Theoretical Studies of Squall-Line Type and Tornado-Like Disturbances in the Atmosphere.

A multi-two-dimensional squall line model is constructed by approximating the three-dimensional variable by the sum of three components which can be considered as its projections in the three orthogonal planes when taken alone, and use the maturely dependent set of two-dimensional equations to represent the three-dimensional flow. Condensation and precipitation processes are also included. A wide variety of numerical simulations may be performed with this model. The question of the upshear slope of the squall line type thunderstorm is investigated separately by using the pure two-dimensional version of the model. Influence of the fictitious side boundaries is minimized by the use of a radiation condition based on the phase velocity of the disturbance. The question of the conditions that lead to the development of the two-cell type vortex motion with descending motion at the center is attacked by extending Kuos similarity solutions to higher order in z. Author