利用WRF中尺度数值预报模式,选用七种微物理方案及网格嵌套技术分别与Kain—Fritsch(new Eta)、Betts—Miller—Janjic、Grell—Devenyi(简称KF、BMJ、GD方案)三种积云对流参数方案匹配,对2007年6月1-2日湖南南部的暴雨过程进行了模拟试验。模拟结果表明:选用Lin等微物理方案和三种积云方案,采用20km的格点分辨率,基本上可以模拟这场暴雨的范围,且采用刚格嵌套技术的模拟结果优于未采用嵌套的模拟结果;其中KF方案模拟的强降水位置、强度与实况比较接近;BMJ方案模拟的强降水范围偏大、强度偏强,位置偏南,上述两种方案都不同程度地存在着虚假的暴雨中心;GD方案模拟的强降水范围、强度均偏小。
A heavy rainfall during June 1-2, 2007 in Hunan province was simulated using the weather research and forecast modeling system(WRF). The study was carried out with three cumulus parameterization schemes, Kain-Fritsch(KF), Betts-Miller-Janjic(BMJ) and Grell-Devenyi(GD), respectively. The project with Lin et al.'s microphysics and the three schemes above was involved in this study, together with a 20-kin gridpoint resolution. The results indicated that the location of heavy rainfall areas roughly match the observation and better simulations are shown with the technique of 2-way gridpoint nesting than with the one without. By comparison, the KF scheme is closer to reality in location departure and intensity of heavy rainfall while the BMJ scheme reveals larger area and higher intensity but more southward location of the severe precipitation, though both of them give false centers of torrential rain; the intensity and area of heavy rainfall is weaker and smaller, respectively, for the GD scheme.