暴雨灾害
暴雨災害
폭우재해
TORRENTIAL RAIN AND DISASTERS
2014年
1期
50-57
,共8页
新一代天气雷达%风廓线雷达%闪电定位仪%强降水过程
新一代天氣雷達%風廓線雷達%閃電定位儀%彊降水過程
신일대천기뢰체%풍곽선뢰체%섬전정위의%강강수과정
new generation weather radar%wind profiler radar%lightning position finder%heavy precipitation
利用大理州新一代天气雷达(CINRAD/CC)、风廓线雷达、地面加密自动站和闪电定位仪等非常规探测资料，对2012年7月27日夜间到28日白天发生在云南省大理州的一次强降水过程进行综合分析。结果表明：500 hPa倒槽和700 hPa低涡是本次过程的主要影响系统。强降水过程可分为三个阶段，形成阶段：主要为对流性降水，雨强较强，但以单点出现，持续时间短，全州大部地区伴随有雷电；维持阶段：雷电活动明显减弱，雷达回波以层状云降水回波为主，强度未超过35 dBz，雷达径向速度场存在暖平流叠加辐合风场的特征，形成与维持两个阶段均出现了逆风区，只是范围和持续时间不同，逆风区附近及所经区域降水明显；减弱阶段：回波范围减小，强度减弱。径向速度图上，雷达探测区内为上下一致的东北气流控制。EVAD方法计算得到的散度和垂直速度信息能很好的反映强降水的动力过程，对降水的增强和维持有较好的指示意义。从风廓线雷达产品分析看，负垂直速度与降水强度有密切的对应关系。信号噪声比对降水的起止、盛衰有较好的预示作用。垂直风廓线雷达上大于8m·s-1的偏北气流向下扩展，可能存在动量下传，有利于降水强度的增大。
利用大理州新一代天氣雷達(CINRAD/CC)、風廓線雷達、地麵加密自動站和閃電定位儀等非常規探測資料，對2012年7月27日夜間到28日白天髮生在雲南省大理州的一次彊降水過程進行綜閤分析。結果錶明：500 hPa倒槽和700 hPa低渦是本次過程的主要影響繫統。彊降水過程可分為三箇階段，形成階段：主要為對流性降水，雨彊較彊，但以單點齣現，持續時間短，全州大部地區伴隨有雷電；維持階段：雷電活動明顯減弱，雷達迴波以層狀雲降水迴波為主，彊度未超過35 dBz，雷達徑嚮速度場存在暖平流疊加輻閤風場的特徵，形成與維持兩箇階段均齣現瞭逆風區，隻是範圍和持續時間不同，逆風區附近及所經區域降水明顯；減弱階段：迴波範圍減小，彊度減弱。徑嚮速度圖上，雷達探測區內為上下一緻的東北氣流控製。EVAD方法計算得到的散度和垂直速度信息能很好的反映彊降水的動力過程，對降水的增彊和維持有較好的指示意義。從風廓線雷達產品分析看，負垂直速度與降水彊度有密切的對應關繫。信號譟聲比對降水的起止、盛衰有較好的預示作用。垂直風廓線雷達上大于8m·s-1的偏北氣流嚮下擴展，可能存在動量下傳，有利于降水彊度的增大。
이용대리주신일대천기뢰체(CINRAD/CC)、풍곽선뢰체、지면가밀자동참화섬전정위의등비상규탐측자료，대2012년7월27일야간도28일백천발생재운남성대리주적일차강강수과정진행종합분석。결과표명：500 hPa도조화700 hPa저와시본차과정적주요영향계통。강강수과정가분위삼개계단，형성계단：주요위대류성강수，우강교강，단이단점출현，지속시간단，전주대부지구반수유뇌전；유지계단：뇌전활동명현감약，뢰체회파이층상운강수회파위주，강도미초과35 dBz，뢰체경향속도장존재난평류첩가복합풍장적특정，형성여유지량개계단균출현료역풍구，지시범위화지속시간불동，역풍구부근급소경구역강수명현；감약계단：회파범위감소，강도감약。경향속도도상，뢰체탐측구내위상하일치적동북기류공제。EVAD방법계산득도적산도화수직속도신식능흔호적반영강강수적동력과정，대강수적증강화유지유교호적지시의의。종풍곽선뢰체산품분석간，부수직속도여강수강도유밀절적대응관계。신호조성비대강수적기지、성쇠유교호적예시작용。수직풍곽선뢰체상대우8m·s-1적편북기류향하확전，가능존재동량하전，유리우강수강도적증대。
Unconventional observation data,such as data of the newly built Generation Weather Radar (the CINRAD/CC) in Dali, the wind profile radar, ground intensive automatically observation station and lightning position finder,are used to analyze the heavy precipitation event occurred from the night of 27 July to the day of 28 July 2012 in Dali, Yunnan Province. It is shown that the main impact factors to the event are the inverted trough in 500 hPa and low-pressure vortex in 700 hPa. The evolution of heavy precipitation event can be divided into three stag-es. In the formation stage, precipitation mainly appears as convective precipitation;rainfall intensity is strong, but precipitation cells are isolat-ed and short lived. Thunder and lightning are observed in most of the Dali area. In the maintenance phase, lightning activity significantly re-duced, and radar echo is dominated by stratiform cloud precipitation echo, which does not exceed 35 dBz. In the maintenance phase, the char-acteristics of radar radial velocity field are the superposition of warm advection and convergence wind field. Counter-wind zone appears both in the formation and maintenance stages with the differences in coverage and duration. Precipitation is significant nearby and along the path of the Counter-wind zone. In the dissipating stage, echo coverage decreases, and its intensity weakens. From the radial velocity, it is seen that the northeast airflow controls entire layer in radar detectable area. Divergence and vertical velocity calculated by EVAD can well reflect the dynamic process of the heavy precipitation, these are good indications to the precipitation enhancement and maintenance. These is a close re-lationship between negative vertical velocity and precipitation intensity from analysis of the wind profiler radar products. The signal to noise ratio can well indicate the beginning and the end of precipitation, and to its increase or decrease in intensity. The precipitation increase was closely related to the momentum transportation downward caused by greater than 8 m·s-1 northerly air-stream.
