Commercial Pilot Licence Aeroplane Meteorology Practice Test – Your Comprehensive Guide to Exam Success! 2026

As altitude increases in the atmosphere, the amount of moisture typically decreases. This is primarily due to the cooling of air as elevation rises. Cooler air holds less moisture than warmer air, leading to a decrease in humidity.

At higher altitudes, the atmospheric pressure is lower, causing the air to expand and cool. As the air temperature decreases, its capacity to retain water vapor diminishes, leading to reduced moisture levels. This phenomenon is particularly noticeable in the troposphere, where most weather occurs and the temperature gradient is significant.

In summary, the correct choice is that moisture in the atmosphere generally decreases with an increase in altitude due to the cooling effect that limits the air's ability to hold water vapor.