What’s in a global climate model? The Community Climate System Model (CCSM version 3) that is run with the supercomputer at the National Center for Atmospheric Research incorporates data about all of the natural processes shown in this diagram to simulate Earth’s complex climate system.
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How Climate Models Work
In a global climate model (GCM), hundreds of mathematical equations, which describe Earth processes and how Earth processes are interrelated, are processed using supercomputers. Usually this is done in order to make climate predictions for one or more centuries into the future; sometimes models are run backwards to examine climates of the geologic past. The GCMs represent natural processes via mathematical equations in a three-dimensional grid that covers the surface of the modeled Earth and extends upward in layers through the modeled atmosphere. At every intersection in the model’s grid the model calculates the atmospheric processes that are going on through the timeframe of the model’s run. Small processes that happen between a model’s grid points cannot be “seen” in the model results, but they can be accounted for in other ways. Some models have wide spacing in the grid and, thus, fewer points where the model calculates. These run faster and are useful when less detail is needed. Some models have very closely spaced grid points. These produce much more detailed simulations and require more computing time.
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