太行山对北京“7.21”特大暴雨的影响及水汽敏感性分析的数值研究  

Numerical Simulation Analysis on Impact of Taihang Mountain and Vapor Sensitivity on the 21 July 2012 Extremely Severe Rainstorm in Beijing

作　　者：王宇虹[1,2] 徐国强[2] 贾丽红 赵阳[1] 

机构地区：[1]中国气象科学研究院,北京100081 [2]中国气象局数值预报中心,北京100081 [3]新疆气象台,乌鲁木齐830002

出　　处：《气象》2015年第4期389-400,共12页Meteorological Monthly

基　　金：国家自然科学基金项目(41275104);国家重点基础研究发展计划(973计划)(2013CB430106);国家十二五科技支撑计划项目(2012BAC22B02);公益性行业(气象)科研专项(GYHY20070605)共同资助

摘　　要：运用GRAPES_Meso模式对2012年7月21—22日发生在北京地区附近的特大暴雨过程进行数值模拟和地形、水汽的敏感性试验。地形敏感性试验发现,在这次特大暴雨过程中,由于太行山北端的阻挡作用,使得气流和水汽辐合、抬升,加强了对流过程;对流层低层山前东南风和西南风、北风的辐合带增大了气旋性涡度,使东移到北京的低涡稳定维持5 h左右,对降水有明显的增幅作用;而且地形起伏和地形海拔高度对降水都有明显增幅作用,地形起伏的增幅作用较地形高度的大。水汽敏感性试验发现在这次特大暴雨过程中,水汽条件较小的变化,会导致水汽输送的明显差异,从而导致降水量显著地改变。Using the GRAPES_Meso model,the numerical simulation,topographic sensitivity experiments and vapor sensitivity experiments are carried out for the extremely severe rainfall that happened in Beijing Region from 21 to 22 July 2012.The conclusions are as follows.In the process of the severe rainstorm,the convergence of upward current and vapor is reinforced by the terrain effect of Taihang Mountain,thus reinforcing the intensity of precipitation.Due to the convergence of southeast,southwest and north winds in the lower troposphere,the intensity of cyclonic vorticity is strengthened,which is helpful for the vortex to stay above Beijing for about 5 hours.The topographic relief and altitude of mountain have great influence on rainfalls,and the effect of topographic relief is greater than the altitude.In the process of the rainstorm,small changes of the vapor condition lead to significant difference in vapor transportation.The vapor condition influences the rainfalls markedly.

关 键 词：暴雨 地形敏感性 水汽敏感性 数值试验 

分 类 号：P458.121.1[天文地球—大气科学及气象学]