耦合不同陆面过程对江西南部一次暖区特大暴雨过程的模拟试验

Study on a Warm Sector Heavy Rainfall Event in Northern Jiangxi with Different Land Surface Processes

利用WRF V模式耦合4个陆面过程对2015年5月18—19日江西南部暖区特大暴雨进行了模拟,以检验陆面过程对暴雨过程的影响;在此基础上,又进行了地表通量敏感性试验,以检验地面扰动通量对降水的影响。结果表明,各方案模拟的降水范围、雨带走向以及降水中心位置与实况都比较相似,但是降水强度大小与陆面过程的选择存在一定的差异。其中,WRF模式耦合NOAH方案模拟的降水中心、降水强度和累积降水量均能够较好地反映这次暴雨过程的发展。感热和潜热通量在暖区暴雨中是维持降水持续的主要能量输送,对暴雨中心强度和位置变化的影响,潜热通量比感热通量发挥了更重要的作用。来自地面水汽蒸发所释放的潜热以及水汽抬升和辐合释放的潜能为维持暴雨强度提供了重要的能量支撑。

To examine the effects of land surface processes on heavy rainstorm processes,the numerical simulation of the heavy rainstorm occurred in the southern Jiangxi from May 18 to 19,2015 was carried out by coupling four land surface processes with WRF V model;on this basis,the sensitivity test of surface flux was carried out to test the effect of ground disturbance flux on precipitation.The results showed that the simulated precipitation range,the direction of the rain belt and the location were similar to the actual ones,however,the different land surface process presented the different precipitation intensity.The simulated precipitation center,precipitation intensity and cumulative precipitation coupled with NOAH scheme can better reflect the development of the rainstorm process.In the flux sensitivity test,the sensible and latent heat fluxes were the main energy transfer to maintain the duration of precipitation in the warm zone.The variation of the position and intensity of storm center indicated that the latent heat flux was more important than the heat flux.The latent heat released from the evaporation of ground water vapor and the potential energy for uplift and convergence of water vapor provided important energy support for the sustaining rainstorm intensity.