What Is Albedo?
Albedo can be defined as a way of quantifying how much radiation is reflected from the surface. It is a comparison between the reflection radiation from the surface to the amount of radiation that hits it. This term also refers to the quantity of radiation generated by electromagnetic rays which consequently reflects away.
Seasonal Effects On Albedo
To understand albedo better, we look at two scenarios. One, if you walk barefoot on the black soil during summer, you will feel a lot of heat and can even get burnt because the surface is absorbing and retaining more heat. Another person walking on white soil during the same season will not be burnt. This is basically because white surface tends to reflect more heat and absorb very little of it. Equally, if you touch a black car in summer it will feel much hotter than touching a white car. This is because black absorbs and retains heat while white car surface will reflect back the solar rays.
During this season, it is generally wet with either water or ice. Water reflects approximately 6% of the light and absorbs the rest. Ice, on the other hand, reflects 50% to 60% of the incoming solar heat, thereby remaining cooler. A snow-covered area reflects a lot of radiation, which is why skiers having a risk of getting sunburns while on the slopes. Albedo diminishes when the snow-covered places start to warm up.
How Is Albedo Quantified?
Albedo helps us to know how well a surface reflects solar energy. It is measured on a scale of zero to one (0-1). Surfaces differ in absorbent ability but will always be in the range of between 0-1.
Value “0” - If a score of zero is given, then the conclusion is that the surface is highly receptive to light, meaning that the surface takes in all the light that comes into contact with it. It is characterized by black surfaces.
Value “1” - This score is evidence that the surface does not absorb incoming light. It is characterized by white surfaces.
The albedo of our planet is 0.367, whereas that of the moon stands at 0.12, meaning the moon reflects 12% out of the radiation that falls on it. There are many satellites set up to monitor the planet's albedo by use of sensors which measure the light from the Earth that reflects on the surface of the moon. NASA has set out what is called Terra and Aqua Satellites to assist identify any changes in albedo.