Summary Use a flashlight on a large ball to show how the intensity of the sun varies between the equator and the more polar regions Science content Earth/Space: Weather, Seasons, Climate Change (K, 1, 4, 7) Earth/Space: Sun, Moon, Solar System, Universe (1, 4, 6) Lessons activity is in Weather - what causes it? Biomes Temperate rainforest ecosystem and the nitrogen cycle Materials large ball e.g. exercise ball flashlight with a beam that can focus to a circle darkened room chalk Procedure Explain that the ball is a model of the earth. Check that students know where the equator, poles, and their own city are. Turn the room lights off. Hold the flashlight level with the centre of the ball, from a couple of metres, so that a circle of light falls on the equator. Ask a student to draw around the circle. This models the sun's rays reaching the equator. Keep the flashlight at the same distance but move it up so that it now shines on a more northern region of the "earth". Ask a student to draw around the patch of light on the ball now - it should be an elipse. This is how the light falls on the more northern regions. Turn the room lights on and compare the outlines of the light patches. Discuss the intensity of light in each of the regions - it must be more intense at the equator as it covers a smaller area. Explain that in the same way, the equator of the earth receives much more intense sunlight than the more northern and southern latitudes. Relating to how weather starts, the tropics are warmed up more by the sun, and the warmer land and ocean there means the air above it is heated up more. The sun's angle on Earth helps determine why we get different biomes; Biome map: https://askabiologist.asu.edu/sites/default/files/resources/articles/bi… (from this article - https://askabiologist.asu.edu/explore/biomes) or https://cdn.britannica.com/38/102938-050-6B5388D9/distribution-biomes.j… for terrestrial (Earth, not water) biomes. Notes Tape a map of Earth Biomes onto the ball? Grades taught Gr 1 Gr 2 Gr 3 Gr 4 Gr 5 Gr 6 Gr 7
