The height of the tropopause increases near the equator. What does this say about the thickness of the atmosphere?
The increase in height of the tropopause near the equator indicates that the thickness of the atmosphere also changes. To understand this relationship, it's essential to review the concept of the tropopause and its height variation.
The tropopause is the boundary between the troposphere (the lowest layer of the Earth's atmosphere) and the stratosphere (the layer above the troposphere). It is a transition zone where temperature generally stops decreasing vertically with increasing altitude and remains fairly constant or may even increase within the stratosphere.
Near the equator, there are specific atmospheric circulations known as Hadley cells that play a significant role in the height variation of the tropopause. These atmospheric cells are responsible for the redistribution of heat from the equator to higher latitudes.
Within the Hadley cells, warm air rises near the equator due to heating from the sun. As the air rises, it cools and expands, causing the tropopause to be higher in altitude. This ascent of warm air creates a thicker troposphere near the equator.
Conversely, at higher latitudes, colder air descends and warms as it moves towards the poles. This sinking motion compresses the atmosphere, leading to a lower tropopause altitude and a thinner troposphere.
Therefore, the increase in height of the tropopause near the equator suggests that the atmosphere is thicker at that region compared to higher latitudes.