Note: the Relationship between Numerical and Physical Models of Atmospheric Flow

There are two fundamental methods of simulating atmospheric flows physical models and mathematical models. With the first technique, scale model replicas of observed ground surface characteristics (e.g., topographic relief, buildings) are constructed and inserted into a chamber such as a wind tunnel or a water tank. The flow of air or other gases or liquids in this chamber is adjusted so as to best represent the larger scale, observed atmospheric conditions. Mathematical modeling, by contrust, utilizes such basic analysis techniques as algebra and calculus to solve directly the conservation laws of motion, heat, moisture, and other atmospheric constituents. ::