Numerical Simulations of a Mountain Thunderstorm. A Comparison with Doppler RadarObservations

摘要

A two-dimensional, non-hydrostatic cloud model was used to isolate the processesand initial conditions most important in the initiation and development of a small mountain thunderstorm. Six numerical simulations were conducted--one control and five experiments. The control simulation was conducted with realistic initial conditions and physical processes. The simulation's accuracy was evaluated by comparison to multiple-Doppler radar analyses of a storm that occurred on 31 July, 1984 near Langmuir Laboratory, New Mexico and to a microphysical retrieval conducted for a different, but similar storm. The other five simulations were conducted to test the sensitivity of the simulated storms to the initial wind profile, the lack of solar heating, restriction to warm rain processes, and the initial moisture profile. Comparison of the evolution of the control's simulated storm with observation sand with the microphysical retrieval show that the simulation accurately captured the major features observed by the radars and accurately depicted the microphysical evolution of the storm cells. The results of the numerical experiments showed the following conditions and processes to be most important (in descending order) to the development and maintenance of the storm: solar heating, ice phase microphysical processes, environmental wind profile, and low-level moisture profile. The environmental wind profile was the single most important factor in the convective initiation location.