What is happening at certain elevations where the direction of temperature change reverses from decreasing to increasing or vice versa?

Question

Quizplus · Accepted Answer

These elevations delineate boundaries that separate the distinct layers of Earth's atmosphere. These layers are defined by changes in temperature and composition, and the direction of temperature change alternates between increasing and decreasing at these boundaries. For example, the boundary between the troposphere and the stratosphere is known as the tropopause, where temperature stops decreasing with altitude and begins to increase.

What Is Happening at Certain Elevations Where the Direction of Temperature