What is albedo and give examples of high- and low-albedo surfaces?

• A. Albedo is the reflectivity of a surface; high albedo examples: forests, oceans, asphalt
• B. Albedo is the reflectivity of a surface; high albedo examples: snow, ice, light clouds; low: forests, oceans, asphalt
• C. Albedo is heat absorption; high: asphalt; low: snow and ice
• D. Albedo is wind speed; high: open plains; low: forests

Answer: (B)

Albedo is the reflectivity of a surface to incoming solar radiation. It shows how much sunlight is bounced back into space versus how much is absorbed.

High albedo surfaces, like snow and ice, reflect a large portion of sunlight because their bright, clean surfaces scatter light effectively. Light clouds also reflect a lot of sunlight, making them high in albedo. These reflectivity properties help keep those surfaces cooler because less solar energy is absorbed.

Low albedo surfaces absorb most of the sunlight. Dark vegetation like forests, open water such as oceans, and dark pavement like asphalt soak up more energy, warming the surface.

This concept matters for climate: higher albedo tends to cool the surface by reflecting heat, while lower albedo leads to more heat absorption and warming. Albedo can vary with conditions—snow can darken as it melts or gets dirty, reducing its reflectivity.