What is the term for radiation that is reflected from Earth's surface?

• A. Albedo
• B. Absorption
• C. Transmittance
• D. Emissivity

Answer: (A)

When solar radiation reaches Earth's surface, some of it is reflected, some is absorbed, and some may be transmitted below the surface or into the atmosphere. The term for the fraction that is reflected is albedo. It’s a dimensionless measure of surface reflectivity, with higher values for bright surfaces like snow or ice and lower values for dark surfaces like oceans or forests. Emissivity describes how effectively a surface emits radiation, not how much it reflects. Absorption refers to energy taken in by the surface, and transmittance is about energy passing through a material. So the radiation reflected from Earth's surface is described by albedo.