of water vapor in the air compared to its capacity has decreased.
To summarize, specific humidity is not directly dependent on temperature changes; it is influenced by the absolute amount of water vapor in the air.
For condensation to occur in unsaturated air, its temperature must decrease. When air cools, its capacity to hold water vapor decreases, even if the actual amount of water vapor in the air remains the same. If the temperature drops low enough, the air may become saturated (reaches its dew point), at which point condensation begins. This is because the air can no longer hold all the water vapor it contains due to the reduced capacity at the lower temperature.
In other words, to trigger condensation in unsaturated air, the air temperature must decrease until it reaches the dew point temperature. This allows the air to become saturated, and any further cooling causes excess water vapor to condense into visible water droplets or other forms of moisture, such as fog or clouds.
- Badges
- Science topic
- Similar topics
- Geoscience
- Atmospheric Sciences
- Atmosphere
- Air