中尺度模式边界层方案对华中区域降水预报的对比试验

Comparison of precipitation forecast in central China with different boundary layer parameterizations

选用华中区域中尺度模式中的ACM2、YSU、MYJ三种边界层参数化方案,对2012年5—7月进行降水模拟检验。通过比较三种方案模拟降水的总量分布,表明三种方案能够体现出累积降水的整体分布特征,但存在细节差异,降水TS评分(Ts)和BS偏差(Bs)统计显示ACM2的预报性能优于YSU方案和MYJ方案。大气温湿结构则体现了MYJ方案湍流输送较弱的特点,ACM2和YSU方案因使用非局地闭合理论,模拟结果相近。此外对一次西南低涡暴雨过程进行了分析,结果表明:ACM2方案对低涡移动路径、强度及造成的降水量的总体模拟效果最好。

By using three different PBL schemes （YSU, ACM2, MYJ） in numerical prediction system it, central China, the precipitation fore cast from May to July in 2012 is analyzed. Comparisons of the distribution of total rainfall indicate that all three PBL schemes can result in the overall characteristics of precipitation distribution, but exhibiting differenees in detail. The TS scores and Biases scores show the, the ACM2 are better than YSU and MYJ. The atmospheric temperature and moisture structures reflect a weak turblent mixing in the MYJ, and resuhs of the ACM2 and YSU are similar because they use nonlocal closure theory. A southwesl vortex is tested, where ACM2 performs the best in pre- cipitation, track and intensity of the southwest vortex.