Because water vapor also condenses to make clouds, an increase in water vapor in the atmosphere also may increase the amount of clouds. Water vapor acts like a greenhouse gas, absorbing outgoing longwave energy. Water vapor in the atmosphere also affects our daily weather and climate, though scientists are only beginning to understand how this complex mechanism works. These changes can affect weather patterns around the world. Clouds appear over the relatively warmer portions of the eastern Pacific and decrease over the relatively cooler western Pacific. El Niño events occur when portions of the Pacific Ocean become considerably warmer than normal. For example, over the equatorial Pacific Ocean during El Niño events, there is a significant decrease in the amount of energy emitted by the Earth due to increased cloudiness. These differences affect the way clouds reflect sunlight back into space and how much longwave energy emitted by the Earth is absorbed by clouds and re-emitted. To date, satellite studies have found that clouds have an overall net cooling effect on the Earth.Īnalysis of satellite data also has shown that clouds which form over water are very different from clouds which form over land. Thin, high clouds, however, primarily trap outgoing longwave energy and produce warming. For example, low, thick clouds primarily reflect incoming solar energy back to space causing cooling. Understanding cloud effects requires a detailed knowledge of how clouds absorb and reflect incoming shortwave solar energy, as well as how they absorb and reemit outgoing longwave energy. Global Change Research Program classifies understanding the role of clouds and the Earth’s energy budget as its highest scientific priority. One of the most intriguing questions facing climate modelers today is how clouds affect the Earth’s climate and vice versa.
Major sources of aerosols include windblown dust, emissions from the burning of fossil fuels such as gasoline, and the burning of forests and agricultural fields biomass burning).
Some of the shortwave radiation from the Sun is also reflected back into space by clouds and small particles in the atmosphere called aerosols. Such changes may, in turn, cause changes in the Earth’s weather and climate. Increases in the amounts of greenhouse gasses (gasses in the atmosphere that absorb the long wavelength energy emitted by the Earth) can lead to a warming of the Earth’s surface. Scientists have been working for decades to understand this critical energy balance - to understand the budget of incoming and outgoing energy, called the Earth’s radiation budget.Ī major portion of the energy received from the Sun is at short wavelengths while the majority of energy emitted by the surface of the Earth and by clouds is at long wavelengths.
The Earth’s daily weather and climate are controlled by the balance between the amount of solar energy received by the Earth (both by its surface, and its atmosphere and clouds) and the amount of energy emitted by the Earth into space. However, it only operated during January - August of 1998, and March 2000, so the available data record is quite brief. The data from the CERES instrument was used to study the energy exchanged between the Sun the Earth’s atmosphere, surface and clouds and space. The Clouds and the Earth’s Radiant Energy System (CERES) instrument is one of five instruments that is being flown aboard the Tropical Rainfall Measuring Mission (TRMM) observatory.
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