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One Hot Mother
Satellite image of Earth shows hot spots.Mother Earth would be as hot as the sun if she weren’t budgeting her pocketbook of radiation. The radiation budget is the balance between incoming and outgoing energy on Earth; it controls the temperature and climate.

Earth absorbs solar energy, heating us up just enough to live, or sweat buckets in a Midwestern heat wave. When the Earth’s atmosphere and surface heat up they emit thermal longwave radiation. Some of this radiation blows into space and allows Earth to cool.

This image of Earth was taken by Clouds and theEarth's Radiant Energy System (CERES) on the Terra Spacecraft, one of the planned constellation of satellites that will make up NASA’s Earth Observing System. It shows longwave radiation (heat), emanating from the top of Earth’s atmosphere. The thermal radiation leaving the oceans is fairly even and cool. The American Southwest (upper right hand corner) has little cloud cover, and thus is very hot with more thermal radiation to blow into space. In the tropics, less cloud cover from the 1980s to the 1990s allowed more sunlight, solar radiation, in and let more thermal radiation out. This change may have big implications for climate change and global warming.

Image courtesy Barbara Summey, NASA Goddard Visualization Analysis Lab, based upon data processed by Takmeng Wong, CERES Science Team, NASA Langley Research Center.

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