The measure of how much solar radiation is reflected by a surface is known as what?

• A. Albedo
• B. Absorption
• C. Scattering
• D. Infrared index

Answer: (A)

Albedo is the measure of how much solar radiation is reflected by a surface. It’s expressed as a fraction or percentage between 0 and 1, where high albedo means the surface reflects most of the sunlight (like fresh snow), and low albedo means it absorbs more energy (like dark asphalt). This concept is key in understanding how surfaces influence the Earth’s energy balance and climate. Absorption, on the other hand, is about how much energy the surface takes in, which is essentially the complement of reflectance. Scattering describes light being redirected in many directions and can affect brightness, but it’s not the overall reflectivity measure. The term infrared index isn’t a standard measure of reflectivity either. So, the quantity that directly quantifies the fraction of incoming solar radiation that is reflected is albedo.