Question

Why is the height of tropopause over the equator more than that over the poles?

Answer 1

The height of the tropopause over the equator is more than that over the poles because of the difference in temperature and air density between these regions:

• At the equator, the surface air is much warmer. Warm air expands and becomes lighter, which causes the troposphere to extend up to about 18 km.
• Over the poles, the air is much colder and denser. Cold air is heavier and more compact, so the troposphere extends only up to about 8 km there.
• This variation in temperature leads to the variation in the height of the tropopause, which is the boundary at which the temperature stops falling with height.
• Additionally, the equatorial region receives more direct solar radiation throughout the year, warming the air more and causing it to rise higher.
• In contrast, the cold polar air sinks and remains lower in altitude, limiting the height of the troposphere there.

Thus, the tropopause is higher over the equator primarily because warm air expands the troposphere upwards, whereas over the poles, cold, dense air keeps it lower. The typical heights are about 18 km at the equator and about 8 km at the poles.