Certified Transport Registered Nurse Certification Practice Exam

What happens to humidity as altitude increases?

1. Increases

2. Decreases

3. Stays the same

4. Fluctuates

The correct answer is: Decreases

As altitude increases, the air pressure decreases, which leads to a decrease in the amount of water vapor the air can hold. This is due to the fact that warmer air can hold more moisture than colder air. As elevation rises, temperatures generally drop, resulting in a decrease in the capacity of the air to retain humidity. Consequently, the overall humidity level decreases as altitude increases, making this choice the correct one. It's important to note that while humidity may fluctuate based on local weather patterns or other environmental factors at various altitudes, the general trend is a decrease in humidity due to the physical properties of air at higher elevations. Temperature, pressure, and the water vapor capacity are all critical elements that define humidity levels in the atmosphere at different altitudes.