天山地形对新疆强降水天气影响的数值模拟研究  

Numerical Smulation of Tianshan Topographic Effect on the Precipitation in Xinjiang

作　　者：马玉芬[1] 赵玲[1] 赵勇[1] 

机构地区：[1]中国气象局乌鲁木齐沙漠气象研究所,新疆乌鲁木齐830002

出　　处：《沙漠与绿洲气象》2012年第5期40-45,共6页Desert and Oasis Meteorology

基　　金：沙漠气象科学研究基金项目Sqj20080012;新疆维吾尔自治区气象局气象科技研究课题C200906;公益性行业(气象)科研专项(GYHY201006012);全球变化重大科学研究计划项目(2010CB951001)

摘　　要：2009年5月24日夜间至26日夜间,新疆境内自西向东出现了明显的降水、大风、降温天气过程。本文采用WRFV3.1模式对其进行了数值模拟,通过改变天山山脉的地形高度设计了一组敏感性试验,分析了天山地形对此次强天气过程中大风和降温的影响作用。结果表明:(1)天山山脉的地形对此次暴雨强降水天气过程的强度和落区有重要影响;随着地形的升高,雨带在天山迎风坡一侧的带状分布特征越明显,迎风坡一侧的降水量极值越大;地形的抬升作用对暴雨在山脉迎风坡一侧的降雨量有明显的增幅效应,对其雨带分布也有显著影响;(2)天山山脉对"5.25"强降水天气过程中的西南暖湿气流有明显的分流与阻挡作用。天山山脉将西南暖湿气流分为南北两支,使北支的水汽混合比极大值减小,湿区范围增大;使南支的水汽混合比极大值增大,湿区范围增大;(3)天山山脉的地形抬升作用为"5.25"强降水过程在天山山区发生暴雨天气创造了水汽的垂直上升运动条件,对昆仑山北坡暖湿气流的垂直上升运动也有一定的贡献。A rainstorm accompanied by gale and cold wave occurred from the night of May 24th to the night of May 26th, 2009 in Xinjiang. To understand the topographic effect of Tianshan Mountains upon the rainstorm, it was numerically simulated with WRFV3.1 and then a set of terrain sensitive experiments through changing the topographic height of Tianshan Mountains was designed. Some conclusions are thus drawn as follows： firstly, the topographic effect of Tianshan Mountain dominated in causes of the rainstorm over Tianshan Mountains. The higher the terrain of Tianshan, the more obvious the zonal feature of the rainfall region and the heavier the maximum precipitation volume near the against-wind mountainside. Thus Tianshan＇s topography was significant in increasing the rainfall volume around the against-wind mountainside, which also plays a great role in the distribution of rainfall region. Secondly, Tianshan Mountains was also important to the warm humidity from the southwest, which not only obstructed the air stream＇s northeastward moving, but also divided the air stream into two parts and further made the north part become weaker and widen the wet zone while the south part stronger and widen contributed to the upward movement of warm and wet Mountains and Kunlun Mountains, which created the process. the wet zone. Thirdly, Tianshan＇s topography airflow around the north side of both Tianshan vertical ascendance condition for the rainfall

关 键 词：数值模拟 地形敏感性试验 暴雨 

分 类 号：P456.7[天文地球—大气科学及气象学]