Definition: Albedo is the amount of reflectivity of an object. The amount of incoming electromagnetic radiation is compared to the amount of radiation reflected by the object. Snow and ice have a high albedo while darker objects have a low albedo. For instance, imagine going outside on a hot summer day in a black shirt versus a white shirt. The white shirt has a higher reflectivity (higher albedo) and will therefore reflect some of the solar heat from the day.
In meteorology, cloud albedo is used to describe the manner in which sunlight either cools or warms the surface of Earth. High clouds will allow sunlight to get through and warm land surfaces. Low clouds will usually reflect sunlight. As an example, dense smoke and ash from a volcano will sometimes cool land surfaces. Overall, cloud albedo plays a role in climate moderation on Earth creating a radiation budget which keeps the net cooling and warming of Earth relatively even.
Resources:
- NASA video segment on albedo showing how polar ice reflects light from the sun
- An experiment on the albedo of different objects from the National Weather Service
Also Known As: reflectivity