The Atmospheric System and Energy Balance

Earth's climate is ultimately powered by the Sun. Almost all of the energy that drives the atmosphere, oceans, and weather arrives as shortwave radiation, most of it concentrated in visible and near-infrared wavelengths because the Sun is extremely hot. When this radiation reaches the top of the atmosphere, it does not all stay in the system. Some is reflected straight back to space by clouds, airborne particles, and bright surfaces; some is absorbed by gases and dust as it passes through the atmosphere; and the remainder is absorbed at the surface, warming land and oceans. Understanding where this incoming energy goes, and how energy leaves again, is the foundation for understanding climate and climate change.

The fraction of incoming solar radiation that a surface reflects is called its