Which of the following best describes the standard lapse rate?

The standard lapse rate refers to the average rate at which temperature decreases as altitude increases in the Earth's atmosphere. As you ascend in altitude, particularly in the troposphere, the temperature typically drops at an approximate rate of 6.5 degrees Celsius per kilometer. This consistent decrease in temperature with increasing altitude is a key principle in atmospheric science, helping to explain phenomena such as weather patterns and flight performance.

The fact that the lapse rate is typically a constant decrease distinguishes it from other descriptions of temperature behavior with altitude. A constant increase, variable temperature, or fluctuating temperature do not accurately capture the prevailing trends observed in the lower atmosphere where this standard lapse rate is most applicable. Thus, the statement that the temperature decreases consistently with altitude is a core understanding of atmospheric behavior and essential for those studying aerospace physiology and meteorology.