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Parkevich EV, Khirianova AI, Khirianov TF, Baidin IS, Shpakov KV, Tolbukhin DV, Rodionov AA, Bolotov YK, Ryabov VA, Ambrozevich SA, Oginov AV. Natural sources of intense ultra-high-frequency radiation in high-voltage atmospheric discharges. Phys Rev E 2023; 108:025201. [PMID: 37723730 DOI: 10.1103/physreve.108.025201] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/22/2023] [Accepted: 07/11/2023] [Indexed: 09/20/2023]
Abstract
We study the sources of intense ultra-high-frequency (UHF) radiation (in the frequency range 1-6 GHz) arising during the development of high-voltage atmospheric discharges. The discharges were initiated in a long discharge gap by applying an approximately 1-MV pulse with positive or negative polarity. By employing a radio registration system based on ultrawideband antennas, we managed to localize the UHF radiation sources in the discharge with centimeter accuracy and investigate their temporal and spatial correlation with the discharge structures. The vast majority of the localized sources turned out to be concentrated in the near-electrode regions. It is found that the generation mechanism of intense UHF radiation in a laboratory discharge cannot be unambiguously associated with such basic processes as the head-on collision of opposite-polarity streamers or the interaction of single streamers with the near-electrode plasma at the surface of metal electrodes. We discovered that the observed UHF emission appears basically as a precursor of the intense plasma development in a certain discharge region, whereinto a bright counterstreamer comes a bit later. The findings were confirmed by the statistical observations and results of imaging the dynamics of the discharge structures with a nanosecond temporal resolution.
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Affiliation(s)
- E V Parkevich
- P. N. Lebedev Physical Institute of the Russian Academy of Sciences, 53 Leninskiy Prospekt, Moscow 119991, Russia
| | - A I Khirianova
- P. N. Lebedev Physical Institute of the Russian Academy of Sciences, 53 Leninskiy Prospekt, Moscow 119991, Russia
| | - T F Khirianov
- P. N. Lebedev Physical Institute of the Russian Academy of Sciences, 53 Leninskiy Prospekt, Moscow 119991, Russia
| | - I S Baidin
- P. N. Lebedev Physical Institute of the Russian Academy of Sciences, 53 Leninskiy Prospekt, Moscow 119991, Russia
| | - K V Shpakov
- P. N. Lebedev Physical Institute of the Russian Academy of Sciences, 53 Leninskiy Prospekt, Moscow 119991, Russia
| | - D V Tolbukhin
- P. N. Lebedev Physical Institute of the Russian Academy of Sciences, 53 Leninskiy Prospekt, Moscow 119991, Russia
| | - A A Rodionov
- P. N. Lebedev Physical Institute of the Russian Academy of Sciences, 53 Leninskiy Prospekt, Moscow 119991, Russia
| | - Ya K Bolotov
- P. N. Lebedev Physical Institute of the Russian Academy of Sciences, 53 Leninskiy Prospekt, Moscow 119991, Russia
- Moscow Institute of Physics and Technology, Institutskiy Pereulok 9, Dolgoprudny, Moscow Region 141700, Russia
| | - V A Ryabov
- P. N. Lebedev Physical Institute of the Russian Academy of Sciences, 53 Leninskiy Prospekt, Moscow 119991, Russia
| | - S A Ambrozevich
- Bauman Moscow State Technical University, 5/1 2-ya Baumanskaya Street, Moscow 105005, Russia
| | - A V Oginov
- P. N. Lebedev Physical Institute of the Russian Academy of Sciences, 53 Leninskiy Prospekt, Moscow 119991, Russia
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A New Approach of 3D Lightning Location Based on Pearson Correlation Combined with Empirical Mode Decomposition. REMOTE SENSING 2021. [DOI: 10.3390/rs13193883] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/01/2023]
Abstract
To improve the accuracy of pulse matching and the mapping quality of lightning discharges, the Pearson correlation method combined with empirical mode decomposition (EMD) is introduced for discharge electric field pulse matching. This paper uses the new method to locate the lightning channels of an intra-cloud (IC) lightning flash and a cloud-to-ground (CG) lightning flash and analyzes the location results for the two lightning flashes. The results show that this method has a good performance in lightning location. Compared with the pulse-peak feature matching method, the positioning results of the new method are significantly improved, which is mainly due to the much larger number of positioning points (matched pulses). The number of located radiation sources has increased by nearly a factor of seven, which can significantly improve the continuity of the lightning channel and clearly distinguish the developmental characteristics. In the CG flash, there were three negative recoil streamers in the positive leader channel. After the three negative recoil streamers were finished, taking approximately 1 ms, 12 ms, and 2 ms, respectively, the negative leader channel underwent a K-process. The three negative recoil streamers are not connected to the K-processes in the negative leader channel. We think that the three negative recoil streamers may have triggered the three K-processes, respectively.
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3
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Hare BM, Scholten O, Dwyer J, Ebert U, Nijdam S, Bonardi A, Buitink S, Corstanje A, Falcke H, Huege T, Hörandel JR, Krampah GK, Mitra P, Mulrey K, Neijzen B, Nelles A, Pandya H, Rachen JP, Rossetto L, Trinh TNG, Ter Veen S, Winchen T. Radio Emission Reveals Inner Meter-Scale Structure of Negative Lightning Leader Steps. PHYSICAL REVIEW LETTERS 2020; 124:105101. [PMID: 32216418 DOI: 10.1103/physrevlett.124.105101] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/27/2019] [Revised: 11/29/2019] [Accepted: 02/06/2020] [Indexed: 06/10/2023]
Abstract
We use the Low Frequency Array (LOFAR) to probe the dynamics of the stepping process of negatively charged plasma channels (negative leaders) in a lightning discharge. We observe that at each step of a leader, multiple pulses of vhf (30-80 MHz) radiation are emitted in short-duration bursts (<10 μs). This is evidence for streamer formation during corona flashes that occur with each leader step, which has not been observed before in natural lightning and it could help explain x-ray emission from lightning leaders, as x rays from laboratory leaders tend to be associated with corona flashes. Surprisingly, we find that the stepping length is very similar to what was observed near the ground, however with a stepping time that is considerably larger, which as yet is not understood. These results will help to improve lightning propagation models, and eventually lightning protection models.
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Affiliation(s)
- B M Hare
- University of Groningen, KVI Center for Advanced Radiation Technology, 9747 AA Groningen, Netherlands
- University of Groningen, Kapteyn Astronomical Institute, Groningen 9700 AV, Netherlands
| | - O Scholten
- University of Groningen, KVI Center for Advanced Radiation Technology, 9747 AA Groningen, Netherlands
- University of Groningen, Kapteyn Astronomical Institute, Groningen 9700 AV, Netherlands
- Interuniversity Institute for High-Energy, Vrije Universiteit Brussel, Pleinlaan 2, 1050 Brussels, Belgium
| | - J Dwyer
- Department of Physics and Space Science Center (EOS), University of New Hampshire, Durham, New Hampshire 03824, USA
| | - U Ebert
- CWI, Centrum Wiskunde & Informatica, 1098 XG Amsterdam, Netherlands
- TU/e, Eindhoven University of Technology, 5612 AZ Eindhoven, Netherlands
| | - S Nijdam
- TU/e, Eindhoven University of Technology, 5612 AZ Eindhoven, Netherlands
| | - A Bonardi
- Department of Astrophysics/IMAPP, Radboud University Nijmegen, 6525 XZ Nijmegen, Netherlands
| | - S Buitink
- Department of Astrophysics/IMAPP, Radboud University Nijmegen, 6525 XZ Nijmegen, Netherlands
- Astrophysical Institute, Vrije Universiteit Brussel, Pleinlaan 2, 1050 Brussels, Belgium
| | - A Corstanje
- Department of Astrophysics/IMAPP, Radboud University Nijmegen, 6525 XZ Nijmegen, Netherlands
- Astrophysical Institute, Vrije Universiteit Brussel, Pleinlaan 2, 1050 Brussels, Belgium
| | - H Falcke
- Department of Astrophysics/IMAPP, Radboud University Nijmegen, 6525 XZ Nijmegen, Netherlands
- Nikhef, Science Park Amsterdam, 1098 XG Amsterdam, Netherlands
- Netherlands Institute for Radio Astronomy (ASTRON), 7991 PD Dwingeloo, Netherlands
- Max-Planck-Institut für Radioastronomie, 53121 Bonn, Germany
| | - T Huege
- Astrophysical Institute, Vrije Universiteit Brussel, Pleinlaan 2, 1050 Brussels, Belgium
- Institut für Kernphysik, Karlsruhe Institute of Technology(KIT), P.O. Box 3640, 76021, Karlsruhe, Germany
| | - J R Hörandel
- Department of Astrophysics/IMAPP, Radboud University Nijmegen, 6525 XZ Nijmegen, Netherlands
- Astrophysical Institute, Vrije Universiteit Brussel, Pleinlaan 2, 1050 Brussels, Belgium
- Nikhef, Science Park Amsterdam, 1098 XG Amsterdam, Netherlands
| | - G K Krampah
- Astrophysical Institute, Vrije Universiteit Brussel, Pleinlaan 2, 1050 Brussels, Belgium
| | - P Mitra
- Astrophysical Institute, Vrije Universiteit Brussel, Pleinlaan 2, 1050 Brussels, Belgium
| | - K Mulrey
- Astrophysical Institute, Vrije Universiteit Brussel, Pleinlaan 2, 1050 Brussels, Belgium
| | - B Neijzen
- University of Groningen, KVI Center for Advanced Radiation Technology, 9747 AA Groningen, Netherlands
| | - A Nelles
- Erlangen Center for Astroparticle Physics, Friedrich-Alexander-Univeristät Erlangen-Nürnberg, 91058, Erlangen, Germany
- DESY, Platanenallee 6, 15738, Zeuthen, Germany
| | - H Pandya
- Astrophysical Institute, Vrije Universiteit Brussel, Pleinlaan 2, 1050 Brussels, Belgium
| | - J P Rachen
- Astrophysical Institute, Vrije Universiteit Brussel, Pleinlaan 2, 1050 Brussels, Belgium
| | - L Rossetto
- Department of Astrophysics/IMAPP, Radboud University Nijmegen, 6525 XZ Nijmegen, Netherlands
| | - T N G Trinh
- Department of Physics, School of Education, Can Tho University Campus II, 3/2 Street, Ninh Kieu District, Can Tho City, Vietnam
| | - S Ter Veen
- Netherlands Institute for Radio Astronomy (ASTRON), 7991 PD Dwingeloo, Netherlands
| | - T Winchen
- Astrophysical Institute, Vrije Universiteit Brussel, Pleinlaan 2, 1050 Brussels, Belgium
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Peterson M, Rudlosky S, Zhang D. Changes to the Appearance of Optical Lightning Flashes Observed From Space According to Thunderstorm Organization and Structure. JOURNAL OF GEOPHYSICAL RESEARCH. ATMOSPHERES : JGR 2020; 125:10.1029/2019jd031087. [PMID: 32494551 PMCID: PMC7268918 DOI: 10.1029/2019jd031087] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/28/2019] [Accepted: 01/29/2020] [Indexed: 06/11/2023]
Abstract
Optical lightning observations from space reveal a wide range of flash structure. Lightning imagers such as the Geostationary Lightning Mapper and Lightning Imaging Sensor measure flash appearance by recording transient changes in cloud top illumination. The spatial and temporal optical energy distributions reported by these instruments depend on the physical structure of the flash and the distribution of hydrometeors within the thundercloud that scatter and absorb the optical emissions. This study explores how flash appearance changes according to the scale and organization of the parent thunderstorms with a focus on mesoscale convective systems. Clouds near the storm edge are frequently illuminated by large optical flashes that remain stationary between groups. These flashes appear large because their emissions can reflect off the exposed surfaces of nearby clouds to reach the satellite. Large stationary flashes also occur in small isolated thunderstorms. Optical flashes that propagate horizontally, meanwhile, are most frequently observed in electrified stratiform regions where extensive layered charge structures promote lateral development. Highly radiant "superbolts" occur in two scenarios: embedded within raining stratiform regions or in nonraining boundary/anvil clouds where optical emissions can take a relatively clear path to the satellite.
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Affiliation(s)
| | | | - Daile Zhang
- Earth System Science Interdisciplinary Center/Cooperative Institute for Climate and Satellites-Maryland, University of Maryland, College Park, MD, USA
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5
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Peterson M. Research Applications for the Geostationary Lightning Mapper Operational Lightning Flash Data Product. JOURNAL OF GEOPHYSICAL RESEARCH. ATMOSPHERES : JGR 2019; 124:10205-10231. [PMID: 31807399 PMCID: PMC6894167 DOI: 10.1029/2019jd031054] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/28/2019] [Accepted: 08/06/2019] [Indexed: 06/10/2023]
Abstract
The Lightning Cluster Filter Algorithm in the Geostationary Lightning Mapper (GLM) ground system identifies lightning flashes from the stream of event detections. It excels at clustering simple flashes but experiences anomalies with complex flashes that last longer than 3 s or contain more than 100 groups, leading to flashes being artificially split. We develop a technique that corrects these anomalies and apply it to the 2018 GLM data to document all lightning across the Americas. We produce statistics describing the characteristics and frequencies of reclustered GLM flashes and thunderstorm area features. The average GLM Americas flash rate in 2018 was 11.7 flashes per second with the greatest flash rate densities occurring over Lake Maracaibo (157 flashes per km2/year). Lloró, Chocó, Colombia had the most thunderstorm activity with 256 thunder days. The longest GLM flash spanned 673 km, the largest flash covered 114,997 km2, and the longest-lasting flash had a 13.496-s duration. The first case occurred over Rio Grande do Sul in Brazil, while the other two cases occurred in the central United States. All three extreme flashes are located in the stratiform regions of Mesoscale Convective Systems. The highest flash rate for a thunderstorm area feature was 17.6 flashes per second, while the largest thunderstorm was 216,865 km2 in size. Both storms occurred in South America. These initial results demonstrate the value that the development of a reprocessed GLM science product would offer and how such a product might be created at a reduced computational cost.
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Affiliation(s)
- Michael Peterson
- ISR-2, Los Alamos National Laboratory, Los Alamos, New Mexico, USA
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6
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Peterson M, Rudlosky S. The Time Evolution of Optical Lightning Flashes. JOURNAL OF GEOPHYSICAL RESEARCH. ATMOSPHERES : JGR 2019; 124:333-349. [PMID: 31632891 PMCID: PMC6800735 DOI: 10.1029/2018jd028741] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/30/2018] [Accepted: 12/01/2018] [Indexed: 06/10/2023]
Abstract
The composition and time evolution of lightning are examined using the Lighting Imaging Sensor (LIS). Frame-by-frame optical lightning measurements are clustered into features whose radiant energy, horizontal footprint, and timing may be analyzed statistically. A LIS series feature is used to describe distinct periods of near continuous illumination that persists over multiple LIS frames. Series are integrated into the LIS clustering hierarchy between the group and flash level. An average series illuminates 40% of the flash footprint while accounting for 20% of the flash radiance, and just 1% of the flash duration. LIS flashes typically contain optical emissions that are exceptionally radiant and may persist over multiple frames. Series features cluster these bright optical pulses, allowing their number and time separation to be quantified in each flash. This optical multiplicity averages 1.7 for flashes with at least one particularly radiant group. Multigroup series most often occur early in the flash duration with 13% to 18% at first light. Series are typically separated by 100 ms or more in multiseries flashes. Bright series, by contrast, typically occur in rapid succession, with at most a few dozen milliseconds between them. Because series are optical features, they may result from any physical process that produces strong optical emissions. The statistics presented herein support the idea that series may originate from multiple physical processes.
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Affiliation(s)
- Michael Peterson
- Earth System Science Interdisciplinary Center/Cooperative Institute for Climate and Satellites-Maryland, University of Maryland, College Park, MD, USA
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7
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Peterson M, Rudlosky S, Deierling W. Mapping the Lateral Development of Lightning Flashes From Orbit. JOURNAL OF GEOPHYSICAL RESEARCH. ATMOSPHERES : JGR 2018; 123:9674-9687. [PMID: 31807397 PMCID: PMC6894163 DOI: 10.1029/2018jd028583] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/26/2018] [Accepted: 08/13/2018] [Indexed: 06/10/2023]
Abstract
Optical lightning measurements from the Lightning Imaging Sensor (LIS) are used to map the lateral development of lightning flashes and produce statistics that describe their motion through the electrified cloud. This is accomplished by monitoring the frame-by-frame (group-level) evolution of the optical signals produced during each flash. While the optical flash properties recorded by LIS gravitate towards the most exceptional optical signals produced during the flash, group-level data describe the evolution and lateral development of the flash resulting from physical lightning process that emits enough light out of the top of the cloud to be detected from orbit. The groups that comprise LIS flashes constitute examples of complex lateral flash structure that can extend 80 km in length with dozens to hundreds of visible branches. The lateral development of individual flashes is described in terms of its speed and direction of motion, whether the development extends the overall length of the flash or reilluminates an existing segment, and whether it is directed inbound or outbound with respect to the origin. Sixty-five percent of propagating groups are directed outbound from the origin, 22% extend the length of the flash, and 3-5% reilluminate an existing branch. LIS flashes are commonly oriented from east to west and develop at speeds ranging from 104 to 106 m/s, consistent with large-scale leader development. These results provide evidence that lightning imagers may be used in conjunction with Lightning Mapping Array systems to document physical lightning phenomena across global domains.
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Affiliation(s)
- Michael Peterson
- Cooperative Institute for Climate and Satellites-Maryland, Earth System Science Interdisciplinary Center, University of Maryland, College Park, MD, USA
| | | | - Wiebke Deierling
- Department of Aerospace Engineering Sciences, University of Colorado Boulder, Boulder, CO, USA
- National Center for Atmospheric Research, Boulder, CO, USA
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8
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Mezentsev A, Østgaard N, Gjesteland T, Albrechtsen K, Lehtinen N, Marisaldi M, Smith D, Cummer S. Radio emissions from double RHESSI TGFs. JOURNAL OF GEOPHYSICAL RESEARCH. ATMOSPHERES : JGR 2016; 121:8006-8022. [PMID: 27774368 PMCID: PMC5054822 DOI: 10.1002/2016jd025111] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 03/17/2016] [Revised: 06/15/2016] [Accepted: 06/16/2016] [Indexed: 06/06/2023]
Abstract
A detailed analysis of Reuven Ramaty High Energy Solar Spectroscopic Imager (RHESSI) terrestrial gamma ray flashes (TGFs) is performed in association with World Wide Lightning Location Network (WWLLN) sources and very low frequency (VLF) sferics recorded at Duke University. RHESSI clock offset is evaluated and found to experience changes on the 5 August 2005 and 21 October 2013, based on the analysis of TGF-WWLLN matches. The clock offsets were found for all three periods of observations with standard deviations less than 100 μs. This result opens the possibility for the precise comparative analyses of RHESSI TGFs with the other types of data (WWLLN, radio measurements, etc.) In case of multiple-peak TGFs, WWLLN detections are observed to be simultaneous with the last TGF peak for all 16 cases of multipeak RHESSI TGFs simultaneous with WWLLN sources. VLF magnetic field sferics were recorded for two of these 16 events at Duke University. These radio measurements also attribute VLF sferics to the second peak of the double TGFs, exhibiting no detectable radio emission during the first TGF peak. Possible scenarios explaining these observations are proposed. Double (multipeak) TGFs could help to distinguish between the VLF radio emission radiated by the recoil currents in the +IC leader channel and the VLF emission from the TGF producing electrons.
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Affiliation(s)
- Andrew Mezentsev
- Birkeland Centre for Space Science, Department of Physics and Technology University of Bergen Bergen Norway
| | - Nikolai Østgaard
- Birkeland Centre for Space Science, Department of Physics and Technology University of Bergen Bergen Norway
| | - Thomas Gjesteland
- Birkeland Centre for Space Science, Department of Physics and Technology University of Bergen Bergen Norway; Department of Engineering Sciences University of Agder Grimstad Norway
| | - Kjetil Albrechtsen
- Birkeland Centre for Space Science, Department of Physics and Technology University of Bergen Bergen Norway
| | - Nikolai Lehtinen
- Birkeland Centre for Space Science, Department of Physics and Technology University of Bergen Bergen Norway
| | - Martino Marisaldi
- Birkeland Centre for Space Science, Department of Physics and Technology University of Bergen Bergen Norway; INAF-IASF National Institute for Astrophysics Bologna Italy
| | - David Smith
- Department of Physics, Santa Cruz Institute for Particle Physics University of California Santa Cruz California USA
| | - Steven Cummer
- Electrical and Computer Engineering Department Duke University Durham North Carolina USA
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9
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Observations of narrow bipolar events reveal how lightning is initiated in thunderstorms. Nat Commun 2016; 7:10721. [PMID: 26876654 PMCID: PMC4756383 DOI: 10.1038/ncomms10721] [Citation(s) in RCA: 147] [Impact Index Per Article: 18.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/19/2015] [Accepted: 01/14/2016] [Indexed: 11/08/2022] Open
Abstract
A long-standing but fundamental question in lightning studies concerns how lightning is initiated inside storms, given the absence of physical conductors. The issue has revolved around the question of whether the discharges are initiated solely by conventional dielectric breakdown or involve relativistic runaway electron processes. Here we report observations of a relatively unknown type of discharge, called fast positive breakdown, that is the cause of high-power discharges known as narrow bipolar events. The breakdown is found to have a wide range of strengths and is the initiating event of numerous lightning discharges. It appears to be purely dielectric in nature and to consist of a system of positive streamers in a locally intense electric field region. It initiates negative breakdown at the starting location of the streamers, which leads to the ensuing flash. The observations show that many or possibly all lightning flashes are initiated by fast positive breakdown.
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10
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Carlson BE, Liang C, Bitzer P, Christian H. Time domain simulations of preliminary breakdown pulses in natural lightning. JOURNAL OF GEOPHYSICAL RESEARCH. ATMOSPHERES : JGR 2015; 120:5316-5333. [PMID: 26664815 PMCID: PMC4671453 DOI: 10.1002/2014jd022765] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 10/25/2014] [Revised: 04/17/2015] [Accepted: 04/20/2015] [Indexed: 06/05/2023]
Abstract
UNLABELLED Lightning discharge is a complicated process with relevant physical scales spanning many orders of magnitude. In an effort to understand the electrodynamics of lightning and connect physical properties of the channel to observed behavior, we construct a simulation of charge and current flow on a narrow conducting channel embedded in three-dimensional space with the time domain electric field integral equation, the method of moments, and the thin-wire approximation. The method includes approximate treatment of resistance evolution due to lightning channel heating and the corona sheath of charge surrounding the lightning channel. Focusing our attention on preliminary breakdown in natural lightning by simulating stepwise channel extension with a simplified geometry, our simulation reproduces the broad features observed in data collected with the Huntsville Alabama Marx Meter Array. Some deviations in pulse shape details are evident, suggesting future work focusing on the detailed properties of the stepping mechanism. KEY POINTS Preliminary breakdown pulses can be reproduced by simulated channel extension Channel heating and corona sheath formation are crucial to proper pulse shape Extension processes and channel orientation significantly affect observations.
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Affiliation(s)
- B E Carlson
- Department of Physics, Carthage CollegeKenosha, Wisconsin, USA
- Birkeland Center for Space Science, University of BergenBergen, Norway
| | - C Liang
- Electrical Engineering Department, Stanford UniversityStanford, California, USA
| | - P Bitzer
- Department of Atmospheric Science, University of Alabama in HuntsvilleHuntsville, Alabama, USA
| | - H Christian
- Earth Systems Science Center, University of Alabama in HuntsvilleHuntsville, Alabama, USA
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11
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Liu N, Spiva N, Dwyer JR, Rassoul HK, Free D, Cummer SA. Upward electrical discharges observed above Tropical Depression Dorian. Nat Commun 2015; 6:5995. [PMID: 25607345 PMCID: PMC4354034 DOI: 10.1038/ncomms6995] [Citation(s) in RCA: 30] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/20/2014] [Accepted: 11/28/2014] [Indexed: 11/29/2022] Open
Abstract
Observation of upward electrical discharges from thunderstorms has been sporadically reported in the scientific literature. According to their terminal altitudes, they are classified as starters (20–30 km), jets (40–50 km) and gigantic jets (70–90 km). They not only have a significant impact on the occupied atmospheric volumes but also electrically couple different atmospheric regions. However, as they are rare and unpredictable, our knowledge of them has been built on observations that typically record only one type of such discharges. Here we report a close-distance observation of seven upward discharges including one starter, two jets and four gigantic jets above Tropical Depression Dorian. Our optical and electromagnetic data indicate that all events are of negative polarity, suggesting they are initiated in the same thundercloud charge region. The data also indicate that the lightning-like discharge channel can extend above thunderclouds by about 30 km, but the discharge does not emit low-frequency electromagnetic radiation as normal lightning. Upward electrical discharges from thunderstorms were discovered recently, and only a very limited set of observations exist because they are rare and unpredictable. Here, the authors present recordings of different types of the discharge above a storm, which contradict current theories of their origins.
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Affiliation(s)
- Ningyu Liu
- Department of Physics and Space Sciences, Florida Institute of Technology, 150 West University Boulevard, Melbourne, Florida 32901, USA
| | - Nicholas Spiva
- Department of Physics and Space Sciences, Florida Institute of Technology, 150 West University Boulevard, Melbourne, Florida 32901, USA
| | - Joseph R Dwyer
- Department of Physics and Space Sciences, Florida Institute of Technology, 150 West University Boulevard, Melbourne, Florida 32901, USA
| | - Hamid K Rassoul
- Department of Physics and Space Sciences, Florida Institute of Technology, 150 West University Boulevard, Melbourne, Florida 32901, USA
| | - Dwayne Free
- Space Coast Intelligent Solutions, Melbourne, Florida 32934, USA
| | - Steven A Cummer
- Department of Electrical and Computer Engineering, Duke University, Durham, North Carolina 27708, USA
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