Pub. date: 2008 | Online Pub. Date: April 25, 2008 | DOI: 10.4135/9781412963893 | Print ISBN: 9781412958783 | Online ISBN: 9781412963893| Publisher:SAGE Publications, Inc.About this encyclopedia
Forced Climate Variability
STUDIES ON GLOBAL warming and climate change generally distinguish between internally generated and externally-forced climate variability. Internally generated variability is the result of processes within a system, while externally-forced variability is caused by some factors outside the system. A classic example of externally-forced climate variability is represented by the changes caused by variations in the amount and distribution of solar energy incidents on the Earth because of the differences in the solar luminosity or in the Earth's orbital parameters. The distinction between the two types of variability is not always so clear-cut, because it depends on how the boundaries of the system under examination are defined. For example, when studying or modeling the atmosphere in isolation from the rest of the climate system, changes in sea surface temperatures would be termed external forcing. Yet, in a coupled ocean/atmosphere model, variability induced in the atmosphere by variations in sea surface Internal ...