WRF模式陆面参数扰动对一次西北暴雨影响的数值模拟  

Numerical Simulation of Effect of WRF Land Surface Parameter Disturbance on a Rainstorm in Northwest China

作　　者：李安泰[1,2] 何宏让[1] 张云[1] 

机构地区：[1]解放军理工大学气象学院 [2]96363部队34分队

出　　处：《高原气象》2012年第1期65-75,共11页Plateau Meteorology

基　　金：国家自然科学基金项目(41005074;40705020)资助

摘　　要：利用NCEP每6h一次的1°×1°再分析资料和中尺度模式WRF V3.1,以2005年7月1～2日发生在甘肃东南部的一次暴雨天气为例,根据NOAH陆面方案中土壤最大容积水含量(MAXSMC)初始扰动对此次暴雨进行了敏感性数值模拟试验。结果表明,此次暴雨对陆面参数MAXSMC扰动比较敏感,MAXSMC初值减少20%,模拟的降水与实况更接近,而增大MAXSMC则对降水的影响不大;浅层土壤湿度、低层气象要素以及地表通量均对MAXSMC扰动有一定的敏感性,但是由于不同的下垫面类型,其敏感性也存在明显的差异;地表通量的直接输送和由低层不稳定所导致的间接水汽输送的变化,对降水的影响是最主要的。在不同的区域,由于下垫面性质的差异导致二者所占的比例存在差异,故模拟的降水会出现完全不同的走势。To test the sensitivity of the rainstorm to the disturbance of NOAH land surface parameter MAXSMC in Northwest China,the rainstorm process in southeast of Gansu during 1～2 July of 2005 are numerically simulated using NCEP 1°×1° reanalysis data and WRF V3.1 mesoscale model.The results indicate that the rianstorm is more sensitive to the disturbance of the parameter MAXSMC（maximum volumetric soil water）,the increased MAXSMC will not improve simulation of precipitation,and if the initial value decreases by 20%,the simulated precipitation will be more close to the observation.The soil moisture in shallow layer,lower-level meteorological factors and surface flux to disturbance MAXSMC are of certain sensitive,but the sensitivity is significant different because of the various underlying surfaces.The most important influence on rainstorm is the changes of the direct transport of surface flux and indirect water vapor transport caused by lower level instability,and due to the different proportions of direct transport of surface flux and indirect water vapor transport resulted from underlying surface properties,precipitation will appear completely different trends in different regions.

关 键 词：西北地区 陆面参数 暴雨 数值模拟 

分 类 号：P458.121.1[天文地球—大气科学及气象学]