albedó

Albedo refers to the measure of how much light that falls on a surface is reflected back. It is expressed as a fraction or percentage, ranging from 0 to 1 (or 0% to 100%). A surface with an albedo of 1 reflects all incident light, while a surface with an albedo of 0 absorbs all incident light. The term originates from the Latin word "albus," meaning white.

Different surfaces have different albedos. Fresh snow, for example, has a very high albedo, reflecting most of the sunlight. Dark surfaces like asphalt or a black t-shirt have a low albedo, absorbing a significant amount of sunlight and converting it into heat. Natural surfaces vary widely: forests typically have lower albedos than grasslands, and oceans have some of the lowest albedos due to water's absorptive properties.

Albedo plays a crucial role in Earth's energy balance. Surfaces with higher albedos reflect more solar radiation back into space, helping to cool the planet. Conversely, surfaces with lower albedos absorb more solar radiation, contributing to warming. Changes in albedo, such as deforestation or the melting of ice and snow, can therefore have significant impacts on local and global temperatures and climate patterns. The concept is also applied in astronomy to describe the reflectivity of celestial bodies like planets, moons, and asteroids.