You may have notice when there is snow of the ground the days and night tend to be cooler. Snow is a great reflector of sunlight. The more sunlight that is reflected into the atmosphere the harder it is to warm.
Snow has a very high albedo, its ranges from 0.90-0.40. You may be thinking what is albedo? Albedo indicates how well a surface reflects solar energy. If a surface reflects all the solar energy back into the atmosphere, then it has an albedo of 1. If a surface absorbs all the solar energy that it has an albedo of 0. The whiter the surface the higher albedo, making the surface cooler. The darker the surface the lower the albedo, making it warmer.
Snow has a wide range in albedo. Fresh snow has an albedo of .90 while, melting snow is closer to .40. This means snow can reflect 40 to 90 percent of incoming solar energy back into the atmosphere. The less energy absorbed the harder it is to warm. The fact that snow reflects more energy than absorbs it makes us cooler.
The albedo of the Earth’s surfaces ranges from 0.1-0.2 for the darker rougher surfaces to 0.4-0.5 for lighter and smoother surfaces. This means the darker surfaces reflect only 10-20 perfect of energy and absorb the other 80-90 percent which makes them warmer. The lighter surfaces reflect 40-50 percent of the energy and only absorb 50-60 percent which makes them cooler.
The ocean has a very low albedo. Typically, the ocean surface has an albedo of .06. This means that the ocean absorbs 94 percent of the solar energy and reflect 6% back into the atmosphere.
This is why we are told not to wear dark colors during the summer months. The darker the color the more solar energy is absorbed, making you warmer. The lighter colors reflect more solar energy, keeping you cooler.
*Reminder: The closer a surface is to (1.0) the more energy it reflects, making them cooler. The closer it is to (0) the more energy is absorb making them warmer.
Here is a list of common surfaces and their albedo value:
- New asphalt, 0.04 – 0.05
- Aged asphalt, 0.1 – 0.12
- New concrete, 0.4 – 0.55
- Aged concrete, 0.2 – 0.3
- Black acrylic paint, 0.05
- White acrylic paint, 0.8
- Green grass, 0.25
- Bare soil, 0.17
- Conifer Forest, 0.08 – 0.15
- Desert sand, 0.4