Average Clear-sky Outgoing Shortwave Flux (WMS)

The Earth's climate is determined by energy transfer from the sun to the Earth's land, oceans, and atmosphere. As the Earth rotates, the sun lights up only part of the Earth at a time, and some of that incoming solar energy is reflected and some is absorbed, depending on type of area it lights. The average amount of reflection and absorption is critical to the climate, because the absorbed energy heats up the Earth until it is radiated away as thermal radiation. This animation shows the monthly average clear-sky outgoing shortwave radiation from July, 2002 through June, 2004 as measured by the CERES instrument. This is the sunlight that is directly reflected back into space by ice, desert, and other physical areas on the Earth when the sky is cloud-free. The ice sheets can be clearly seen to reflect the most sunlight, with desert areas next. Oceans absorb the most sunlight, more than the vegetated land areas such as the tropical rain forest and temperate forests and plains.

See http://asd-www.larc.nasa.gov/ceres/ASDceres.html