局部地形对北京“7.21”特大暴雨影响的数值研究  

Numerical study of the effects of local terrain on "7.21" extreme torrential rain in Beijing

作　　者：王宁[1] 张立凤[1] 彭军[1] 关吉平[1] 匡帅帅 

机构地区：[1]中国人民解放军理工大学气象海洋学院,南京211101

出　　处：《暴雨灾害》2014年第1期10-18,共9页Torrential Rain and Disasters

基　　金：国家自然科学基金项目(41375063);国家自然科学基金青年科学基金项目(41205074)

摘　　要：利用NCEP1°×1°再分析资料和WRF模式对2012年7月21日北京特大暴雨过程进行数值模拟,结果表明,WRF模式能够成功模拟出本次暴雨过程,特别是对100 mm以上的大暴雨也有较强的模拟能力。基于控制试验,针对北京地区复杂的地形,设计了4组地形敏感性试验。试验结果表明:北京地区局部地形的改变对暴雨落区的模拟影响不大,但对暴雨中心的分布和强度有影响,特别是西南部的局部地形对于本次暴雨过程中降水中心的落区具有很大影响,而北部和东北部的局部地形则作用不明显。进一步研究表明,北京地区西南部的局部地形主要是通过影响低层偏南风急流的流场结构,改变强辐合区和垂直运动的分布和强度,进而引起降水中心位置和强度的改变。Based on NCEP 1＆#176;＆#215;1＆#176; reanalysis data and WRF model, numerical simulation for the extreme torrential rain in Beijing on 21 July 2012 was carried out. The results show that the WRF model can successfully simulate this storm event. In particular, it even has the ability to simulate the heavy rain with 24-hour accumulated precipitation more than 100 mm. Using control run as baseline, four terrain sensitivity tests were designed. The results of terrain sensitivity tests indicate that, the changes of the local terrain of Beijing have little influence on the simu-lation for the location of the heavy rain, but have influence on the distribution and intensity of precipitation center. Especially, the local terrain in southwest side of Beijing has a significant impact on the location of precipitation center;the effect of the local terrain in north and northeast side of Beijing is not evident. Further study shows that the local terrain in southwest side of Beijing changed the intensity and distribution of strong convergence area and vertical movement mainly through influencing the structure of southerly jet in the low troposphere, which in turn caused the variation of location and intensity of precipitation center.

关 键 词：北京暴雨 数值模拟 局部地形 敏感性试验 

分 类 号：P458.121.1[天文地球—大气科学及气象学] P435