水汽输送的算法精度与模式暴雨预报能力的对比分析

利用中尺度模式ＭＭ４，研究了中尺度模式的暴雨模拟对于不同不汽输送方案的敏感性。采用５种平流差分格式来计算水汽的水平输送，用该模式对３次暴雨过程作了数值试验。并把不同方案的降水模拟结果与实况进行了对比。结果表明，中尺度模式的暴雨模拟对水汽输送方案十分敏感，正定高精度的Ｐｒａｔｈｅｒ格式的模拟结果最接近实况。

COMPARATIVE ANALYSIS OF ACCURACY OF MOISTURE TRANSPORT ALGORITHMS TO MODEL USEFULNESS IN HEAVY RAIN FORECASTING

The mesoscale model MM4 was adopted to investigate the sensitivity of model simulated rainstorm to moisture transport schemes. Five kinds of advection difference analogs were employed to calculate horizontal transport of vapor, followed by numerical experiments done by the model on three rainstorm events, alongside comparison of the model rainfall from different moisture schemes to the measured. Results suggest that MM4 yielded precipitation is highly sensitive to the vapor schemes and simulation from the positive definite high precision Prather scheme is closest to the observed among the five.