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Science Priorities

CERES is focused on four important Earth Science Enterprise priorities for understanding the total Earth system and the effects of natural and human-induced changes on the global environment.

Long-Term Climate Variability

Radiation and clouds strongly influence our weather and climate. For example, low, thick clouds reflect incoming solar radiation back to space causing cooling. High clouds trap outgoing infrared radiation and produce greenhouse warming. The Earth Radiation Budget Experiment (ERBE), which was launched on multiple satellite in the mid 1980s, and now the EOS CERES instruments, are providing critical data on the effect of clouds on climate. The data indicate that clouds have an overall net cooling effect on the Earth (i.e., negative net cloud forcing in the figure below). The largest negative cloud forcing is found over the storm tracks at high-to-middle latitudes in the summer hemisphere. The most extreme values occur over marine areas, since the contrast in albedo between clear and cloudy conditions is greatest over oceans. In the tropics, the longwave and shortwave cloud forcings nearly cancel; therefore clouds have neither a heating nor cooling effect in these areas. Much more information is needed about clouds and radiation and their role in climate change. The largest uncertainty in climate prediction models is how to determine the radiative and physical properties of clouds. CERES observations will contribute to improving the scientific understanding of the mechanisms and factors that determine long-term climate variations and trends.

CERES Net Cloud Forcing Image

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  Image: NASA Logo NASA Official: Dr. Norman Loeb
Page Curator: Edward Kizer
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