气象与环境学报
氣象與環境學報
기상여배경학보
JOURNAL OF METEOROLOGY AND ENVIRONMENT
2012年
6期
19-24
,共6页
局地强降水%中小尺度系统%中气旋
跼地彊降水%中小呎度繫統%中氣鏇
국지강강수%중소척도계통%중기선
Local heavy precipitation%Meso-small scale system%Mesocyclone
利用Doppler雷达产品,结合高时空分辨率T639再分析资料,对2010年6月22日发生在天山北坡中部,石河子南部山区罕见局地强降水的中小尺度系统特征和强降水发生时间与落区进行分析。结果表明:西伯利亚至巴尔喀什湖的冷低压东南象限分裂出的中尺度短波,是造成“2010622”罕见局地强降水的直接影响系统。近低层至地面的中尺度切变线、辐合线与冷锋是局地强降水发生的触发机制。近低层存在着强盛的西南与东南暖湿气流的输送及其在天山山前的强烈辐合,为南部山区强降水的发生提供了有效水汽和不稳定能量条件。多个中-γ对流单体沿特殊地形滚动更叠是局地强降水天气落区形成的直接原因。中气旋的出现对局地强降水发生有较好的先兆性和指示意义。强降水区发生在回波强度大于50dBz、回波顶高度大于5km和垂直累积液态水含量大于45kg·m^-2以及中气旋的重合区域内。可由中气旋提前20min预警短时局地强降水的发生。
利用Doppler雷達產品,結閤高時空分辨率T639再分析資料,對2010年6月22日髮生在天山北坡中部,石河子南部山區罕見跼地彊降水的中小呎度繫統特徵和彊降水髮生時間與落區進行分析。結果錶明:西伯利亞至巴爾喀什湖的冷低壓東南象限分裂齣的中呎度短波,是造成“2010622”罕見跼地彊降水的直接影響繫統。近低層至地麵的中呎度切變線、輻閤線與冷鋒是跼地彊降水髮生的觸髮機製。近低層存在著彊盛的西南與東南暖濕氣流的輸送及其在天山山前的彊烈輻閤,為南部山區彊降水的髮生提供瞭有效水汽和不穩定能量條件。多箇中-γ對流單體沿特殊地形滾動更疊是跼地彊降水天氣落區形成的直接原因。中氣鏇的齣現對跼地彊降水髮生有較好的先兆性和指示意義。彊降水區髮生在迴波彊度大于50dBz、迴波頂高度大于5km和垂直纍積液態水含量大于45kg·m^-2以及中氣鏇的重閤區域內。可由中氣鏇提前20min預警短時跼地彊降水的髮生。
이용Doppler뢰체산품,결합고시공분변솔T639재분석자료,대2010년6월22일발생재천산북파중부,석하자남부산구한견국지강강수적중소척도계통특정화강강수발생시간여락구진행분석。결과표명:서백리아지파이객십호적랭저압동남상한분렬출적중척도단파,시조성“2010622”한견국지강강수적직접영향계통。근저층지지면적중척도절변선、복합선여랭봉시국지강강수발생적촉발궤제。근저층존재착강성적서남여동남난습기류적수송급기재천산산전적강렬복합,위남부산구강강수적발생제공료유효수기화불은정능량조건。다개중-γ대류단체연특수지형곤동경첩시국지강강수천기락구형성적직접원인。중기선적출현대국지강강수발생유교호적선조성화지시의의。강강수구발생재회파강도대우50dBz、회파정고도대우5km화수직루적액태수함량대우45kg·m^-2이급중기선적중합구역내。가유중기선제전20min예경단시국지강강수적발생。
Abstract:Based on the Doppler radar products and T639 reanalysis data, small-scale system characteristics of a rare heavy rain on June 22,2010 in the south of Shihezi and its occurrence time as well as falling area were ana- lyzed. The results show that mesoscale short wave split from cold low-pressure from Siberia to Lake Balkhash is the direct influencing system of this process. The middle scale shear line from low level to ground and convergence line as well as cold front are the trigger mechanism for the local heavy rain. There is the transportation of strong southwest and southeast warm-wet air flow and their strong convergence in front of the mountain near low level, which provides the effective moisture and unstable energy for this process. Multiple-γ convective cells roll and change along the special topography, which are the direct reasons forming failing areas of the local strong rain. The occurrence of meso-cyclone is indicative to the heavy rain. The heavy precipitation occurs in the superposition are- as where the echo intensity is more than 50 dBz, the echo top height exceeds 5 km, vertical accumulated liquid wa- ter content is above 45 kg·m^-2 and it exists in the mesocyclone. It is in advance about 20 rain for warning of short- time strong precipitation using mesocyclone.