应用气象学报
應用氣象學報
응용기상학보
QUARTERLY JOURNAL OF APPLIED METEOROLOGY
2013年
6期
741-752
,共12页
周泓%尤红%李璠%蔡爱萍
週泓%尤紅%李璠%蔡愛萍
주홍%우홍%리번%채애평
冷锋切变型暴雨%中尺度特征%广义湿位涡%诊断分析
冷鋒切變型暴雨%中呎度特徵%廣義濕位渦%診斷分析
랭봉절변형폭우%중척도특정%엄의습위와%진단분석
cold front and shear rainstorm%mesoscale features%generalized moist potential vorticity%diag-nostic analysis
利用地面加密观测资料、多普勒天气雷达回波强度、卫星云图TBB资料和NCEP 1°×1°分析资料,应用滤波和广义位涡理论,对2012年6月1-2日云南省中部的首场切变冷锋型暴雨天气过程进行诊断分析。结果表明:中尺度天气系统是该次暴雨产生的直接原因,强降水均发生在云顶亮温等值线梯度较大一侧,回波强度空间分布不均匀,回波发展高度较低,但回波结构致密,低质心,以液态降水粒子为主,因此降水分布不均匀,但降水效率高;水汽源地为孟加拉湾;低层水汽通量辐合带与冷锋、切变线、中尺度辐合线以及β中尺度低涡位置有较好的对应关系;700 hPa,850 hPa水汽通量强辐合区中心位置叠加时,其所在区域地面降水增强;强降水区域上空中低层广义湿位涡的正异常现象体现了降水区中低层高水汽集中特征;单站上空低层的广义湿位涡正异常增加时,地面降水强度增加,反之减小;800 hPa 广义湿位涡正异常区对地面降水分布有一定指示作用,但暴雨中心与广义湿位涡强中心并不完全重合。
利用地麵加密觀測資料、多普勒天氣雷達迴波彊度、衛星雲圖TBB資料和NCEP 1°×1°分析資料,應用濾波和廣義位渦理論,對2012年6月1-2日雲南省中部的首場切變冷鋒型暴雨天氣過程進行診斷分析。結果錶明:中呎度天氣繫統是該次暴雨產生的直接原因,彊降水均髮生在雲頂亮溫等值線梯度較大一側,迴波彊度空間分佈不均勻,迴波髮展高度較低,但迴波結構緻密,低質心,以液態降水粒子為主,因此降水分佈不均勻,但降水效率高;水汽源地為孟加拉灣;低層水汽通量輻閤帶與冷鋒、切變線、中呎度輻閤線以及β中呎度低渦位置有較好的對應關繫;700 hPa,850 hPa水汽通量彊輻閤區中心位置疊加時,其所在區域地麵降水增彊;彊降水區域上空中低層廣義濕位渦的正異常現象體現瞭降水區中低層高水汽集中特徵;單站上空低層的廣義濕位渦正異常增加時,地麵降水彊度增加,反之減小;800 hPa 廣義濕位渦正異常區對地麵降水分佈有一定指示作用,但暴雨中心與廣義濕位渦彊中心併不完全重閤。
이용지면가밀관측자료、다보륵천기뢰체회파강도、위성운도TBB자료화NCEP 1°×1°분석자료,응용려파화엄의위와이론,대2012년6월1-2일운남성중부적수장절변랭봉형폭우천기과정진행진단분석。결과표명:중척도천기계통시해차폭우산생적직접원인,강강수균발생재운정량온등치선제도교대일측,회파강도공간분포불균균,회파발전고도교저,단회파결구치밀,저질심,이액태강수입자위주,인차강수분포불균균,단강수효솔고;수기원지위맹가랍만;저층수기통량복합대여랭봉、절변선、중척도복합선이급β중척도저와위치유교호적대응관계;700 hPa,850 hPa수기통량강복합구중심위치첩가시,기소재구역지면강수증강;강강수구역상공중저층엄의습위와적정이상현상체현료강수구중저층고수기집중특정;단참상공저층적엄의습위와정이상증가시,지면강수강도증가,반지감소;800 hPa 엄의습위와정이상구대지면강수분포유일정지시작용,단폭우중심여엄의습위와강중심병불완전중합。
Based on intensive observations,hourly FY-2E infrared TBB data,Doppler radar echo data and analy-sis data of NCEP (1°×1°,4 times a day),the first rainstorm process in central Yunnan from 1 June to 2 June in 2012 are diagnostically analyzed using meso scale filtering method and generalized moist potential vortices theories (GMPV). <br> The result shows that this strong precipitation process is caused by cold front and sheer,which is typ-ical in central Yunnan.Shear line,mesoscale convergence line and meso-β-scale low vortex are significant at 700 hPa after mesoscale filtering,but they are not obvious in largescale original stream fields.So the di-rect causes for this rainstorm process are mesoscale weather systems.It seems apparent that the rainstorm always happens at the side which TBB gradient is higher in the convective cloud clusters by hourly FY-2E infrared TBB data.After analysis on Doppler radar echo data,there is a large area of flocculent echoes at the strong precipitation region,and then some convective clouds develop in these flocculent echoes.Distri-bution of rainfall is not uniform in space and the efficiency of rainfall is high because of uneven distribution of echoes in space,low height and dense structure of echoes.The source region of water vapor is the Bay of Bengal.The water vapor convergence zones have a good correlation with the position of surface cold front,shear line,mesoscale convergence line and meso-β-scale low vortex at 700 hPa.The ground precipi-tation strengthens when the center of vapor convergence area at 700 hPa and 850 hPa are superimposed. <br> The positive anomaly of GMPV at mid-low layers over strong rainfall area can reflect characteristics of high water vapor convergence.Vertical distribution and change of GPMV at the low layer of single station show good indicative significance in this strong rainfall process.The rainfall is intensified when the posi-tive anomaly of GPMV at the low layer of single station increase,and vice versa.The GMPV at 800 hPa has an indicative effect on the location of heavy rainfall.The area of GPMV positive anomaly is always lo-cated in the center of strong precipitation and its surrounding area,but the center of strong precipitation is not coincided with the center of positive anomaly of GMPV completely.The forecast of this process will be better if the circulation patterns are analyzed synthetically,and the generalized moist potential vorticity theories are used as well.