While radiation from the sun reaches every part of the Earth’s surface, the heating caused by solar radiation is uneven due to a variety of factors, including the shape and tilt of the Earth as well as the texture and color of the surface.
The texture and color of the Earth surface affect the albedo, how much solar radiation is reflected, which also influences how much radiant energy, or heat, is absorbed in a particular location. A surface with a high albedo reflects a lot of solar radiation, while a surface with low albedo reflects very little. Since the Earth’s surface is made of many colors and textures, it is heated unevenly. Snow, ice, and clouds reflect a lot of solar radiation back into space while green forests, vegetated lands, and exposed soil absorb solar radiation. You can experience the effect of albedo yourself with clothing on a sunny day. Would you feel cooler wearing a light- or dark-colored shirt on a hot, sunny day?
In this experiment, you will investigate the relationship between the albedo of different surfaces and the temperature change due to energy absorption. You will measure the amount of light reflected from paper of various colors using a light sensor and calculate percent reflectivity. You will also measure the temperature change of the air under the surface due to energy absorption using a temperature sensor.
- Use a light sensor to measure the amount of light reflected from different colored pieces of paper.
- Calculate the albedo of different surfaces.
- Use a temperature sensor to measure the amount of energy absorbed for each color of paper.