What term describes the transition zone between the troposphere and stratosphere?

The transition zone between the troposphere and stratosphere is known as the tropopause. This boundary acts as a lid that separates the two atmospheric layers and is characterized by a change in temperature gradient. In the troposphere, which is the lowest layer of the atmosphere, temperature generally decreases with increasing altitude. However, at the tropopause, the temperature stabilizes and then begins to increase in the stratosphere, where the ozone layer resides. This temperature inversion is critical because it acts as a barrier to vertical mixing of air, influencing weather patterns and the development of clouds.

In contrast, other terms such as thermosphere, stratosphere, and mesopause refer to different layers or transitional zones within the atmosphere. The thermosphere is located much higher and is characterized by increasing temperatures with altitude. The stratosphere is the layer above the tropopause but does not describe the transition itself. The mesopause is the upper boundary of the mesosphere, lying above the stratosphere, and is not relevant to the transition between the troposphere and stratosphere. Thus, the tropopause is the correct term that precisely identifies that transition zone.