暴雨灾害
暴雨災害
폭우재해
TORRENTIAL RAIN AND DISASTERS
2013年
4期
338-345
,共8页
张勇%刘德%张亚萍%方德贤
張勇%劉德%張亞萍%方德賢
장용%류덕%장아평%방덕현
灾害性大风%地面辐合线%地面辐散区%闪电密度%下击暴流
災害性大風%地麵輻閤線%地麵輻散區%閃電密度%下擊暴流
재해성대풍%지면복합선%지면복산구%섬전밀도%하격폭류
disastrous gale%surface convergence line%surface divergence zone%lightning density%downburst
利用常规观测资料、地面加密自动站资料、ADTD地闪资料和天气雷达资料,分析了2011年7月23日重庆西部一次强对流风暴过程的中尺度特征。结果显示:(1)此次强对流天气是在“两高一低”环流背景下发生的,强的层结不稳定、低层水汽充足、大的下沉不稳定能量及0-6 km中等强度垂直风切变为其提供了有利的环境条件。(2)地面灾害性大风主要集中在地面强降水及地闪密度中心附近,地面观测到与地面大风相联系的辐合线、辐散区、冷池及雷暴高压等中尺度特征,地闪以负地闪为主,负、正地闪之比约为101:1。(3)造成极端大风和短时强降水的强对流风暴在雷达回波图上具有明显的阵风锋、回波悬垂、弱回波区和有界弱回波区等特征;在径向速度图上,具有明显的中气旋、辐散区、大风区、前侧入流、高层辐散和低层辐合等特征,这些特征对地面灾害性大风具有一定的监测预警意义。
利用常規觀測資料、地麵加密自動站資料、ADTD地閃資料和天氣雷達資料,分析瞭2011年7月23日重慶西部一次彊對流風暴過程的中呎度特徵。結果顯示:(1)此次彊對流天氣是在“兩高一低”環流揹景下髮生的,彊的層結不穩定、低層水汽充足、大的下沉不穩定能量及0-6 km中等彊度垂直風切變為其提供瞭有利的環境條件。(2)地麵災害性大風主要集中在地麵彊降水及地閃密度中心附近,地麵觀測到與地麵大風相聯繫的輻閤線、輻散區、冷池及雷暴高壓等中呎度特徵,地閃以負地閃為主,負、正地閃之比約為101:1。(3)造成極耑大風和短時彊降水的彊對流風暴在雷達迴波圖上具有明顯的陣風鋒、迴波懸垂、弱迴波區和有界弱迴波區等特徵;在徑嚮速度圖上,具有明顯的中氣鏇、輻散區、大風區、前側入流、高層輻散和低層輻閤等特徵,這些特徵對地麵災害性大風具有一定的鑑測預警意義。
이용상규관측자료、지면가밀자동참자료、ADTD지섬자료화천기뢰체자료,분석료2011년7월23일중경서부일차강대류풍폭과정적중척도특정。결과현시:(1)차차강대류천기시재“량고일저”배류배경하발생적,강적층결불은정、저층수기충족、대적하침불은정능량급0-6 km중등강도수직풍절변위기제공료유리적배경조건。(2)지면재해성대풍주요집중재지면강강수급지섬밀도중심부근,지면관측도여지면대풍상련계적복합선、복산구、랭지급뇌폭고압등중척도특정,지섬이부지섬위주,부、정지섬지비약위101:1。(3)조성겁단대풍화단시강강수적강대류풍폭재뢰체회파도상구유명현적진풍봉、회파현수、약회파구화유계약회파구등특정;재경향속도도상,구유명현적중기선、복산구、대풍구、전측입류、고층복산화저층복합등특정,저사특정대지면재해성대풍구유일정적감측예경의의。
Based on data from conventional observations, intensive network of automatic weather stations (AWS), ADTD lightning instru-ment and weather radar, we analyzed the mesoscale characteristics of a severe convective storm event occurred in western Chongqing on 23 July 2011. The main results are as follows. (1) The event occurred under the condition of a cold low circulation between the Tibet high and the subtropical high. Several factors such as strong unstable stratification, sufficient water vapor in the low level, large downdraft convective avail-able potential energy (DCAPE) and moderate vertical shear in 0-6 km are favorable to the development of the storm. (2) The disastrous gale is mainly located in the center and its surrounding areas of surface heavy rainfall and high density of ground lightning. Mesoscale characteristics associated with the ground gale, such as convergence line, convergence zone, cold pool and thunder high, are observed by AWS. Negative cloud-to-ground (CG) lightening dominated in the event, and the ratio of negative to positive CG is approximately 101:1. (3) The gust fronts, echo hanging, weak echo region (WER) and boundary weak echo region (BWER) are quite clear on the PPI and RHI charts of radar reflectiv-ity factors, and features such as mesosyclone, divergence on low tilts, large radial velocity region, inflow flows, divergence in the upper level and convergence in the low level are also evident in the radial velocity chart. The above characteristics are of significant importance in disas-trous gale detection and its early warning.