Final answer:
The tropopause altitude is highest at the equator due to intense heating from the surface caused by the direct angle and higher elevation of the sun's rays in this region.
Step-by-step explanation:
The tropopause altitude is highest at the equator because of the intense heating from the surface. The reason for this is that at the equator, the Sun's rays hit the Earth more directly and with a higher angle, causing greater heating of the surface compared to other parts of the planet.
This heating causes the air to expand and rise, pushing the tropopause to a higher altitude. The tropopause is the boundary between the troposphere and the stratosphere and represents the point in the atmosphere where the temperature stops decreasing with altitude and may begin to increase.
In contrast, the tropopause is lower at the poles where the solar radiation is more diffuse, and the angle of the Sun's rays is lower. The difference in the elevation of the sun, as well as the angle of its rays during different seasons, contributes significantly to the warming effect and thus the variability in the altitude of the tropopause.