Final answer:
The addition or removal of heat to the air without a change in moisture content alters the air temperature. The process, excluding phase changes such as evaporation and condensation, involves a direct impact on temperature without the accompanying heat transfer that stabilizes the air temperature near the dew point in humid conditions.
Step-by-step explanation:
The addition or removal of heat to the air without any change in the moisture content results in changes in air temperature. In this process, since the moisture content remains constant, there is no phase change (such as evaporation or condensation) associated with it, which could transfer significant amounts of heat. Heat added to the air raises its temperature, while heat removal lowers the temperature, provided that the air's moisture content remains unchanged.
This principle underlies phenomena such as the cooling effect of evaporation experienced when sweat evaporates from the skin. It also explains why places with low humidity, like deserts, experience large temperature ranges - because there's less moisture, no heat is released through condensation, allowing temperature to drop more swiftly at night.
Dew Point and Temperature Stability
The dew point serves as an important marker for temperature change. When air temperatures near the dew point, further cooling leads to condensation, releasing heat and stabilizing the temperature. That is why in humid climates, temperatures do not usually fall below the dew point, as the heat released during condensation prevents further temperature decreases.