设为首页
加入收藏
Locations and Radiation Strength of Narrow Bipolar Pulses in a Thunderstorm
-
摘要: 双极性窄脉冲事件（NBE）是一类特殊的大气放电现象，能产生强甚低频/低频（VLF/LF）和甚高频（VHF）辐射。为了探索NBE发生的气象环境和放电特性，选出重庆双频段闪电定位网络在一次雷暴过程中观测到的608次正极性NBE（简称正NBE）和82次负极性NBE（简称负NBE），对比发生位置和辐射强度。结果表明：正NBE主要分布于7~15 km高度处，归一化到距离辐射源100 km处的VLF/LF电场变化峰值的平均值为13.4 V·m-1，平均VHF辐射功率为73.5 kW。负NBE主要发生在两个高度范围，72例负NBE分布于16~20 km高度，它们倾向于发生在30~35 dBZ回波顶高大于18 km的对流云顶及附近，其平均归一化VLF/LF电场变化峰值为42.7 V·m-1，平均VHF辐射功率为76.9 kW。10例负NBE分布于4~8 km高度，全部发生于对流核内部。其平均归一化的VLF/LF电场变化峰值为2.7 V·m-1，平均VHF辐射功率为18.2 kW。从统计结果看，在VLF/LF频段，上部负NBE的辐射强度普遍强于正NBE和下部负NBE；在VHF频段，上部负NBE的辐射强度与正NBE基本相当，大于下部负NBE；下部负NBE在两个频段的辐射通常弱于正NBE。Abstract: Narrow bipolar pulses (NBE) are special flashes in thunderstorms which are different from regular in-cloud discharges and cloud-to-ground discharges. They can produce intense radiation in both VLF/LF and VHF bands. To explore the meteorological environment and discharge characteristics of NBE, locations and radiation strength of 608 positive NBE and 82 negative NBE detected in a thunderstorm day are analyzed using the dual band 3D lightning locating system in Chongqing. Results show that positive NBE occur at the altitude of 7-15 km, with the average altitude of 10.0 km. According to the radar reflectivity of positive NBE, they can be divided into three groups. 49 positive NBE, which occur in the thunderstorm cores (reflectivity), are categorized as Group Ⅰ. 350 NBE occurring in regions outside cores with the reflectivity higher than 5 dBZ are categorized as Group Ⅱ. The rest 209 positive NBE are Group Ⅲ. The radiation strength of these three groups are in descending order on both bands. The mean value of all positive NBE VLF/LF electric field change peaks normalized to 100 km is 13.4 V·m-1. The mean value of their VHF radiant powers is 73.5 kW. Negative NBE are generally produced in two regions in the thunderstorm. Among 82 negative NBE, 72 of them occur at the altitude of 16-20 km, and the average altitude is 18.0 km. They occur on or beside tops of thunderstorms with 30-35 dBZ echo heights higher than 18 km. The mean value of their VLF/LF electric field change peaks normalized to 100 km is 42.7 V·m-1. The mean value of the VHF radiant powers is 76.9 kW. 10 negative NBE occur at the altitude of 4-10 km, whose average altitude is 6.0 km. They all occur in thunderstorm cores. The mean value of VLF/LF electric field change peaks normalized to 100 km is 2.7 V·m-1. The mean value of VHF radiant powers is 18.2 kW. According to statistical results, the radiation strength of the upper negative NBE is mostly stronger than those of positive NBE and the lower negative NBE on VLF/LF band. In VHF band, values are similar, both of which are stronger than the lower negative NBE. The radiation strength of the lower negative NBE is weaker than that of positive NBE in both bands.
-
Key words:
- narrow bipolar pulses;
- altitude;
- location;
- radiation strength
-
图 1 站网布局及垂直定位误差的蒙特卡洛模拟结果(a)时间测量误为200 ns、高度为12 km时垂直定位误差的蒙特卡洛模拟与NBE定位点叠加图，(b)时间测量误为50 ns、高度为12 km时垂直定位误差的蒙特卡洛模拟
(黑色线代表行政区边界；黑色菱形代表观测站，蓝色点代表正NBE，红色点代表负NBE；填色代表误差的分布)
Fig. 1 Layout of the network and the vertical estimated errors given by Monte Varlo simulation (a)the vertical estimated errors given by Monte Varlo simulation at altitude of 12 km when the timing error is 200 ns with locations of NBE, (b)the vertical estimated errors given by Monte Varlo simulation at altitude of 12 km when the timing error is 500 ns
(black lines represent the boundary of the administrative regions; black rhombuses represent the observation sites, blue dots represent positive NBE, red dots represent negative NBE, contoufs represent the distribution of errors)
图 2 NBE的VLF/LF电场波形和VHF功率波形图(a)北碚站探测到的1次正NBE的波形图，(b)铁山坪站探测到的1次负NBE的波形图
Fig. 2 VLF/LF electric waveforms and the received VHF radiant power waveforms of NBE (a)waveforms of a positive NBE detected by Beibei Site, (b)waveforms of a negative NBE detected by Tieshanping Site
图 3 VHF接收机在260 MHz的测试频率下的标定结果
Fig. 3 The calibration of VHF receivers in the test frequency of 260 MHz
图 5 雷达反射率因子垂直剖面与6 min内NBE定位点的叠加图(a)第1类正NBE，(b)发生在上部对流区域外侧、未发生在对流核正上方的第2类正NBE，(c)发生上部对流区域外侧、对流核正上方的第2类正NBE，(d)发生在对流核斜上方的对流云顶的第1类负NBE，(e)发生在对流核正上方的对流云顶的第1类负NBE，(f)第2类负NBE
(蓝色星形代表正NBE，红色星形代表负NBE，填色代表雷达反射率因子)
Fig. 5 Vertical sections of radar echoes with locations of NBE within 6 min (a)the first group of positive NBE, (b)the second group of positive NBE occurring outside the upper convection region on the inclined top of convective core, (c)the second group of positive NBE occurring outside the upper convection region on the top of convective core, (d)the first group of negative NBE occurring on the inclined top of convective core, (e)the first group of negative NBE occurring on the top of convective core, (f)the second group of negative NBE
(blue stars represent positive NBE, red stars represent negative NBE, shaded areas present radar reflectivities)
图 6 正、负NBE的辐射强度和高度分布(a)正、负NBE的VLF/LF电场变化峰值和高度分布，(b)正、负NBE的VHF辐射功率和高度分布
Fig. 6 Altitudes of positive and negative NBE versus their radiation strength (a)altitudes of positive and negative NBE versus their VLF/LF electric field change peaks, (b)altitudes of positive and negative NBE versus their VHF radiant powers
表 1 NBE孤立性特征
Table 1 Isolation characteristics of NBE
孤立性特征 正NBE 负NBE 第1类 第2类 第3类 第1类 第2类 起始云闪 6 40 44 0 3 起始地闪 1 3 6 0 2 孤立发生 42 307 169 72 5 
下载: 导出CSV
表 2 NBE辐射强度的计算结果
Table 2 Calculation results of NBE radiation strength
辐射强度 统计量 正NBE 负NBE 第1类 第2类 第3类 第1类 第2类 VLF/LF电场变化峰值/(V·m-1) 最大值 39.5 35.8 34.6 59.4 7.6 最小值 3.5 1.5 1.5 1.9 1.5 平均值 15.4 13.8 12.3 42.7 2.7 VHF辐射功率/kW 最大值 261.4 250.7 232.0 219.9 60.3 最小值 7.8 1.7 1.3 1.3 1.0 平均值 83.7 81.8 57.6 76.9 18.2
下载: 导出CSV
-
[1] Le Vine D M.Sources of the strongest RF radiation from lightning.Journal of Geophysical Research:Oceans, 1980, 85(C7):4091-4095. doi: 10.1029/JC085iC07p04091 [2] Willett J C, Bailey J C, Krider E P.A class of unusual lightning electric field waveforms with very strong high-frequency radiation.Journal of Geophysical Research:Atmospheres, 1989, 94(D13):16255-16267. doi: 10.1029/JD094iD13p16255 [3] Nag A, Rakov V A, Tsalikis D, et al.On phenomenology of compact intracloud lightning discharges.Journal of Geophysical Research:Atmospheres, 2010, 115:D14115. doi: 10.1029/2009JD012957 [4] 祝宝友, 陶善昌, 谭涌波.伴随超强VHF辐射的闪电双极性窄脉冲初步观测.气象学报, 2007, 65(1):124-130. http://www.oalib.com/paper/5064763 [5] Holden D N, Munson C P, Devenport J C.Satellite observations of transionospheric pulse pairs.Geophys Res Lett, 1995, 22(8):889-892. doi: 10.1029/95GL00432 [6] Thomas R J, Krehbiel P R, Rison W, et al.Observations of VHF source powers radiated by lightning.Geophys Res Lett, 2001, 28(1):143-146. doi: 10.1029/2000GL011464 [7] Jacobson A R, Heavner M J.Comparison of narrow bipolar events with ordinary lightning as proxies for severe convection.Mon Wea Rev, 2005, 133:1144-1154. doi: 10.1175/MWR2915.1 [8] Smith D A, Shao X M, Holden D N, et al.A distinct class of isolated intracloud lightning discharges and their associated radio emissions.Journal of Geophysical Research:Atmospheres, 1999, 104(D4):4189-4212. doi: 10.1029/1998JD200045 [9] Rison W, Thomas R J, Krehbiel P R, et al.A GPS-based three-dimensional lightning mapping system:Initial observations in central New Mexico.Geophys Res Lett, 1999, 26(23):3573-3576. doi: 10.1029/1999GL010856 [10] Smith D A, Eack K B, Harlin J, et al.The Los Alamos Sferic Array:A research tool for lightning investigations.Journal of Geophysical Research:Atmospheres, 2002, 107(D13):5-14. http://adsabs.harvard.edu/abs/2002JGRD..107.4183S [11] Wu T, Yoshida S, Ushio T, et al.Lightning-initiator type of narrow bipolar events and their subsequent pulse trains.J Geophys Res, 2014, 119(12):7425-7438. doi: 10.1002/2014JD021842/abstract [12] Cooray V, Lundquist S.Characteristics of the radiation fields from lightning in Sri Lanka in the tropics.Journal of Geophysical Research:Atmospheres, 1985, 90(D4):6099-6109. doi: 10.1029/JD090iD04p06099 [13] Zhu B, Zhou H, Ma M, et al.Observations of narrow bipolar events in East China.Journal of Atmospheric and Solar-Terrestrial Physics, 2010, 72:271-278. doi: 10.1016/j.jastp.2009.12.002 [14] Wu T, Dong W, Zhang Y, et al.Comparison of positive and negative compact intracloud discharges.Journal of Geophysical Research:Atmospheres, 2011, 116:D3111. doi: 10.1029/2010JD015233 [15] Rison W, Krehbiel P R, Stock M G, et al.Observations of narrow bipolar events reveal how lightning is initiated in thunderstorms.Nat Commun, 2016, 7:10721. doi: 10.1038/ncomms10721 [16] 张广庶, 王彦辉, 郄秀书, 等.基于时差法三维定位系统对闪电放电过程的观测研究.中国科学(地球科学), 2010, 40(4):523-534. http://earth.scichina.com:8080/sciD/CN/abstract/abstract417082.shtml [17] Wang Y, Zhang G, Qie X, et al.Characteristics of compact intracloud discharges observed in a severe thunderstorm in northern part of China.Journal of Atmospheric and Solar-Terrestrial Physics, 2012, 84-85:7-14. doi: 10.1016/j.jastp.2012.05.003 [18] 张义军, 孟青, 马明, 等.闪电探测技术发展和资料应用.应用气象学报, 2006, 17(5):611-620. doi: 10.11898/1001-7313.20060504 [19] Wu T, Dong W, Zhang Y, et al.Discharge height of lightning narrow bipolar events.Journal of Geophysical Research:Atmospheres, 2012, 117:D5119. doi: 10.1029/2011JD017054/full [20] Lü F, Zhu B, Zhou H, et al.Observations of compact intracloud lightning discharges in the northernmost region (51°N) of China.Journal of Geophysical Research:Atmospheres, 2013, 118(10):4458-4465. doi: 10.1002/jgrd.50295 [21] Wiens K C, Hamlin T, Harlin J, et al.Relationships among Narrow Bipolar Events, "total" lightning, and radar-inferred convective strength in Great Plains thunderstorms.Journal of Geophysical Research:Atmospheres, 2008, 113:D5201. doi: 10.1029/2007JB005081 [22] Wu T, Takayanagi Y, Yoshida S, et al.Spatial relationship between lightning narrow bipolar events and parent thunderstorms as revealed by phased array radar.Geophys Res Lett, 2013, 40(3):618-623. doi: 10.1002/grl.50112 [23] 张义军, 徐良韬, 郑栋, 等.强风暴中反极性电荷结构研究进展.应用气象学报, 2014, 25(5):513-526. doi: 10.11898/1001-7313.20140501 [24] 张义军, 周秀骥.雷电研究的回顾和进展.应用气象学报, 2006, 17(6):829-834. doi: 10.11898/1001-7313.20060619 [25] Liu H, Dong W, Wu T, et al.Observation of compact intracloud discharges using VHF broadband interferometers.Journal of Geophysical Research:Atmospheres, 2012, 117:D1203. http://ieeexplore.ieee.org/abstract/document/6344211 [26] 刘恒毅, 董万胜, 张义军.云闪K过程的三维时空特征.应用气象学报, 2017, 28(6):700-713. doi: 10.11898/1001-7313.20170606 [27] 张志孝, 郑栋, 张义军, 等.闪电初始阶段和尺度判别方法及其特征.应用气象学报, 2017, 28(4):414-426. doi: 10.11898/1001-7313.20170403 [28] 刘恒毅, 董万胜, 徐良韬, 等.闪电起始过程时空特征的宽带干涉仪三维观测.应用气象学报, 2016, 27(1):16-24. doi: 10.11898/1001-7313.20160102 [29] 董万胜, 刘欣生, 张义军, 等.25~100 MHz频段闪电脉冲辐射能量频谱特征.中国电机工程学报, 2003, 23(3):104-107. https://www.wenkuxiazai.com/doc/f06226c7f90f76c661371aee-4.html [30] Betz H D, Marshall T C, Stolzenburg M, et al.Detection of in-cloud lightning with VLF/LF and VHF networks for studies of the initial discharge phase.Geophys Res Lett, 2008, 35:L23802. doi: 10.1029/2008GL035820 [31] Shao X, Stanley M, Regan A, et al.Total lightning observations with the new and improved Los Alamos Sferic Array (LASA).J Atmos Ocean Technol, 2006, 23(10):1273-1288. doi: 10.1175/JTECH1908.1 [32] Thomas R J, Krehbiel P R, Rison W, et al.Accuracy of the lightning mapping array.Journal of Geophysical Research:Atmospheres, 2004, 109:D14207. doi: 10.1029/2004JD004549 [33] 张文娟, 孟青, 吕伟涛, 等.时间差闪电监测网的误差分析和布局优化.应用气象学报, 2009, 20(4):402-410. doi: 10.11898/1001-7313.20090403 [34] 肖艳姣, 刘黎平.新一代天气雷达网资料的三维格点化及拼图方法研究.气象学报, 2006, 64(5):647-657. doi: 10.11676/qxxb2006.063 [35] 王飞, 张义军, 赵均壮, 等.雷达资料在孤立单体雷电预警中的初步应用.应用气象学报, 2008, 19(2):153-160. doi: 10.11898/1001-7313.20080228 [36] Uman M A, Mclain D K, Krider E P.The electromagnetic radiation from a finite antenna.American Journal of Physics, 1975, 43(1):33-38. doi: 10.1119/1.10027 [37] 武斌, 张广庶, 文军, 等.闪电初始预击穿过程辐射脉冲特征及电流模型.应用气象学报, 2017, 28(5):555-567. doi: 10.11898/1001-7313.20170504 [38] 刘妍秀, 张广庶, 王彦辉, 等.闪电VHF辐射源功率观测及雷暴电荷结构的初步分析.高原气象, 2016, 35(6):1662-1670. doi: 10.7522/j.issn.1000-0534.2016.00051 [39] Smith D A, Heavner M J, Jacobson A R, et al.A method for determining intracloud lightning and ionospheric heights from VLF/LF electric field records.Radio Science, 2004, 39:S1010. doi: 10.1029/2002RS002790/references [40] 吴亭, 董万胜, 李良福, 等.基于电离层反射的袖珍云闪(CID)三维定位研究.地球物理学报, 2012, 55(4):1095-1103. http://www.oalib.com/paper/4868794 [41] Robinson G D.The distribution of electricity in thunderclouds.Quarterly Journal of the Royal Meteorological Society, 1941, 67:332-340. doi: 10.1007%2FBF02247519.pdf [42] Stolzenburg M, Rust W D, Smull B F, et al.Electrical structure in thunderstorm convective regions1. Mesoscale convective systems.J Geophys Res, 1998, 103(D12):14059-14078. doi: 10.1029/97JD03546 [43] Karunarathna N, Marshall T C, Stolzenburg M, et al.Narrow bipolar pulse locations compared to thunderstorm radar echo structure.Journal of Geophysical Research:Atmospheres, 2015, 120(22):11690-11706. doi: 10.1002/2015JD023829 [44] Riousset J A, Pasko V P, Krehbiel P R, et al.Modeling of thundercloud screening charges:Implications for blue and gigantic jets.Journal of Geophysical Research:Space Physics, 2010, 115:A10E. doi: 10.1029/97JD03545 [45] 王飞, 董万胜, 张义军, 等.云内大粒子对闪电活动影响的个例模拟.应用气象学报, 2009, 20(5):564-570. doi: 10.11898/1001-7313.20090507 -
计量
- 摘要浏览量: 3394
- HTML全文浏览量: 1330
- PDF下载量: 250
- 被引次数: 0
