Relative humidity decreases when air temperature is lowered, without adding moisture, true or false?

Relative humidity decreases when air temperature is lowered, without adding moisture, true or false?

• A. True
• B. False
• C. Sometimes
• D. Depends on the situation

Answer: (B)

When air temperature is lowered without adding moisture, the capacity of the air to hold water vapor decreases. This happens because cooler air has a lower saturation vapor pressure, meaning it can hold less moisture compared to warmer air. As the temperature drops, the relative humidity can change depending on the actual amount of moisture present in the air. If no moisture is added as the temperature decreases, the relative humidity drops because the air is now farther from saturation at the new, lower temperature. Therefore, the statement that relative humidity decreases under these conditions is true, indicating the correct response is to affirm this concept.

When air temperature is lowered without adding moisture, the capacity of the air to hold water vapor decreases. This happens because cooler air has a lower saturation vapor pressure, meaning it can hold less moisture compared to warmer air. As the temperature drops, the relative humidity can change depending on the actual amount of moisture present in the air. If no moisture is added as the temperature decreases, the relative humidity drops because the air is now farther from saturation at the new, lower temperature. Therefore, the statement that relative humidity decreases under these conditions is true, indicating the correct response is to affirm this concept.