Variation of radiation with latitude

• Due to the curvature of the earth, in the tropics the suns rays are concentrated on a much smaller area, resulting in more intense heat
• Rays have less atmosphere to pass through at the tropics, so less energy is lost through absorbtion and reflection
• Albedo is the reflectivess of the land surface. Darker forest surfaces at the tropics have a lower albedo so absorb more energy. In contrast with the lighter snow and ice covered areas at the poles
• Due to the tilt of the earth, limited insolation is recieved at the poles in winter, where as tropical areas recieve insolation all year round