Private Pilot Private Exam

What happens to air temperature when it rises?

1. It decreases

2. It remains constant

3. It increases

4. It becomes unstable

The correct answer is: It decreases

When air rises in the atmosphere, it typically experiences a decrease in temperature. This phenomenon is largely due to the reduction in atmospheric pressure as altitude increases. As air rises, it expands because there is less pressure exerted on it. This expansion causes the air to cool. The rate of this cooling is generally known as the adiabatic lapse rate, which can average about 3.5 degrees Fahrenheit per 1,000 feet of ascent for unsaturated air. Understanding this cooling process is essential in aviation, as it affects weather patterns, cloud formation, and overall flight performance. Warmer air tends to rise, and when it encounters cooler temperatures at higher altitudes, it can lead to condensation and cloud development, which are crucial for pilots to understand for flight safety and weather assessment. The other options—stability of temperature or increase in temperature—do not accurately represent the standard behavior of rising air in the atmosphere under normal conditions, which consistently leads to a decrease in temperature.