不同初值和降水方案对一次西南涡暴雨过程的中尺度模拟与分析  

Meso-scale Numerical Simulation and Analysis on a Southwest Vortex Rainstorm by Different Initial Fields and Precipitation Schemes

作　　者：唐永兰[1,2] 辜旭赞[2] 张兵[2] 

机构地区：[1]中国气象科学研究院,北京100081 [2]中国气象局武汉暴雨研究所,武汉430074

出　　处：《暴雨灾害》2011年第4期335-342,共8页Torrential Rain and Disasters

基　　金：公益性行业(气象)科研专项(GYHY200906010;GYHY201106003)

摘　　要：用GRAPES_meso数值模式和LAPS中尺度局地分析资料,对2.5 km和5 km两种分辨率,采用NCEP 3-class降水方案和2种混合降水方案,给定不同的spin up时间,设计18种组合方案,对2008年7月一次西南涡暴雨过程做数值模拟。在模拟可信的前提下,对西南涡暴雨的天气学成因进行分析。模拟试验表明,LAPS初值场经过3~6 h的spin up＂磨合＂,可获得比较协调的物理量场,NCEP 3-class方案用于2.5 km分辨率的模拟效果较好。模拟也表明,直接用NCEP再分析资料做初值场,较用以NCEP资料为背景场做实时中尺度观测资料融合的LAPS初值场,后者较前者模拟的中尺度对流雨团有改进,模拟的雨带与实况更接近,且模拟的垂直速度,在积分前4 h（spin up时间）有优势,改善了最初降水发生的动力结构。模拟结果的诊断计算与分析表明,该＂西南涡—切变线＂暴雨发生在以系统性上升运动为背景的高湿区中,由于中、小尺度重力波垂直运动而产生的中尺度对流性（雨团）降水。Using GRAPES_meso numerical model and the LAPS meso-scale data with 2.5 km and 5 km resolution,a case of southwest vortex rainstorm in July 2008 is numerically simulated with 18 test programs designed with three kinds of precipitation schemes（NCEP 3-class and two kinds of mixed precipitation schemes） and given spin up times.On the premise that the simulated results were creditable the synoptic cause of the rainstorm were analyzed.The results show that LAPS initial field can get a coordinated physical field after 3-6 h spin up ＂running in＂ and the simulation result of NCEP 3-class scheme is better for the 2.5 km resolution.The simulation result also shows that the simulation results made using LAPS data as initial field are better than that using NCEP reanalysis data,that is,simulated meso-scale convective rain clusters have improvement,the simulated rain belt is closer to the observation,and the simulated vertical velocity has an advantage of 4h（spin up time） before the initial integration,which improves the power structure of initial precipitation.Diagnostic analysis of simulation results shows that the ＂southwest vortex-shear line＂ storm happens in a high humidity area with the background of systematic upward motion,and is convective（rain cluster） precipitation due to vertical movement of the meso-scale or small-scale gravity waves.

关 键 词：GRAPES_MESO LAPS中尺度分析 西南涡暴雨 中尺度数值模拟 NCEP 3-class降水方案 混合降水方案 诊断分析 spin up时间 

分 类 号：P458.121.1[天文地球—大气科学及气象学]