自适应网格技术及其在二维动力锋生成过程模拟上的应用研究

STUDY ON APPLICATION OF ADAPTIVE GRIDS TECHNIQUE IN FRONTOGENESIS PROCESS NUMERICAL MODEL

用一个具有解析解的二维动力锋生成过程算例 ,对比自适应网格方案和固定网格方案的优劣。结果表明 :同等误差要求下 ,固定网格方案的网格点数为自适应网格方案的三倍。从时间演化上看 ,自适应网格对温带气旋的预报 ,在同等误差要求下 ,可比固定网格的预报延长 10小时以上。网格的光滑性影响有一个优化值 ;在网格适当安排情况下 ,要适度考虑正交性。从几个切面的计算结果展示了自适应网格对网格的优良安排并能抓住锋面特征结构。

A two dimensional kinematic frontogenesis process is studied for examing the use of adaptive grids in numerical model. From the comparison of the numerical results using fixed and adaptive grids and those with exact solution, it is found the adaptive runs with 1/3 fewer grid points has the same accuracy, and it can catch the structure of front because of its excellent redistribution of grid points. The results also show the adaptive runs can increase more than 10 hours for the forecasting of extratropical cyclone with the same accuracy comparison to fixed grids. There is an optimum value for grid smoothness and the error increases as the grid orthogonality is considered. [