RELATIONSHIPS BETWEEN TROPICAL PRECIPITATION AND KINEMATIC CLOUD MODELS.
Semi-annual rept. no. 1, 1 May-31 Oct 66,
TRAVELERS RESEARCH CENTER INC HARTFORD CONN
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The report gives the results of the third and most advanced experiment in a series of numerical experiments on convection. Convection is initiated by means of a buoyant bubble near the lower boundary of a two-dimensional model, and the equations of motion, continuity, thermodynamics, and cloud physics are solved numerically. The results show the bubble to rise at an accelerated rate, become saturated, and gradually turn into a precipitating cloud. Because of the complexity of the model and the resulting computer program, the experiment was restricted to eight minutes of convection simulating the early stages of development. The pressure field associated with the convection is of special interest it differs greatly from its hydrostatic counterpart and is instrumental in maintaining a downdraft outside the cloud boundary. In the updraft, the vertical pressure force opposes the buoyancy force and may become comparable in magnitude with the negative buoyancy of the liquid water. The bulk effects of the microphysics of cloud and precipitation incorporated into the convection model include autoconversion of cloud to precipitation, depletion of cloud by falling precipitation accretion, and evaporation of precipitation falling through unsaturated air. Author
- Atmospheric Physics