Wind and thermodynamic retrieval of mesoscale convective systems

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Precipitation systems which cause a heavy rainfall or heavy snowfall are mesoscale convective systems. It is important to develop a method to retrieve wind and thermodynamic variable in the mesoscale convective system as well as to develop a numerical model to resolve a convective cloud.In this study, we develop a retrieval method of wind from a Doppler radar observation and a cloud resolving numerical model. In order to simulate a mesoscale convective system, it is necessary to calculate by a parallel computer in a large computational domain with a high resolution.The cloud model that we are developing is formulated in the non-hydrostatic and compressible equation system. Cloud physics is formulated by a bulk method of warm rain at present and cold rain will be included in the future. A large computational domain (order of 100km) is necessary for the simulation of thunderstorm with a very high resolution (order of less than 1km).In the development of the high resolution cloud model, we tested it with respect to several types of phenomena. In a dry system, the mountain waves and the Kelvin-Helmholtz billows are tested and compared with results obtained by other models. In a wet system, we chose a tornado-producing super cell observed on 24 September 1999 in Japan. The model successfully resolved the vortex of the tornado with the parent super cell.In the future, we will extend the model to include detailed cloud physical processes which resolve size distributions of hydro-meteors.