北京一次大雹天气过程的闪电活动特征分析
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摘要
由于受闪电监测系统限制,已有研究多局限于强对流天气的地闪(cloud-to-ground lightning,CG)活动特征。本文利用VLF/LF三维闪电监测定位资料,结合雷达观测等资料对北京地区一次典型大雹天气过程的全闪活动特征进行了分析。结果表明:降雹发生前,闪电活动主要分布在对流系统的后部,闪电数较少,且以负地闪活动为主;降雹期间,闪电频数显著增加,云闪(intracloud lightning,IC)及正地闪活动明显加强,该阶段闪电活动主要集中在对流系统强回波中心及其前部雷达反射率因子梯度较大的区域;降雹结束之后,强回波中心基本移出北京,北京范围内的闪电频数明显减少。正闪比例在降雹发生前逐渐增大,在降雹期间稳定维持在较大值,降雹结束后迅速减小;云闪比(云闪频数/总闪频数)表现为降雹发生前和降雹结束后逐渐增大趋势,在降雹期间基本维持稳定少变。闪电的电流强度主要集中在5—50 kA之间,20 kA以下的低雷电流强度的云闪和地闪多发生在降雹期间及降雹结束后,而20 kA以上的高雷电流强度的云闪和地闪在降雹发生前占有很大比例,小于5kA的云闪在大雹发生期间所占比例明显高于地闪。降雹发生前及降雹结束后云闪发生高度在2—6 km,降雹期间有所抬升,约为2—8 km。闪电频数峰值超前于降水峰值5—20 min。
Due to the limitations of the lightning monitoring system,the existing studies were mostly limited to the cloud-to-ground lightning(CG)activity characteristics in the severe convective weather.In this paper,the data from the VLF/LF three-dimensional lightning monitoring and positioning system and radar observation stations w ere used to analyze the full lightning activity characteristics during a typical large hail weather process in Beijing.The results show that before the hail,the lightning activity is mainly distributed in the rear of the convection system,and the number of lightning is small, and the negative lightning activity is dominant.During the hail period,the frequency of lightning flashes(FLF)increases significantly,and the intracloud lightning(IC)and positive CG activities are significantly enhanced.The lightning activities in this stage are mainly concentrated at the center of the strong echo area and the regions with a large gradient of the front radar reflectivity factor of the convection system.After the hail,the strong echo center moves out of Beijing,and the FLF in Beijing decreases significantly.The proportion of positive lightning increases gradually before the occurrence of hail remains stable at a large value during the period of hail,and decreases rapidly after the end of hail.The IC lightning ratio(the frequency of IC lightning/the frequency of total lightning)shows a gradually increasing trend before and after the hail,and basically remains stable and changes little during the hail.The lightning current strength is mainly concentrated in the5-50 kA.The IC and CG with current intensity below 20 kA mostly occur during and after the hail,and those above 20 kA are dominant before the hail.The proportion of IC with a current intensity of less than 5 kA is higher than that of CG during the hail.Before and after the hail.the IC occurs at an altitude of 2-6 km,and increases during the hail,to about 2-8 km.The peak of FLF is 5-20 min ahead of that of precipitation.
Due to the limitations of the lightning monitoring system,the existing studies were mostly limited to the cloud-to-ground lightning(CG)activity characteristics in the severe convective weather.In this paper,the data from the VLF/LF three-dimensional lightning monitoring and positioning system and radar observation stations w ere used to analyze the full lightning activity characteristics during a typical large hail weather process in Beijing.The results show that before the hail,the lightning activity is mainly distributed in the rear of the convection system,and the number of lightning is small, and the negative lightning activity is dominant.During the hail period,the frequency of lightning flashes(FLF)increases significantly,and the intracloud lightning(IC)and positive CG activities are significantly enhanced.The lightning activities in this stage are mainly concentrated at the center of the strong echo area and the regions with a large gradient of the front radar reflectivity factor of the convection system.After the hail,the strong echo center moves out of Beijing,and the FLF in Beijing decreases significantly.The proportion of positive lightning increases gradually before the occurrence of hail remains stable at a large value during the period of hail,and decreases rapidly after the end of hail.The IC lightning ratio(the frequency of IC lightning/the frequency of total lightning)shows a gradually increasing trend before and after the hail,and basically remains stable and changes little during the hail.The lightning current strength is mainly concentrated in the5-50 kA.The IC and CG with current intensity below 20 kA mostly occur during and after the hail,and those above 20 kA are dominant before the hail.The proportion of IC with a current intensity of less than 5 kA is higher than that of CG during the hail.Before and after the hail.the IC occurs at an altitude of 2-6 km,and increases during the hail,to about 2-8 km.The peak of FLF is 5-20 min ahead of that of precipitation.
引文
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[2]Mac Gorman D R,Burgess D W.Positive cloud-toground lightning in tomadic storms and hailstorms[J].M onthly Weather Review,1994,122(8):1671-1697.
[3]Ge Z M,Yan M H,Guo C M,et al.Analysis of cloudto-ground lightning characteristics in mesoscale storm in Beijing area[J].Journal of M eteorological Research,1992,6(4):491-500.
[4]Yan M H,Guo C M,Qie X S,et al.Observation and model analysis of positive cloud-to-ground ligtning in mesoscale convective System[J].Acta M eteorologica Sinica,1992,6(1):501-510.
[5]Qie X S,Yan M H,Guo C M,et al.Ligtning data and study of thunderstorm now casting[J].Acta M eteorologica Sinica,1993,7(2):244-256.
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[7]冯桂力,郄秀书,周筠珺.一次中尺度对流系统的闪电演变特征[J].高原气象,2006,25(2):220-228.
[8]张萍萍,龙利民,张宁,等.2009年6月6日鄂北冰雹天气过程分析[J].气象与环境学报,2012,27(2):10-15.
[9]朱浩,孙浩,王凯,等.安徽省云地闪密度与雷暴日数关系的研究[J].气象与环境学报,2018,34(1):61-68.
[10]Holle R L,Watson A I,López R E,et al.The life cycle of lightning and severe w eather in a 3-4 June 1985PRE-STORM mesoscale convective system[J].M onthly Weather Review,1994,122(8):1798-1808.
[11]薛秋芳,孟青,葛润生.北京地区闪电活动及其与强对流天气的关系[J].气象,1999,25(11):15-19.
[12]Parker M D,Rutledge S A,Johnson R H.Cloud-toground lightning in linear mesoscale convective systems[J].Monthly Weather Review,2001,129(5):1232-1242.
[13]苟阿宁,赵玉春,黄延刚,等.一次西南涡引发暴雨的地闪特征[J].气象与环境学报,2013,29(4):59-63.
[14]苟阿宁,王晓玲,钟敏,等.湖北省一次强雹暴闪电和雷达回波特征分析[J].气象与环境学报,2015,31(3):7-14.
[15]马启明,迟文学,陈瑶,等.VLF/LF三维闪电监测定位系统的研制及初步试验结果[A]//暴雨新型探测资料应用技术研讨会论文集[C],2011.
[16]张文龙,崔晓鹏,黄荣.复杂地形下北京雷暴新生地点变化的加密观测研究[J].大气科学,2014,38(5):825-837.
[17]刘希文,李得勤,韦惠红,等.2013年湖北地区两次雷暴大风过程环境及雷达回波特征[J].气象与环境学报,2018,34(1):1-10.
[18]杨国祥.中小尺度天气学[M].北京:气象出版社,1983.
[19]顾媛,魏鸣.南京一次雷雨的闪电特征与多尺度资料分析[J].气象科学,2013,33(2):146-152.
[20]冯桂力,郡秀书,袁铁,等.雹暴的闪电活动特征与降水结构研究[J].中国科学,2007,37(1):123-132.
[21]支树林,娄桂杰.江西冰雹天气期间的闪电活动特征[J].气象与减灾研究,2009,32(3):36-41.
[22]郑栋,张义军,孟青,等.一次雹暴的闪电特征和电荷结构演变研究[J].气象学报,2010,68(2):248-263.
[23]冯桂力,郄秀书,吴书君.山东地区冰雹云的闪电活动特征[J].大气科学,2008,32(2):289-299.
[24]Ushio T,Heckman S J,Christian H J,et al.Vertical development of lightning activity observed by the LDARsystem:lightning bubbles[J].Journal of Applied M eteorology,2010,42(2):165-174.
[25]陈渭民.雷电学原理[M].气象出版社,2003.
[26]Piepgrass M V,Krider E P,Moore C B.Lightning and surface rainfall during Florida thunderstorms[J].Journal of Geophysical Research:Oceans,1982,87(C13):11193-11201.
[27]Gungle B,Krider E P.Cloud-to-ground lightning and surface rainfall in w arm-season Florida thunderstorms[J].Journal of Geophysical Research,2006,111:D19203,doi:10.1029/2005JD006802.
[2]Mac Gorman D R,Burgess D W.Positive cloud-toground lightning in tomadic storms and hailstorms[J].M onthly Weather Review,1994,122(8):1671-1697.
[3]Ge Z M,Yan M H,Guo C M,et al.Analysis of cloudto-ground lightning characteristics in mesoscale storm in Beijing area[J].Journal of M eteorological Research,1992,6(4):491-500.
[4]Yan M H,Guo C M,Qie X S,et al.Observation and model analysis of positive cloud-to-ground ligtning in mesoscale convective System[J].Acta M eteorologica Sinica,1992,6(1):501-510.
[5]Qie X S,Yan M H,Guo C M,et al.Ligtning data and study of thunderstorm now casting[J].Acta M eteorologica Sinica,1993,7(2):244-256.
[6]Nielsen K E,Maddox R A,Vasiloff S V.The evolution of cloud-to-ground lightning w ithin a portion of the10-11 June 1985 squall line[J].M onthly Weather Review,1994,122(8):1809-1817.
[7]冯桂力,郄秀书,周筠珺.一次中尺度对流系统的闪电演变特征[J].高原气象,2006,25(2):220-228.
[8]张萍萍,龙利民,张宁,等.2009年6月6日鄂北冰雹天气过程分析[J].气象与环境学报,2012,27(2):10-15.
[9]朱浩,孙浩,王凯,等.安徽省云地闪密度与雷暴日数关系的研究[J].气象与环境学报,2018,34(1):61-68.
[10]Holle R L,Watson A I,López R E,et al.The life cycle of lightning and severe w eather in a 3-4 June 1985PRE-STORM mesoscale convective system[J].M onthly Weather Review,1994,122(8):1798-1808.
[11]薛秋芳,孟青,葛润生.北京地区闪电活动及其与强对流天气的关系[J].气象,1999,25(11):15-19.
[12]Parker M D,Rutledge S A,Johnson R H.Cloud-toground lightning in linear mesoscale convective systems[J].Monthly Weather Review,2001,129(5):1232-1242.
[13]苟阿宁,赵玉春,黄延刚,等.一次西南涡引发暴雨的地闪特征[J].气象与环境学报,2013,29(4):59-63.
[14]苟阿宁,王晓玲,钟敏,等.湖北省一次强雹暴闪电和雷达回波特征分析[J].气象与环境学报,2015,31(3):7-14.
[15]马启明,迟文学,陈瑶,等.VLF/LF三维闪电监测定位系统的研制及初步试验结果[A]//暴雨新型探测资料应用技术研讨会论文集[C],2011.
[16]张文龙,崔晓鹏,黄荣.复杂地形下北京雷暴新生地点变化的加密观测研究[J].大气科学,2014,38(5):825-837.
[17]刘希文,李得勤,韦惠红,等.2013年湖北地区两次雷暴大风过程环境及雷达回波特征[J].气象与环境学报,2018,34(1):1-10.
[18]杨国祥.中小尺度天气学[M].北京:气象出版社,1983.
[19]顾媛,魏鸣.南京一次雷雨的闪电特征与多尺度资料分析[J].气象科学,2013,33(2):146-152.
[20]冯桂力,郡秀书,袁铁,等.雹暴的闪电活动特征与降水结构研究[J].中国科学,2007,37(1):123-132.
[21]支树林,娄桂杰.江西冰雹天气期间的闪电活动特征[J].气象与减灾研究,2009,32(3):36-41.
[22]郑栋,张义军,孟青,等.一次雹暴的闪电特征和电荷结构演变研究[J].气象学报,2010,68(2):248-263.
[23]冯桂力,郄秀书,吴书君.山东地区冰雹云的闪电活动特征[J].大气科学,2008,32(2):289-299.
[24]Ushio T,Heckman S J,Christian H J,et al.Vertical development of lightning activity observed by the LDARsystem:lightning bubbles[J].Journal of Applied M eteorology,2010,42(2):165-174.
[25]陈渭民.雷电学原理[M].气象出版社,2003.
[26]Piepgrass M V,Krider E P,Moore C B.Lightning and surface rainfall during Florida thunderstorms[J].Journal of Geophysical Research:Oceans,1982,87(C13):11193-11201.
[27]Gungle B,Krider E P.Cloud-to-ground lightning and surface rainfall in w arm-season Florida thunderstorms[J].Journal of Geophysical Research,2006,111:D19203,doi:10.1029/2005JD006802.