A general circulation model (GCM) is a mathematical climate model of the general circulation of a planet's atmosphere or ocean. It incorporates fluid dynamics (Navier-Stokes equations), rotation, and thermodynamics. Such a model can be analytic or can be fleshed out with computer-based numerical simulations. They undoubtedly reflect what is known of Earth's circulation, but are presumably generalized to handle alternative scenarios. They can be tailored to other particular planets and moons, and extra-solar planet study offers opportunities to use them. Example models:
GCM can also stand for global climate model, and detailed global climate models can be general circulation models.