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STAR / SMCD / EMB Radiation Budget

Radiation Budget Research

The Earth constantly receives energy in the form of radiation from the Sun. At the same time it also returns energy to space by reflecting back part of the incoming solar radiation and by emitting thermal radiation. The difference between the energy received and that returned is the earth radiation budget. The radiation budget varies both geographically and seasonally. For any given region and time the budget is usually not balanced, meaning some areas receive more energy than they return to space - for example, tropical areas - leading to warming while others lose more energy than they receive - polar regions - leading to cooling. This north-south variation in energy input to the Earth is the driving force for the major atmospheric wind patterns: the general circulation of the atmosphere. Whether the budget is balanced on a global scale and over a long period of time is a fundamental question for understanding climate change.

thumbnail of process flow chart for deriving radiation budgetRadiation at the surface are regularly observed at a number of ground sites. However, monitoring the amount and distribution of radiation on large spatial scales and at the top of the atmosphere requires continuous observations from satellites.

Scientists at STAR/SMCD/EMB are developing methodologies for retrieving the radiative energy leaving the planet and reaching the surface. These methodologies utilize measurements made from space by different, predominantly operational, Earth-observing satellites. They are based on well-known physical principles, and as such they account for the interaction of radiation with the atmosphere and the surface.