2016年北京地区一次雷暴大风的观测研究
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摘要
利用常规气象观测资料、风廓线资料、北京观象台多普勒天气雷达产品、多普勒雷达变分同化分析系统(VDRAS)的反演资料和地面自动气象站客观分析资料,对2016年7月27日北京地区出现的一次雷暴大风天气的环境条件特征、风暴结构特征及演变机制进行了分析。结果显示:本次雷暴大风天气过程出现在弱天气尺度强迫环境中,较好的热力不稳定增强机制促使线状对流发展为弓形回波,形成雷暴大风天气。探空曲线中低层接近于干绝热的环境温度直减率和下沉对流有效位能突增等现象,对预报大风天气有较好的指示意义。上游雷暴的冷池出流与山前偏南暖湿气流在北京西部形成了明显的风向辐合,在强烈的扰动温度梯度和地形抬升的共同作用下,位于地面辐合抬升最强处触发新生单体并迅速发展。新生单体与风暴主体合并下山过程中,由于地形作用抬升了冷池出流高度,与平原地区偏南暖湿气流形成显著的不稳定层结,产生显著的扰动温度梯度,触发不稳定能量使雷暴在下山过程中强度增强。多普勒雷达产品上也表现为强的反射率因子核,并出现回波悬垂和有界弱回波区等特征,速度产品上可看到一对明显的端点涡旋。在冷池不断加强和端点涡旋对后入气流不断加速的共同作用下,后侧入流气流加强成为后侧入流急流,在低仰角速度产品上表现为显著的大风区。后侧入流气流将环境中的干冷空气夹卷进入云体,通过蒸发作用产生负浮力,使冷空气加速下沉,加之降水粒子的拖曳作用,最终造成剧烈的地面大风。
To investigate the environmental characteristics, storm structures and formation mechanism of the thunderstorm that occurred on 27 July 2016 in Beijing Area, the data of conventional observation, wind profile, Doppler weather radar, Variational Doppler Radar Analysis System(VDRAS) and automatic weather station(AWS) data are analyzed. The case analysis shows that this windstorm developed under a weak synoptic forcing background. The unstable thermodynamic condition enhanced the development of linear convection into bow echo, resulting in thunderstorm. The characteristic in sounding data such as the temperature laps rate in the lower troposphere was almost equal to the dry-adiabatanda sudden increase of DCAPE, which are indicative of windstorm weather. The cold pool outflow and warm-moist southerly flow at front of the mountain formed a convergence zone in the western region of Beijing. Under the combined action of significant disturbance temperature gradient and topographic forcing new thunderstorms were triggered. Because of the uplift of mountain area, the lifting of thunderstorm cold pool outflow caused significant disturbance temperature gradient, contributing to the development of the thermal instability, and triggered unstable energy, enhancing thunderstorm intensity in the process of coming down the hill. The Doppler radar product also showed a strong reflectivity core,an overhanging echo, boundary weak echo range and a book-end vortex in radial velocity images. Under the combined action of the intensive cold pool and the book-end vortex, the rear inflow was intensified, becoming rear-inflow jet, which was characterized by a strong wind zone in the low-elevation radial velocity images. The dry and cold air were trapped into the cloud by the rear-inflow, creating a negative buoyancy through evaporation. Combined with the dragging of precipitation particles, eventually, strong surface winds were formed.
To investigate the environmental characteristics, storm structures and formation mechanism of the thunderstorm that occurred on 27 July 2016 in Beijing Area, the data of conventional observation, wind profile, Doppler weather radar, Variational Doppler Radar Analysis System(VDRAS) and automatic weather station(AWS) data are analyzed. The case analysis shows that this windstorm developed under a weak synoptic forcing background. The unstable thermodynamic condition enhanced the development of linear convection into bow echo, resulting in thunderstorm. The characteristic in sounding data such as the temperature laps rate in the lower troposphere was almost equal to the dry-adiabatanda sudden increase of DCAPE, which are indicative of windstorm weather. The cold pool outflow and warm-moist southerly flow at front of the mountain formed a convergence zone in the western region of Beijing. Under the combined action of significant disturbance temperature gradient and topographic forcing new thunderstorms were triggered. Because of the uplift of mountain area, the lifting of thunderstorm cold pool outflow caused significant disturbance temperature gradient, contributing to the development of the thermal instability, and triggered unstable energy, enhancing thunderstorm intensity in the process of coming down the hill. The Doppler radar product also showed a strong reflectivity core,an overhanging echo, boundary weak echo range and a book-end vortex in radial velocity images. Under the combined action of the intensive cold pool and the book-end vortex, the rear inflow was intensified, becoming rear-inflow jet, which was characterized by a strong wind zone in the low-elevation radial velocity images. The dry and cold air were trapped into the cloud by the rear-inflow, creating a negative buoyancy through evaporation. Combined with the dragging of precipitation particles, eventually, strong surface winds were formed.
引文
陈明轩,王迎春,高峰,等,2011.基于雷达资料4DVar的低层热动力反演系统及其在北京奥运期间的初步应用分析[J].气象学报,69(1):64-78.
陈明轩,王迎春,肖现,等,2012.基于雷达资料四维变分同化和三维云模式对一次超级单体风暴发展维持热动力机制的模拟分析[J].大气科学,36(5):929-944.
陈双,王迎春,张文龙,等,2011.复杂地形下雷暴增强过程的个例研究[J].气象,37(7):802-813.
陈涛,代刊,张芳华,2013.一次华北飑线天气过程中环境条件与对流发展机制研究[J].气象,39(8):945-954.
丁一汇,2005.高等天气学:第2版[M].北京:气象出版社:318-321.
樊利强,王迎春,陈明轩,2009.利用雷达资料反演方法对北京地区一次强对流天气过程的分析[J].气象,35(11):9-16,161.
黄荣,王迎春,张文龙,2012.复杂地形下北京一次局地雷暴新生和增强机制初探[J].暴雨灾害,31(3)432-241.
康红,费建芳,黄小刚,等,2016.一次弱弓形飑线后方入流特征的观测分析[J].气象学报,74(2):176-188.
雷蕾,孙继松,魏东,2011.利用探空资料判别北京地区夏季强对流的天气类别[J].气象,37(2):136-141.
梁爱民,张庆红,申红喜,等,2006.北京地区雷暴大风预报研究[J].气象,32(11):73-80.
梁建宇,孙建华,2012. 2009年6月一次飑线过程灾害性大风的形成机制[J].大气科学,36(2):316-336.
廖晓农,2009.北京雷暴大风日环境特征分析[J].气候与环境研究,14(1):54-62.
廖晓农,于波,卢丽华,2009.北京雷暴大风气候特征及短时临近预报方法[J].气象,35(9):18-28.
刘凑华,曹勇,符娇兰,2013.基于变分法的客观分析算法及应用[J].气象学报,71(6):1172-1182.
秦丽,李耀东,高守亭,2006.北京地区雷暴大风的天气—气候学特征研究[J].气候与环境研究,11(6):754-762.
孙继松,2005.气流的垂直分布对地形雨落区的影响[J].高原气象,24(1):62-69.
孙继松,石增云,王令,2006.地形对夏季冰雹事件时空分布的影响研究[J].气候与环境研究,11(1):76-84.
孙继松,杨波,2008.地形与城市环流共同作用下的β中尺度暴雨[J].大气科学,32(6):1352-1364.
陶诗言,1980.中国之暴雨[M].北京:科学出版社:1-12.
王福侠,俞小鼎,裴宇杰,等,2016.河北省雷暴大风的雷达回波特征及预报关键点[J].应用气象学报,27(3):342-351.
王珏,张家国,王佑兵,等,2009.鄂东地区雷雨大风多普勒天气雷达回波特征[J].暴雨灾害,28(2):143-146.
吴庆梅,郭虎,杨波,等,2009.地形和城市热力环流对北京地区一次β中尺度暴雨的影响[J].气象,35(12):58-64.
肖现,陈明轩,高峰,等,2015.弱天气系统强迫下北京地区对流下山演变的热动力机制[J].大气科学,39(1):100-124.
肖现,王迎春,陈明轩,等,2013.基于雷达资料四维变分同化技术对北京地区一次下山突发性增强风暴热动力机制的模拟分析[J].气象学报,71(5):797-816.
许爱华,孙继松,许东蓓,等,2014.中国中东部强对流天气的天气形势分类和基本要素配置特征[J].气象,40(4):400-411.
俞小鼎,姚秀萍,熊廷南,等,2006.多普勒天气雷达原理与业务应用[M].北京:气象出版社:155-156.
俞小鼎,周小刚,王秀明,2012.雷暴与强对流临近天气预报技术进展[J].气象学报,70(3):311-337.
Chen Mingxuan,Wang Yingchun.Gao Feng,et al,2012. Diurnal variations in convective storm activity over contiguous North China during the warm season based on radar mosaic climatology[J]. J Geophys Res, 117(D20):D20115. DOI:10. 1029/2012JD018158.
Chen Mingxuan,Wang Yingchun.Gao Feng,et al,2014. Diurnal evolution and distribution of warm-season convective storms in different prevailing wind regimes over contiguous North China[J].J Geophys Res,119(6):2742-2763.
Fujita T T,Byers H R, 1977. Spearhead echo and downburst in the crash of an airliner[J]. Mon Wea Rev, 105(2):129-146.
Lin Pinfang,Chang Paoliang,Jou B J D,et al,2011. Warm season afternoon thunderstorm characteristics under weak synoptic-scale forcing over Taiwan Island[J]. Wea Forecasting,26(1):44-60.
Reap R M,MacGorman D R,1989. Cloud-to-ground lightning:climatological characteristics and relationships to model fields, radar observations, and severe local storms[J]. Mon Wea Rev, 117(3):518-535.
Rotunno R,Klemp J,Weisman M L,1988. A theory for strong, longlived squall lines[J]. J Atmos Sci,45(3):463-464.
Sun Juanzhen, Chen Mingxuan, Wang Yingchun, 2010. A frequentupdating analysis system based on radar,surface, and mesoscale model data for the Beijing 2008 forecast demonstration project[J]. Wea Forecasting,25(6):1715-1735.
Weisman M L,1992. The role of convectively generated rear-inflow jets in the evolution of long-lived mesoconvective systems[J]. J Atmos Sci,49(19):1826-1847.
Weisman M L, 1993. The genesis of severe, long-lived bow echoes[J]. J Atmos Sci, 50(4):645-670.
Weisman M L, Davis C A, 1998. Mechanisms for the generation of mesoscale vortices within quasi-linear convective systems[J]. J Atmos Sci,55(16):2603-2622.
Weisman M L,Klemp J B,Rotunno R,1988. Structure and evolution of numerically simulated squall lines[J]. J Atmos Sci, 45(14):1990-2013.
Wilson J W,Feng Yerong,Chen Min,et al,2010. Nowcasting challenges during the Beijing Olympics:successes, failures, and implications for future nowcasting systems[J]. Wea Forecasting,25(6):1691-1714.
陈明轩,王迎春,肖现,等,2012.基于雷达资料四维变分同化和三维云模式对一次超级单体风暴发展维持热动力机制的模拟分析[J].大气科学,36(5):929-944.
陈双,王迎春,张文龙,等,2011.复杂地形下雷暴增强过程的个例研究[J].气象,37(7):802-813.
陈涛,代刊,张芳华,2013.一次华北飑线天气过程中环境条件与对流发展机制研究[J].气象,39(8):945-954.
丁一汇,2005.高等天气学:第2版[M].北京:气象出版社:318-321.
樊利强,王迎春,陈明轩,2009.利用雷达资料反演方法对北京地区一次强对流天气过程的分析[J].气象,35(11):9-16,161.
黄荣,王迎春,张文龙,2012.复杂地形下北京一次局地雷暴新生和增强机制初探[J].暴雨灾害,31(3)432-241.
康红,费建芳,黄小刚,等,2016.一次弱弓形飑线后方入流特征的观测分析[J].气象学报,74(2):176-188.
雷蕾,孙继松,魏东,2011.利用探空资料判别北京地区夏季强对流的天气类别[J].气象,37(2):136-141.
梁爱民,张庆红,申红喜,等,2006.北京地区雷暴大风预报研究[J].气象,32(11):73-80.
梁建宇,孙建华,2012. 2009年6月一次飑线过程灾害性大风的形成机制[J].大气科学,36(2):316-336.
廖晓农,2009.北京雷暴大风日环境特征分析[J].气候与环境研究,14(1):54-62.
廖晓农,于波,卢丽华,2009.北京雷暴大风气候特征及短时临近预报方法[J].气象,35(9):18-28.
刘凑华,曹勇,符娇兰,2013.基于变分法的客观分析算法及应用[J].气象学报,71(6):1172-1182.
秦丽,李耀东,高守亭,2006.北京地区雷暴大风的天气—气候学特征研究[J].气候与环境研究,11(6):754-762.
孙继松,2005.气流的垂直分布对地形雨落区的影响[J].高原气象,24(1):62-69.
孙继松,石增云,王令,2006.地形对夏季冰雹事件时空分布的影响研究[J].气候与环境研究,11(1):76-84.
孙继松,杨波,2008.地形与城市环流共同作用下的β中尺度暴雨[J].大气科学,32(6):1352-1364.
陶诗言,1980.中国之暴雨[M].北京:科学出版社:1-12.
王福侠,俞小鼎,裴宇杰,等,2016.河北省雷暴大风的雷达回波特征及预报关键点[J].应用气象学报,27(3):342-351.
王珏,张家国,王佑兵,等,2009.鄂东地区雷雨大风多普勒天气雷达回波特征[J].暴雨灾害,28(2):143-146.
吴庆梅,郭虎,杨波,等,2009.地形和城市热力环流对北京地区一次β中尺度暴雨的影响[J].气象,35(12):58-64.
肖现,陈明轩,高峰,等,2015.弱天气系统强迫下北京地区对流下山演变的热动力机制[J].大气科学,39(1):100-124.
肖现,王迎春,陈明轩,等,2013.基于雷达资料四维变分同化技术对北京地区一次下山突发性增强风暴热动力机制的模拟分析[J].气象学报,71(5):797-816.
许爱华,孙继松,许东蓓,等,2014.中国中东部强对流天气的天气形势分类和基本要素配置特征[J].气象,40(4):400-411.
俞小鼎,姚秀萍,熊廷南,等,2006.多普勒天气雷达原理与业务应用[M].北京:气象出版社:155-156.
俞小鼎,周小刚,王秀明,2012.雷暴与强对流临近天气预报技术进展[J].气象学报,70(3):311-337.
Chen Mingxuan,Wang Yingchun.Gao Feng,et al,2012. Diurnal variations in convective storm activity over contiguous North China during the warm season based on radar mosaic climatology[J]. J Geophys Res, 117(D20):D20115. DOI:10. 1029/2012JD018158.
Chen Mingxuan,Wang Yingchun.Gao Feng,et al,2014. Diurnal evolution and distribution of warm-season convective storms in different prevailing wind regimes over contiguous North China[J].J Geophys Res,119(6):2742-2763.
Fujita T T,Byers H R, 1977. Spearhead echo and downburst in the crash of an airliner[J]. Mon Wea Rev, 105(2):129-146.
Lin Pinfang,Chang Paoliang,Jou B J D,et al,2011. Warm season afternoon thunderstorm characteristics under weak synoptic-scale forcing over Taiwan Island[J]. Wea Forecasting,26(1):44-60.
Reap R M,MacGorman D R,1989. Cloud-to-ground lightning:climatological characteristics and relationships to model fields, radar observations, and severe local storms[J]. Mon Wea Rev, 117(3):518-535.
Rotunno R,Klemp J,Weisman M L,1988. A theory for strong, longlived squall lines[J]. J Atmos Sci,45(3):463-464.
Sun Juanzhen, Chen Mingxuan, Wang Yingchun, 2010. A frequentupdating analysis system based on radar,surface, and mesoscale model data for the Beijing 2008 forecast demonstration project[J]. Wea Forecasting,25(6):1715-1735.
Weisman M L,1992. The role of convectively generated rear-inflow jets in the evolution of long-lived mesoconvective systems[J]. J Atmos Sci,49(19):1826-1847.
Weisman M L, 1993. The genesis of severe, long-lived bow echoes[J]. J Atmos Sci, 50(4):645-670.
Weisman M L, Davis C A, 1998. Mechanisms for the generation of mesoscale vortices within quasi-linear convective systems[J]. J Atmos Sci,55(16):2603-2622.
Weisman M L,Klemp J B,Rotunno R,1988. Structure and evolution of numerically simulated squall lines[J]. J Atmos Sci, 45(14):1990-2013.
Wilson J W,Feng Yerong,Chen Min,et al,2010. Nowcasting challenges during the Beijing Olympics:successes, failures, and implications for future nowcasting systems[J]. Wea Forecasting,25(6):1691-1714.