耦合不同陆面方案的WRF模式对“8.8”舟曲暴雨过程的模拟

利用NCEP每6 h一次的1°×1°格点资料和中尺度模式WRF(V3.2),选用不同的陆面参数化方案,对2010年8月7—8日发生在甘肃舟曲的一次西北地区特大暴雨天气过程进行数值模拟试验。结果表明,此次暴雨过程数值模拟的准确率对陆面参数化方案的选择比较敏感。在WRF模式中,耦合陆面方案比不耦合陆面方案对暴雨的模拟效果更好,耦合陆面方案所模拟的降水分布、地表通量以及地面气象要素都与实况更加接近。耦合不同的陆面方案模拟的降水以及感热通量、潜热通量都存在较大的差别,但是采用不同的陆面方案模拟的地表温度和水汽差别并不大。总体而言,采用PX陆面方案对降水的模拟效果比采用其他方案都合理,与实况最接近。

Numeric Simulations of Rainstorm in ZhouQu County on 8 August 2010 Using the WRF Model with Different Land Surface Schemes

The numeric simulation experiments coupled with different land surface parameterization schemes were carried out on the rainstorm process in ZhouQu county during 7-8 August 2010 by using NCEP 1°×1° data with 6 h intervals and WRF V3.2 meso-seale model. The result showed that the forecasting accuracy of numeric simulation was sensitive to the different land surface parameterization schemes. By coupling the land surface scheme, the simulation effect could be improved on precipitation simulation, surface meteorological elements and surface flux significantly. The simulated precipitation, sensible heat flux and latent heat flux presented obvious differences when the different land surface schemes were used in WRF model. However, the simulated surface temperature and water vapor presented little differences when the different schemes were chosen. Comparing all the simulation results, the PX scheme orovided more reasonable results than the others.