Soaking Up the Sun
The Poles are cold and the Tropics are warm because of the curvature of the Earth.
Scenario A
The sunlight at the Poles is less intense for several reasons:
- The sun’s rays strike the Earth at a slanted angle and spread out over of a large area.
- The arriving radiation from the sun are less intense at the Poles due to a smaller arriving angle of the sun's rays.
Scenario B
The sunlight at the Equator is more intense for several reasons:
- The sun’s rays strike the Earth at a 90 degree angle and in a straight line.
- The intensity of the sun’s rays is focused on a smaller area.