General Circulation Models (GCMs) of the Atmosphere

General circulation models (GCMs) of the atmosphere

A) produce very specific results as to time and place.
B) are now in operation at over a dozen places in the United States.
C) are based on statistical three-dimensional boxes that characterize portions of the atmosphere and ocean in terms of climate-related variables.
D) are essentially unrelated to mathematical models originally established for forecasting weather.