气象与环境学报
氣象與環境學報
기상여배경학보
JOURNAL OF METEOROLOGY AND ENVIRONMENT
2012年
4期
1-7
,共7页
西南涡暴雨%降水运动%LAPS中尺度分析%凝结函数降水率%水汽%云水和云冰通量散度%对流可降水量
西南渦暴雨%降水運動%LAPS中呎度分析%凝結函數降水率%水汽%雲水和雲冰通量散度%對流可降水量
서남와폭우%강수운동%LAPS중척도분석%응결함수강수솔%수기%운수화운빙통량산도%대류가강수량
Torrential rain caused by a southuest vortex%precipitation motion%Meso-scale analysis from LAPS%Condensation function precipitation rate%Water vapor%Cloud moisture and cloud ice flux divergence%Covnective precipitable precipitation
采用LAPS中尺度分析模式大气资料,对2008年7月一次西南涡暴雨过程进行天气学降水运动的中尺度诊断计算与分析。诊断计算包括：可降水量、层结不稳定能量、对流可降水量、水汽权重平均风速、水汽通量散度、云水、云冰总量及其通量散度和垂直速度与凝结函数降水率等。结果表明：＂西南涡—切变线＂系统的暴雨发生在暖湿气团与变性冷气团之间的中尺度风场辐合上升运动区,中尺度雨团发生在层结不稳定的暖湿气团一侧。计算的中尺度垂直运动与凝结函数降水率场,降水率为暴雨到特大暴雨。计算的水汽通量辐合降水率与凝结函数降水率不会完全重合,且水汽通量辐合既可致中尺度＂雨＂,又可成大尺度＂云＂,并且云水、云冰通量辐合/辐散,可解释为它们的＂正＂/＂负＂碰并增长,而碰并增长产生水凝物增量（降水率）促成大暴雨。因此,在凝结函数降水率场中产生的中、小尺度对流雨团,加上水汽与云水、云冰通量辐合及其碰并增长,并且借助层结不稳定能量释放和可能产生的强迫＂次级环流＂及水汽与云水、云冰输送,是＂西南涡—切变线＂系统造成襄樊特大暴雨的天气学成因。
採用LAPS中呎度分析模式大氣資料,對2008年7月一次西南渦暴雨過程進行天氣學降水運動的中呎度診斷計算與分析。診斷計算包括：可降水量、層結不穩定能量、對流可降水量、水汽權重平均風速、水汽通量散度、雲水、雲冰總量及其通量散度和垂直速度與凝結函數降水率等。結果錶明：＂西南渦—切變線＂繫統的暴雨髮生在暖濕氣糰與變性冷氣糰之間的中呎度風場輻閤上升運動區,中呎度雨糰髮生在層結不穩定的暖濕氣糰一側。計算的中呎度垂直運動與凝結函數降水率場,降水率為暴雨到特大暴雨。計算的水汽通量輻閤降水率與凝結函數降水率不會完全重閤,且水汽通量輻閤既可緻中呎度＂雨＂,又可成大呎度＂雲＂,併且雲水、雲冰通量輻閤/輻散,可解釋為它們的＂正＂/＂負＂踫併增長,而踫併增長產生水凝物增量（降水率）促成大暴雨。因此,在凝結函數降水率場中產生的中、小呎度對流雨糰,加上水汽與雲水、雲冰通量輻閤及其踫併增長,併且藉助層結不穩定能量釋放和可能產生的彊迫＂次級環流＂及水汽與雲水、雲冰輸送,是＂西南渦—切變線＂繫統造成襄樊特大暴雨的天氣學成因。
채용LAPS중척도분석모식대기자료,대2008년7월일차서남와폭우과정진행천기학강수운동적중척도진단계산여분석。진단계산포괄：가강수량、층결불은정능량、대류가강수량、수기권중평균풍속、수기통량산도、운수、운빙총량급기통량산도화수직속도여응결함수강수솔등。결과표명：＂서남와—절변선＂계통적폭우발생재난습기단여변성랭기단지간적중척도풍장복합상승운동구,중척도우단발생재층결불은정적난습기단일측。계산적중척도수직운동여응결함수강수솔장,강수솔위폭우도특대폭우。계산적수기통량복합강수솔여응결함수강수솔불회완전중합,차수기통량복합기가치중척도＂우＂,우가성대척도＂운＂,병차운수、운빙통량복합/복산,가해석위타문적＂정＂/＂부＂팽병증장,이팽병증장산생수응물증량（강수솔）촉성대폭우。인차,재응결함수강수솔장중산생적중、소척도대류우단,가상수기여운수、운빙통량복합급기팽병증장,병차차조층결불은정능량석방화가능산생적강박＂차급배류＂급수기여운수、운빙수송,시＂서남와—절변선＂계통조성양번특대폭우적천기학성인。
Based on the atmospheric data from LAPS(local analysis and prediction system),a torrential rain process caused by a southwest vortex in July 2008 in China was analyzed.The probable precipitation,instable energy of stratification,convective precipitable precipitation,mean wind speed of water vapor weight,water vapor flux divergence,the total cloud water and cloud ice and its flux divergence,vertical velocity and condensation function precipitation rates and so on were calculated and diagnosed.The results indicate that the torrential rain from"a southwest vortex shear line system"occurs in the ascending areas due to meso-scale wind field convergence between the warm-wet air mass and cold air mass and is located on the side of warm-wet air mass of unstable stratification.The calculation of the meso-scale vertical motion and the field of the condensation function precipitation rate show that the grade of precipitation rate reaches the heavy rain to rainstorm.The calculated precipitation rate of water vapor flux convergence is not entirely consistent with that of the condensation function.The water vapor flux convergence not only produces meso-scale"rain",but also large-scale"cloud",and cloud moisture and cloud ice flux convergence or divergence is their positive or negative"collection growth"and then forms incremental hydrometeors(precipitation rate),which helps to produce a heavy rain.Thus,the synoptic reasons for the heavy rain in Xiangfan include the meso-scale and small-scale convective rain mass produced by the field of the condensation function precipitation rate,the water vapor,the flux convergence of cloud moisture and cloud ice,the cloud particle"collection growth",the energy release from unstable stratification,the possible"secondary circulation"stimulated by forcing,and the transportation of water vapor,cloud moisture and cloud ice.
