苏北一次强降水超级单体风暴过程的诊断分析
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摘要
利用常规观测资料、NCEP再分析资料、FY2C卫星和多普勒雷达资料,对2008年7月22日发生在苏北的一次强降水超级单体风暴过程进行诊断分析。天气分析显示,风暴发生于高湿、较低的抬升凝结高度、强对流不稳定(3 445 J/kg)和中到强的垂直风切变(0~6 km,18 m/s)环境,这种大气环境非常有利于强降水超级单体风暴的发生发展。雷达回波分析揭示,该超级单体的演化可归结为"孤立单体—经典强降水超级单体—减弱东移"三个阶段,持续时间超过2 h。强降水超级单体风暴成熟期,呈现出典型的倒"V"型缺口、中低层有界弱回波区和反射率因子大值区由低层向高层往低层入流一侧倾斜的特征,相应的雷达径向速度场显示在倒"V"型缺口附近的强降水区中存在一个成熟的中气旋。湿位涡的诊断结果表明:高层干冷空气侵入触发潜在对流不稳定能量释放,有利于对流运动的发展;中低层大气对流不稳定与条件对称不稳定共存,既有垂直对流,又有倾斜对流发生,同时边界层的偏东风入流向暴雨区提供充沛的水汽,对暴雨的发生发展起增幅作用。
The diagnostic analysis on a heavy precipitation supercell storm process in northern Jiangsu province on 22 July 2008 is implemented by using the conventional observation data,NCEP reanalysis data,FY2 C satellite products and CINRAD-SA Doppler radar data.Weather analysis shows that the synoptic environment is characterized by the high humidity,strong convective instability(convective available potential energy,3 445 J/kg),medium to strong vertical wind shear(0—6 km,18 m/s) and lowLCL(lifting condensation level),which directly result in the generation and development of the heavy precipitation supercell storm.The radar echo analysis shows that the evolution of the heavy precipitation supercell can be generalized into three stages: the isolated cell develops increasingly,evolves into a classic heavy precipitation supercell and then weakens eastward gradually,lasting more than 2 h.Doppler radar base reflectivity and storm-relative radial velocity observations on various elevation angles are used to investigate the radar echo features of the heavy precipitation supercell storm. The results showthat at its mature stage,the heavy precipitation supercell storm displays a low-middle-level bounded weak echo,the larger radar reflectivity factor sloping toward the low-level inflowfrom lowlevel to high level,and associated typical front inverted "V "notch echo with the inflowin middle and lower levels.Corresponding radar radial velocity images showthat a well-developed mesoscale cyclone is in company with the inverted "V "notch echo in front of the supercell storm,and coincident with the heavy precipitation area at the surrounding of the inverted"V"notch echo.Through diagnosing the moist potential vorticity on isentropic surface and the moist potential vorticity during the process,results suggest that the intrusion of the durative dry cold air in upper levels touches off the release of potential convective instability energy,which is in favor of the development of convective motion.The atmospheric convective instability and conditional symmetric instability coexist in middle and lowlevels,so there are vertical convection and slantwise convection during the heavy rainfall,meanwhile the easterly inflowadjacent to the boundary layer transports ample water vapor to the heavy rain area,which plays an important role on the generation and development of the heavy rainstorm.
The diagnostic analysis on a heavy precipitation supercell storm process in northern Jiangsu province on 22 July 2008 is implemented by using the conventional observation data,NCEP reanalysis data,FY2 C satellite products and CINRAD-SA Doppler radar data.Weather analysis shows that the synoptic environment is characterized by the high humidity,strong convective instability(convective available potential energy,3 445 J/kg),medium to strong vertical wind shear(0—6 km,18 m/s) and lowLCL(lifting condensation level),which directly result in the generation and development of the heavy precipitation supercell storm.The radar echo analysis shows that the evolution of the heavy precipitation supercell can be generalized into three stages: the isolated cell develops increasingly,evolves into a classic heavy precipitation supercell and then weakens eastward gradually,lasting more than 2 h.Doppler radar base reflectivity and storm-relative radial velocity observations on various elevation angles are used to investigate the radar echo features of the heavy precipitation supercell storm. The results showthat at its mature stage,the heavy precipitation supercell storm displays a low-middle-level bounded weak echo,the larger radar reflectivity factor sloping toward the low-level inflowfrom lowlevel to high level,and associated typical front inverted "V "notch echo with the inflowin middle and lower levels.Corresponding radar radial velocity images showthat a well-developed mesoscale cyclone is in company with the inverted "V "notch echo in front of the supercell storm,and coincident with the heavy precipitation area at the surrounding of the inverted"V"notch echo.Through diagnosing the moist potential vorticity on isentropic surface and the moist potential vorticity during the process,results suggest that the intrusion of the durative dry cold air in upper levels touches off the release of potential convective instability energy,which is in favor of the development of convective motion.The atmospheric convective instability and conditional symmetric instability coexist in middle and lowlevels,so there are vertical convection and slantwise convection during the heavy rainfall,meanwhile the easterly inflowadjacent to the boundary layer transports ample water vapor to the heavy rain area,which plays an important role on the generation and development of the heavy rainstorm.
引文
Browning K A,1964.Airflowand precipitation trajectories within severe local storms which travel to the right of the winds[J].J Atmos Sci,21(6):634-639.
Browning K A,Ludlam F H,1962.Airflowin convective storms[J].Quart J Roy Meteor Soc,88:117-135.
Browning K A,Donaldson R J,1963.Airflowand structure of a tornadic storm[J].J Atmos Sci,20:533-545.
Burgess D W,Brown R A,Lemon L R,et al.,1977.Evolution of a tornadic thunderstorm[C]//10th conf on severe local storms.Omaha,NE:Amer Meteor Soc:84-89.
丁一汇,2008.中国气象灾害大典:综合卷[M].北京:气象出版社:326-346.Ding Y H,2008.Meteorological disaster Chinese ceremony:comprehensive volume[M].Beijing:China Meteorological Press:326-346.(in Chinese).
Doswell C A,2001.Severe convective storms[J].Meteor Monogr,69:1-26.
Doswell C A,Burgess D W,1993.Tornadoes and tornadic storms:a reviewof conceptual models[J].Geophys Monogr,79:161-172.
French A J,Parker MD,2012.Observations of mergers between squall lines and isolated supercell thunderstorms[J].Wea Forecasting,27:255-278.
Fujita T T,1963.Analytical mesometeorology:a review,severe local storms[J].Meteor Monogr,5(27):77-125.
Lemon L R,Doswell C A,1979.Severe thunderstorm evolution and mesocyclone structure as related to tornadogenesis[J].Mon Wea Rev,107:1184-1197.
Moller A R,Doswell C A,Przybylinski R,1990.High-precipitation supercells:a conceptual model and documentation[C]//16th Conf on Severe Local Storms.Kananaskis Park,Alberta,Canada:Amer Meteor Soc:52-57.
Moller A R,Doswell C A,Foster MP,et al.,1994.The operational recognition of supercell thunderstorm environments and storm structures[J].Wea Forecasting,9:327-347.
慕建利,谌云,李泽椿,2014.一次陕西关中强暴雨环境条件及中尺度系统分析[J].大气科学学报,37(5):591-604.Mu J L,Shen Y,Li Z C,2014.The environmental conditions and mesoscale system of a heavy rainfall over the central Shaanxi Plain on 8-9 August 2007[J].Trans Atmos Sci,37(5):591-604.(in Chinese).
潘玉洁,赵坤,潘益农,2008.一次强飑线内强降水超级单体风暴的单多普勒雷达分析[J].气象学报,66(4):621-636.Pan Y J,Zhao K,Pan YN,2008.Single-Doppler radar observation of a heavy precipitation supercell on a severe squall line[J].Acta Meteor Sinica,66(4):621-636.(in Chinese).
Rotunno R,Klemp J B,1982.The influence of the shear-induced pressure gradient on thunderstorm motion[J].Mon Wea Rev,110:136-151.
寿绍文,励申申,寿亦萱,等,2012.中尺度大气动力学[M].北京:高等教育出版社:277-279.Shou S W,Li S S,Shou Y X,et al.,2012.Mesoscale atmospheric dynamics[M].Beijing:Higher Education Press:277-279.(in Chinese).
王啸华,曹舒娅,王金鑫,等,2012.一次秋季强降水超级单体风暴过程分析[J].气象科学,32(6):685-693.Wang X H,Cao S Y,Wang J X,et al.,2012.Mesoscale analysis on a severe supercell in autumn[J].Scientia Meteor Sinica,32(6):685-693.(in Chinese).
王秀明,钟青,韩慎友,2009.一次冰雹天气强对流(雹)云演变及超级单体结构的个例模拟研究[J].高原气象,28(2):352-365.Wang X M,Zhong Q,Han S Y,2009.A numerical case study on the evolution of hail cloud and the three-dimensional structure of supercell[J].Plateau Meteor,28(2):352-365.(in Chinese).
吴芳芳,俞小鼎,王慧,等,2010.一次强降水超级单体风暴多普勒天气雷达特征[J].大气科学学报,33(3):285-298.Wu F F,Yu X D,Wang H,et al.,2010.A HP supercell case study with the data of Doppler weather radar detection[J].Trans Atmos Sci,33(3):285-298.(in Chinese).
吴翠红,韦惠红,牛奔,2012.湖北东部雷暴大风雷达回波特征分析[J].大气科学学报,35(1):64-72.Wu C H,Wei H H,Niu B,2012.Radar echo characteristics analysis for thunderstorm gale in eastern Hubei Province[J].Trans Atmos Sci,35(1):64-72.(in Chinese).
杨成芳,朱君鉴,2008.一次弓状回波和超级单体过程分析[J].气象科学,28(4):409-414.Yang C F,Zhu J J,2008.Analysis on a bowecho and supercell process[J].Scientia Meteor Sinica,28(4):409-414.(in Chinese).
俞小鼎,郑媛媛,廖玉芳,等,2008.一次伴随强烈龙卷的强降水超级单体风暴研究[J].大气科学,32(3):508-522.Yu X D,Zheng Y Y,Liao YF,et al.,2008.Observational investigation of a tornadic heavy precipitation supercell storm[J].Chin J Atmos Sci,32(3):508-522.(in Chinese).
郑媛媛,俞小鼎,方翀,等,2004.一次典型超级单体风暴的多普勒天气雷达观测分析[J].气象学报,62(3):317-328.Zheng Y Y,Yu X D,Fang C,et al.,2004.Analysisof a strong classic supercell storm with Doppler weather radar data[J].Acta Meteor Sinica,62(3):317-328.(in Chinese).
Browning K A,Ludlam F H,1962.Airflowin convective storms[J].Quart J Roy Meteor Soc,88:117-135.
Browning K A,Donaldson R J,1963.Airflowand structure of a tornadic storm[J].J Atmos Sci,20:533-545.
Burgess D W,Brown R A,Lemon L R,et al.,1977.Evolution of a tornadic thunderstorm[C]//10th conf on severe local storms.Omaha,NE:Amer Meteor Soc:84-89.
丁一汇,2008.中国气象灾害大典:综合卷[M].北京:气象出版社:326-346.Ding Y H,2008.Meteorological disaster Chinese ceremony:comprehensive volume[M].Beijing:China Meteorological Press:326-346.(in Chinese).
Doswell C A,2001.Severe convective storms[J].Meteor Monogr,69:1-26.
Doswell C A,Burgess D W,1993.Tornadoes and tornadic storms:a reviewof conceptual models[J].Geophys Monogr,79:161-172.
French A J,Parker MD,2012.Observations of mergers between squall lines and isolated supercell thunderstorms[J].Wea Forecasting,27:255-278.
Fujita T T,1963.Analytical mesometeorology:a review,severe local storms[J].Meteor Monogr,5(27):77-125.
Lemon L R,Doswell C A,1979.Severe thunderstorm evolution and mesocyclone structure as related to tornadogenesis[J].Mon Wea Rev,107:1184-1197.
Moller A R,Doswell C A,Przybylinski R,1990.High-precipitation supercells:a conceptual model and documentation[C]//16th Conf on Severe Local Storms.Kananaskis Park,Alberta,Canada:Amer Meteor Soc:52-57.
Moller A R,Doswell C A,Foster MP,et al.,1994.The operational recognition of supercell thunderstorm environments and storm structures[J].Wea Forecasting,9:327-347.
慕建利,谌云,李泽椿,2014.一次陕西关中强暴雨环境条件及中尺度系统分析[J].大气科学学报,37(5):591-604.Mu J L,Shen Y,Li Z C,2014.The environmental conditions and mesoscale system of a heavy rainfall over the central Shaanxi Plain on 8-9 August 2007[J].Trans Atmos Sci,37(5):591-604.(in Chinese).
潘玉洁,赵坤,潘益农,2008.一次强飑线内强降水超级单体风暴的单多普勒雷达分析[J].气象学报,66(4):621-636.Pan Y J,Zhao K,Pan YN,2008.Single-Doppler radar observation of a heavy precipitation supercell on a severe squall line[J].Acta Meteor Sinica,66(4):621-636.(in Chinese).
Rotunno R,Klemp J B,1982.The influence of the shear-induced pressure gradient on thunderstorm motion[J].Mon Wea Rev,110:136-151.
寿绍文,励申申,寿亦萱,等,2012.中尺度大气动力学[M].北京:高等教育出版社:277-279.Shou S W,Li S S,Shou Y X,et al.,2012.Mesoscale atmospheric dynamics[M].Beijing:Higher Education Press:277-279.(in Chinese).
王啸华,曹舒娅,王金鑫,等,2012.一次秋季强降水超级单体风暴过程分析[J].气象科学,32(6):685-693.Wang X H,Cao S Y,Wang J X,et al.,2012.Mesoscale analysis on a severe supercell in autumn[J].Scientia Meteor Sinica,32(6):685-693.(in Chinese).
王秀明,钟青,韩慎友,2009.一次冰雹天气强对流(雹)云演变及超级单体结构的个例模拟研究[J].高原气象,28(2):352-365.Wang X M,Zhong Q,Han S Y,2009.A numerical case study on the evolution of hail cloud and the three-dimensional structure of supercell[J].Plateau Meteor,28(2):352-365.(in Chinese).
吴芳芳,俞小鼎,王慧,等,2010.一次强降水超级单体风暴多普勒天气雷达特征[J].大气科学学报,33(3):285-298.Wu F F,Yu X D,Wang H,et al.,2010.A HP supercell case study with the data of Doppler weather radar detection[J].Trans Atmos Sci,33(3):285-298.(in Chinese).
吴翠红,韦惠红,牛奔,2012.湖北东部雷暴大风雷达回波特征分析[J].大气科学学报,35(1):64-72.Wu C H,Wei H H,Niu B,2012.Radar echo characteristics analysis for thunderstorm gale in eastern Hubei Province[J].Trans Atmos Sci,35(1):64-72.(in Chinese).
杨成芳,朱君鉴,2008.一次弓状回波和超级单体过程分析[J].气象科学,28(4):409-414.Yang C F,Zhu J J,2008.Analysis on a bowecho and supercell process[J].Scientia Meteor Sinica,28(4):409-414.(in Chinese).
俞小鼎,郑媛媛,廖玉芳,等,2008.一次伴随强烈龙卷的强降水超级单体风暴研究[J].大气科学,32(3):508-522.Yu X D,Zheng Y Y,Liao YF,et al.,2008.Observational investigation of a tornadic heavy precipitation supercell storm[J].Chin J Atmos Sci,32(3):508-522.(in Chinese).
郑媛媛,俞小鼎,方翀,等,2004.一次典型超级单体风暴的多普勒天气雷达观测分析[J].气象学报,62(3):317-328.Zheng Y Y,Yu X D,Fang C,et al.,2004.Analysisof a strong classic supercell storm with Doppler weather radar data[J].Acta Meteor Sinica,62(3):317-328.(in Chinese).