: Reflectance under completely diffuse (cloudy) light.
Understanding Albedo: The Earth's Reflective Shield is a measure of the diffuse reflectivity of a surface, specifically indicating the fraction of incident solar radiation that is reflected back into space. It is a dimensionless quantity expressed on a scale from 0 to 1 (or 0% to 100%):
: The "true" albedo under real atmospheric conditions, calculated as a weighted average of the two. Real-World Examples of Surface Albedo Albedo
On a global scale, Earth's average albedo is approximately , meaning roughly one-third of the sunlight reaching our planet is reflected away. Types of Albedo
: A perfect reflector that bounces back all radiation. : Reflectance under completely diffuse (cloudy) light
: The brightness of a surface when viewed from the same direction as the light source, compared to an idealised reflecting disk. Blue-sky vs. White-sky vs. Black-sky : Black-sky : Reflectance under perfectly direct sunlight.
In scientific fields like astronomy and climatology, researchers distinguish between different ways of measuring reflectivity: Real-World Examples of Surface Albedo On a global
: A "black body" that absorbs all incoming radiation.
: The total fraction of incident electromagnetic energy scattered back into space by a planet or moon across all wavelengths and angles.