自适应网格模式在暴雨数值模拟中的应用

基于变分原理，自适应网格技术能根据数值模式的特点，在模式解梯度大的地区自动加密网格，提高模式的分辨率。将其应用于MM4模式中，采用多重网格法以加速自适应网格的生成。对1996年8月4日至5日发生在华北的特大台风暴雨过程，用自适应网格模式和均匀网格模式进行了数值模拟和动力诊断分析，以研究自适应网格模式在天气预报和模拟应用中的特点。试验表明，采用自适应网格后计算稳定，对所关心的天气系统及其降水的模拟精度均高于均匀网格模式，对形势场、风场的模拟精度也有明显改善。

Simulation on Storm Rainfall by Adaptive Mesh Model

Adaptive mesh technique is based on the variation method and it aims at improving the accuracy of prediction by arbitrarily densifying the grids in areas where the gradient of numerical solutions is large.By use of the multi-nested mesh method to speedup the simulation process,adaptive mesh technique is developed with MM4 model.A comparison between the adaptive mesh model and uniform mesh model is presented based on the simulation to the heave typhoon rainfall case which occurred in north of China during Aug. 4-5,1996.The results indicate that the simulation accuracy to the synoptic system and its rainfall is better in adaptive mesh model than that in the uniform mesh model.The prediction about the synoptic situation and the wind field has been improved too.