气象与环境科学
氣象與環境科學
기상여배경과학
METEOROLOGICAL AND ENVIRONMENTAL SCIENCES
2012年
4期
1-7
,共7页
张霞%王新敏%王金莲%齐伊玲
張霞%王新敏%王金蓮%齊伊玲
장하%왕신민%왕금련%제이령
暴雨%卫星云图%Tbb%湿位涡
暴雨%衛星雲圖%Tbb%濕位渦
폭우%위성운도%Tbb%습위와
rainstorm%satellite nephogram%Tbb%moist potential vorticity
2011年7月2-3日豫西北出现局地暴雨天气,降雨强度大、时段集中,具有明显的强对流暴雨持征,其中有2站达大暴雨。采用1°×1°NCEP再分析资料进行环流背景分析和物理量诊断,结果表明:这次暴雨是由高空低槽和中低空切变线直接影响所致,高湿不稳定区的稳定持续为雨区积累了大量不稳定能量,在冷空气入侵的激发下,不稳定能量释放产生强对流降水;低层气旋性环流的形成和气旋性弯曲的存在利于上升运动加强,水汽的输送和辐合作用配合强烈的上升运动使得强降水持续;高层干位涡向对流层低层扰动下传具有促使低层气旋性涡旋生成和加强的作用,位涡的传播特征与未来4-6h的雨势强弱对应较好。利用FY-2E卫星资料结合自动站逐小时降水量对暴雨中尺度特征进行分析,结果显示,这次暴雨过程中存在明显的中尺度云团自组织现象,强降水是组织、合并后的一个中α尺度对流云团内部两个中β尺度的强雨团直接造成的;Tbb〈221K的冷云覆盖区与暴雨落区相对应。
2011年7月2-3日豫西北齣現跼地暴雨天氣,降雨彊度大、時段集中,具有明顯的彊對流暴雨持徵,其中有2站達大暴雨。採用1°×1°NCEP再分析資料進行環流揹景分析和物理量診斷,結果錶明:這次暴雨是由高空低槽和中低空切變線直接影響所緻,高濕不穩定區的穩定持續為雨區積纍瞭大量不穩定能量,在冷空氣入侵的激髮下,不穩定能量釋放產生彊對流降水;低層氣鏇性環流的形成和氣鏇性彎麯的存在利于上升運動加彊,水汽的輸送和輻閤作用配閤彊烈的上升運動使得彊降水持續;高層榦位渦嚮對流層低層擾動下傳具有促使低層氣鏇性渦鏇生成和加彊的作用,位渦的傳播特徵與未來4-6h的雨勢彊弱對應較好。利用FY-2E衛星資料結閤自動站逐小時降水量對暴雨中呎度特徵進行分析,結果顯示,這次暴雨過程中存在明顯的中呎度雲糰自組織現象,彊降水是組織、閤併後的一箇中α呎度對流雲糰內部兩箇中β呎度的彊雨糰直接造成的;Tbb〈221K的冷雲覆蓋區與暴雨落區相對應。
2011년7월2-3일예서북출현국지폭우천기,강우강도대、시단집중,구유명현적강대류폭우지정,기중유2참체대폭우。채용1°×1°NCEP재분석자료진행배류배경분석화물리량진단,결과표명:저차폭우시유고공저조화중저공절변선직접영향소치,고습불은정구적은정지속위우구적루료대량불은정능량,재랭공기입침적격발하,불은정능량석방산생강대류강수;저층기선성배류적형성화기선성만곡적존재리우상승운동가강,수기적수송화복합작용배합강렬적상승운동사득강강수지속;고층간위와향대류층저층우동하전구유촉사저층기선성와선생성화가강적작용,위와적전파특정여미래4-6h적우세강약대응교호。이용FY-2E위성자료결합자동참축소시강수량대폭우중척도특정진행분석,결과현시,저차폭우과정중존재명현적중척도운단자조직현상,강강수시조직、합병후적일개중α척도대류운단내부량개중β척도적강우단직접조성적;Tbb〈221K적랭운복개구여폭우락구상대응。
A heavy rain process occurred in northwest Henan on July 2-3, 2011. There was two stations' 24 h rainfall achieved heavy rain, and the rainfall intensity was large and period was concentrat-ed, which presented obviously severe convection rainstorm characters. The circulation background analy-sis and physical diagnosis were studied to adopt NCEP 1°×1° reanalysis data. The result shows that : the middle and low-altitude low trough and shear line directly bring on the storm. Humidity unstable region continuously stabled has accumulated a large amount of unstable energy for the rain ; excited by the inva-sion of cold air, unstable energy release generates strong convective precipitation. The formation of cy-clonic circulation and the existence of cyclonic curvature in low-level are conducive to strengthen the up-ward motion; the water vapor transport and convergence as well as the strong upward motion cause the heavy precipitation continued. Dry potential vorticity in high-level propagating downstream perturbation to the lower troposphere prompts to cyclonic vortex formation and intensification. The propagation character-istics of potential vorticity match corresponding rain intensity in 4-6 h. Combined with the automatic sta-tion hourly precipitation, local heavy rain was analyzed by using FY-2E satellite data. The result shows: The rainstorm exists obviously cloud self-organization phenomena. The heavy precipitation is di-rectly occurred by two β-seale strong rain cloud, which is internal in one α-scale convective cloud after organization and combination. Cold cloud covered region (Tbb 〈 221 K) is corresponding to the heavy rainfall area.