What temperature drop is expected for every 1,000 feet increase in altitude from sea level under standard atmospheric conditions?

The correct answer reflects the standard lapse rate in the atmosphere, which is a key concept in understanding temperature changes with altitude. Under standard conditions, the atmosphere typically cools at a rate of approximately 2 degrees Celsius for every 1,000 feet of altitude gained. This is traced back to the ideal gas law and the physical properties of air as you ascend in the atmosphere where pressures are lower and the air expands, leading to decreased temperatures.

When flying or training, recognizing how temperature affects performance, equipment functionality, and weather patterns is crucial. The lapse rate assists pilots in making informed decisions regarding flight conditions and altitude changes.

In contrast, other options, such as a 1 degree C or a 3 degrees C drop, do not accurately reflect the standard atmosphere model. Similarly, the 4 degrees C figure is also higher than what is established by atmospheric science and could lead to misunderstandings about weather phenomena and flight planning. Understanding the correct lapse rate helps pilots anticipate how conditions may change with altitude.