By Meghan Burton Period 3 June 12, 2006 Describe the greenhouse effect. Why is the equator hotter? Why do we have seasons? By Meghan Burton Period 3 June 12, 2006

How the Sun Hits the Earth… Poles EARTH Sun Equator Axis Poles

Why is the equator hotter, than the poles? The equator is hotter because the direct rays of the sun striking near the equator are more effective in heating an area than the slanting ray striking the polar regions, slanting rays spread their energy over a large areas that a direct ray.

Why do we have Seasons? Change in the angle at which the sun’s rays strikes the earth’s surface and changes in the amount of day of light which cause seasons Example: When the North Pole is tilted away from the sun, the angle of the sun’s rays is falling on the Northern Hemisphere is lower, the result is fewer hours of day light.

Continued… The weak rays of the sun and the short hours of day light produced the cool winter season in the Northern Hemisphere The angle at the sun’s rays striking the Southern Hemisphere is higher, and there are more hours of day light. The sun’s strong rays and the longer the hours of day light produce a warm summer season there.

Greenhouse Effect The process by which the atmosphere absorbs radiation which has been compared to a greenhouse The glass of a greenhouse allows the short wave lengths of visible light and infrared rays from the sun to pass through the interior Experiments shown that a greenhouse is also heated because air warmed by the infrared rays is prevented from escaping… this is the same way the atmosphere is heated. The process by which the atmosphere traps infrared rays over the earth’s surface is called the greenhouse effect.