干旱气象
榦旱氣象
간한기상
Journal of Arid Meteorology
2015年
4期
616-625,658
,共11页
张晓露%李照荣%周筠珺%褚晓菊
張曉露%李照榮%週筠珺%褚曉菊
장효로%리조영%주균군%저효국
西北地区东部暴雨%切变线%诊断分析%数值模拟%地形作用
西北地區東部暴雨%切變線%診斷分析%數值模擬%地形作用
서북지구동부폭우%절변선%진단분석%수치모의%지형작용
heavy rainfall in east of northwest China%shear line%diagnostic analysis%numerical simulation%topographic effect
利用地面区域站降水量资料、NCEP FNL再分析资料、风云卫星数据产品以及WRF数值模拟结果,对2013年7月7~9日发生在西北地区东部的一次暴雨过程进行诊断分析。结果表明:此次暴雨是一次典型的副热带高压(简称副高)西北侧西南气流型暴雨,西风槽和高原槽发展东移,配合副高外围的西南气流及低层低涡切变是造成此次暴雨的主要影响系统。高低空急流的耦合、充沛的水汽聚集、较强的动力作用以及大气层结的不稳定等对此次强降水的发展起到促进作用。WRF模式对此次复杂地形下的暴雨有较好的模拟能力,模拟的降水与实况相吻合,风场、比湿、涡度、CAPE、垂直速度等物理量对此次降水过程有较好的反映。低层气流经喇叭口地形时被抬升并辐合,再配合丰富的水汽场,使得降雨过程得以维持和发展。
利用地麵區域站降水量資料、NCEP FNL再分析資料、風雲衛星數據產品以及WRF數值模擬結果,對2013年7月7~9日髮生在西北地區東部的一次暴雨過程進行診斷分析。結果錶明:此次暴雨是一次典型的副熱帶高壓(簡稱副高)西北側西南氣流型暴雨,西風槽和高原槽髮展東移,配閤副高外圍的西南氣流及低層低渦切變是造成此次暴雨的主要影響繫統。高低空急流的耦閤、充沛的水汽聚集、較彊的動力作用以及大氣層結的不穩定等對此次彊降水的髮展起到促進作用。WRF模式對此次複雜地形下的暴雨有較好的模擬能力,模擬的降水與實況相吻閤,風場、比濕、渦度、CAPE、垂直速度等物理量對此次降水過程有較好的反映。低層氣流經喇叭口地形時被抬升併輻閤,再配閤豐富的水汽場,使得降雨過程得以維持和髮展。
이용지면구역참강수량자료、NCEP FNL재분석자료、풍운위성수거산품이급WRF수치모의결과,대2013년7월7~9일발생재서북지구동부적일차폭우과정진행진단분석。결과표명:차차폭우시일차전형적부열대고압(간칭부고)서북측서남기류형폭우,서풍조화고원조발전동이,배합부고외위적서남기류급저층저와절변시조성차차폭우적주요영향계통。고저공급류적우합、충패적수기취집、교강적동력작용이급대기층결적불은정등대차차강강수적발전기도촉진작용。WRF모식대차차복잡지형하적폭우유교호적모의능력,모의적강수여실황상문합,풍장、비습、와도、CAPE、수직속도등물리량대차차강수과정유교호적반영。저층기류경나팔구지형시피태승병복합,재배합봉부적수기장,사득강우과정득이유지화발전。
Based on the hourly precipitation from weather stations,NCEP FNL reanalysis data with 0. 1° × 0. 1° resolution,products of FY-2E satellite and output results from Weather Research and Forecasting Model(WRF),the heavy rainfall from 7 to 9 July 2013 in east of northwest China was diagnosed. The results showed that the rainstorm was a typical southwesterly airflow rainfall process which located in northwest of subtropical high system. The development and movement of the westerly trough and plateau trough,cooperating with the southwesterly airflow and the vortex shear line in low level,were main influence systems of heavy rainfall. The coupling of up-per and lower jets,the abundant water vapor together,the stronger dynamic effect and the instable atmospheric stratification facilitated the development of the heavy rainfall. The hourly evolution of TBB from FY-2E was consistent with that of rainfall intensity,when the rainfall increased dramatically at 14:00 BST on 8 July 2013,the TBB reduced to below -45℃ in east of northwest China. The model of WRF had a better capacity to simulate the weather process of rainstorm under complicated terrain. The evolution and magnitude of rainfall simulated by WRF from 08:00 BST 8 to 08:00 BST 9 July 2013 was similar to the observation,and the centre rainfall located in Qingyang of Gansu Province. The simulated physical quantities of wind field,specific humidity,vorticity,CAPE and vertical veloci-ty could well reflect the process of the heavy rainfall event. The low-level airflows were lifted and converged via the trumpet-shaped topography,which caused the increasing of cyclone and enhancing of vertical motion,cooperated with abundant water vapor,eventually caused the enhancement of heavy rainfall. Therefore,the simulated results by WRF model could be used to analyze the structure ofβ-scale rainfall system under rough topography,which could fill the lack of observation data.