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Neubert T, Østgaard N, Reglero V, Chanrion O, Heumesser M, Dimitriadou K, Christiansen F, Budtz-Jørgensen C, Kuvvetli I, Rasmussen IL, Mezentsev A, Marisaldi M, Ullaland K, Genov G, Yang S, Kochkin P, Navarro-Gonzalez J, Connell PH, Eyles CJ. A terrestrial gamma-ray flash and ionospheric ultraviolet emissions powered by lightning. Science 2020; 367:183-186. [PMID: 31826957 DOI: 10.1126/science.aax3872] [Citation(s) in RCA: 42] [Impact Index Per Article: 10.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/02/2019] [Accepted: 10/31/2019] [Indexed: 11/02/2022]
Abstract
Terrestrial gamma-ray flashes (TGFs) are transient gamma-ray emissions from thunderstorms, generated by electrons accelerated to relativistic energies in electric fields. Elves are ultraviolet and optical emissions excited in the lower ionosphere by electromagnetic waves radiated from lightning current pulses. We observed a TGF and an associated elve using the Atmosphere-Space Interactions Monitor on the International Space Station. The TGF occurred at the onset of a lightning current pulse that generated an elve, in the early stage of a lightning flash. Our measurements suggest that the current onset is fast and has a high amplitude-a prerequisite for elves-and that the TGF is generated in the electric fields associated with the lightning leader.
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Affiliation(s)
- Torsten Neubert
- National Space Institute, Technical University of Denmark (DTU Space), Kongens Lyngby, Denmark.
| | - Nikolai Østgaard
- Birkeland Centre for Space Science, Department of Physics and Technology, University of Bergen, Bergen, Norway
| | - Victor Reglero
- Image Processing Laboratory, University of Valencia, Valencia, Spain
| | - Olivier Chanrion
- National Space Institute, Technical University of Denmark (DTU Space), Kongens Lyngby, Denmark
| | - Matthias Heumesser
- National Space Institute, Technical University of Denmark (DTU Space), Kongens Lyngby, Denmark
| | - Krystallia Dimitriadou
- National Space Institute, Technical University of Denmark (DTU Space), Kongens Lyngby, Denmark
| | - Freddy Christiansen
- National Space Institute, Technical University of Denmark (DTU Space), Kongens Lyngby, Denmark
| | - Carl Budtz-Jørgensen
- National Space Institute, Technical University of Denmark (DTU Space), Kongens Lyngby, Denmark
| | - Irfan Kuvvetli
- National Space Institute, Technical University of Denmark (DTU Space), Kongens Lyngby, Denmark
| | - Ib Lundgaard Rasmussen
- National Space Institute, Technical University of Denmark (DTU Space), Kongens Lyngby, Denmark
| | - Andrey Mezentsev
- 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.,Astrophysics and Space Science Observatory, National Institute for Astrophysics, Bologna, Italy
| | - Kjetil Ullaland
- Birkeland Centre for Space Science, Department of Physics and Technology, University of Bergen, Bergen, Norway
| | - Georgi Genov
- Birkeland Centre for Space Science, Department of Physics and Technology, University of Bergen, Bergen, Norway
| | - Shiming Yang
- Birkeland Centre for Space Science, Department of Physics and Technology, University of Bergen, Bergen, Norway
| | - Pavlo Kochkin
- Birkeland Centre for Space Science, Department of Physics and Technology, University of Bergen, Bergen, Norway
| | | | - Paul H Connell
- Image Processing Laboratory, University of Valencia, Valencia, Spain
| | - Chris J Eyles
- Image Processing Laboratory, University of Valencia, Valencia, Spain
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Østgaard N, Christian HJ, Grove JE, Sarria D, Mezentsev A, Kochkin P, Lehtinen N, Quick M, Al‐Nussirat S, Wulf E, Genov G, Ullaland K, Marisaldi M, Yang S, Blakeslee RJ. Gamma Ray Glow Observations at 20-km Altitude. J Geophys Res Atmos 2019; 124:7236-7254. [PMID: 31598449 PMCID: PMC6774313 DOI: 10.1029/2019jd030312] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 01/14/2019] [Revised: 03/18/2019] [Accepted: 04/24/2019] [Indexed: 06/10/2023]
Abstract
In the spring of 2017 an ER-2 aircraft campaign was undertaken over continental United States to observe energetic radiation from thunderstorms and lightning. The payload consisted of a suite of instruments designed to detect optical signals, electric fields, and gamma rays from lightning. Starting from Georgia, USA, 16 flights were performed, for a total of about 70 flight hours at a cruise altitude of 20 km. Of these, 45 flight hours were over thunderstorm regions. An analysis of two gamma ray glow events that were observed over Colorado at 21:47 UT on 8 May 2017 is presented. We explore the charge structure of the cloud system, as well as possible mechanisms that can produce the gamma ray glows. The thundercloud system we passed during the gamma ray glow observation had strong convection in the core of the cloud system. Electric field measurements combined with radar and radio measurements suggest an inverted charge structure, with an upper negative charge layer and a lower positive charge layer. Based on modeling results, we were not able to unambiguously determine the production mechanism. Possible mechanisms are either an enhancement of cosmic background locally (above or below 20 km) by an electric field below the local threshold or an enhancement of the cosmic background inside the cloud but then with normal polarity and an electric field well above the Relativistic Runaway Electron Avalanche threshold.
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Affiliation(s)
- N. Østgaard
- Birkeland Centre for Space ScienceUniversity of BergenBergenNorway
| | - H. J. Christian
- Department of Atmospheric ScienceUniversity of AlabamaHuntsvilleALUSA
| | - J. E. Grove
- U.S. Naval Research LaboratoryWashingtonDCUSA
| | - D. Sarria
- Birkeland Centre for Space ScienceUniversity of BergenBergenNorway
| | - A. Mezentsev
- Birkeland Centre for Space ScienceUniversity of BergenBergenNorway
| | - P. Kochkin
- Birkeland Centre for Space ScienceUniversity of BergenBergenNorway
| | - N. Lehtinen
- Birkeland Centre for Space ScienceUniversity of BergenBergenNorway
| | - M. Quick
- NASA Marshal Space Flight CenterHuntsvilleALUSA
| | - S. Al‐Nussirat
- Department of Physics and AstronomyLouisiana State UniversityBaton RougeLAUSA
| | - E. Wulf
- U.S. Naval Research LaboratoryWashingtonDCUSA
| | - G. Genov
- Birkeland Centre for Space ScienceUniversity of BergenBergenNorway
| | - K. Ullaland
- Birkeland Centre for Space ScienceUniversity of BergenBergenNorway
| | - M. Marisaldi
- Birkeland Centre for Space ScienceUniversity of BergenBergenNorway
| | - S. Yang
- Birkeland Centre for Space ScienceUniversity of BergenBergenNorway
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Kochkin P, Sarria D, Skeie C, van Deursen APJ, de Boer AI, Bardet M, Allasia C, Flourens F, Østgaard N. In-Flight Observation of Positron Annihilation by ILDAS. J Geophys Res Atmos 2018; 123:8074-8090. [PMID: 31032163 PMCID: PMC6473548 DOI: 10.1029/2018jd028337] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 01/16/2018] [Revised: 06/13/2018] [Accepted: 06/14/2018] [Indexed: 06/09/2023]
Abstract
We report a 511-keV photon flux enhancement that was observed inside a thundercloud and is a result of positron annihilation. The observation was made with the In-flight Lightning Damage Assessment System (ILDAS) on board of an A340 test aircraft. The aircraft was intentionally flying through a thunderstorm at 12-km altitude over Northern Australia in January 2016. Two gamma ray detectors showed a significant count rate increase synchronously with fast electromagnetic field variations registered by an on-board antenna. A sequence of 10 gamma ray enhancements was detected, each lasted for about 1 s. Their spectrum mainly consists of 511-keV photons and their Compton component. The local electric activity during the emission was identified as a series of static discharges of the aircraft. A full-scale Geant4 model of the aircraft was created to estimate the emission area. Monte Carlo simulation indicated that the positrons annihilated in direct vicinity or in the aircraft body.
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Affiliation(s)
| | - D. Sarria
- BCSSUniversity of BergenBergenNorway
| | - C. Skeie
- BCSSUniversity of BergenBergenNorway
| | - A. P. J. van Deursen
- Electrical Engineering DepartmentEindhoven University of TechnologyEindhovenNetherlands
| | - A. I. de Boer
- The Netherlands Aerospace CentreAmsterdamNetherlands
| | - M. Bardet
- The Netherlands Aerospace CentreAmsterdamNetherlands
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4
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Kochkin P, van Deursen APJ, Marisaldi M, Ursi A, de Boer AI, Bardet M, Allasia C, Boissin J, Flourens F, Østgaard N. In-Flight Observation of Gamma Ray Glows by ILDAS. J Geophys Res Atmos 2017; 122:12801-12811. [PMID: 29497588 PMCID: PMC5815387 DOI: 10.1002/2017jd027405] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 07/04/2017] [Revised: 11/02/2017] [Accepted: 11/02/2017] [Indexed: 06/08/2023]
Abstract
An Airbus A340 aircraft flew over Northern Australia with the In-Flight Lightning Damage Assessment System (ILDAS) installed onboard. A long-duration gamma ray emission was detected. The most intense emission was observed at 12 km altitude and lasted for 20 s. Its intensity was 20 times the background counts, and it was abruptly terminated by a distant lightning flash. In this work we reconstruct the aircraft path and event timeline. The glow-terminating flash triggered a discharge from the aircraft wing that was recorded by a video camera operating onboard. Another count rate increase was observed 6 min later and lasted for 30 s. The lightning activity as reported by ground networks in this region was analyzed. The measured spectra characteristics of the emission were estimated.
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Affiliation(s)
| | - A. P. J. van Deursen
- Electrical Engineering DepartmentEindhoven University of TechnologyEindhovenNetherlands
| | | | | | | | - M. Bardet
- Netherlands Aerospace CentreAmsterdamNetherlands
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Østgaard N, Carlson BE, Nisi RS, Gjesteland T, Grøndahl Ø, Skeltved A, Lehtinen NG, Mezentsev A, Marisaldi M, Kochkin P. Relativistic electrons from sparks in the laboratory. J Geophys Res Atmos 2016; 121:2939-2954. [PMID: 27840781 PMCID: PMC5080862 DOI: 10.1002/2015jd024394] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 10/23/2015] [Revised: 02/22/2016] [Accepted: 02/24/2016] [Indexed: 06/06/2023]
Abstract
Discharge experiments were carried out at the Eindhoven University of Technology in 2013. The experimental setup was designed to search for electrons produced in meter-scale sparks using a 1 MV Marx generator. Negative voltage was applied to the high voltage (HV) electrode. Five thin (1 mm) plastic detectors (5 cm2 each) were distributed in various configurations close to the spark gap. Earlier studies have shown (for HV negative) that X-rays are produced when a cloud of streamers is developed 30-60 cm from the negative electrode. This indicates that the electrons producing the X-rays are also accelerated at this location, that could be in the strong electric field from counterstreamers of opposite polarity. Comparing our measurements with modeling results, we find that ∼300 keV electrons produced about 30-60 cm from the negative electrode are the most likely source of our measurements. A statistical analysis of expected detection of photon bursts by these fiber detectors indicates that only 20%-45% of the detected bursts could be from soft (∼10 keV) photons, which further supports that the majority of detected bursts are produced by relativistic electrons.
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Affiliation(s)
- N. Østgaard
- Birkeland Centre for Space Science, Department of Physics and TechnologyUniversity of BergenBergenNorway
| | - B. E. Carlson
- Birkeland Centre for Space Science, Department of Physics and TechnologyUniversity of BergenBergenNorway
- Department of PhysicsCarthage CollegeKenoshaWisconsinUSA
| | - R. S. Nisi
- Birkeland Centre for Space Science, Department of Physics and TechnologyUniversity of BergenBergenNorway
| | - T. Gjesteland
- Birkeland Centre for Space Science, Department of Physics and TechnologyUniversity of BergenBergenNorway
| | - Ø. Grøndahl
- Birkeland Centre for Space Science, Department of Physics and TechnologyUniversity of BergenBergenNorway
| | - A. Skeltved
- Birkeland Centre for Space Science, Department of Physics and TechnologyUniversity of BergenBergenNorway
| | - N. G. Lehtinen
- Birkeland Centre for Space Science, Department of Physics and TechnologyUniversity of BergenBergenNorway
| | - A. Mezentsev
- Birkeland Centre for Space Science, Department of Physics and TechnologyUniversity of BergenBergenNorway
| | - M. Marisaldi
- Birkeland Centre for Space Science, Department of Physics and TechnologyUniversity of BergenBergenNorway
- INAF‐IASFNational Institute for AstrophysicsBolognaItaly
| | - P. Kochkin
- Birkeland Centre for Space Science, Department of Physics and TechnologyUniversity of BergenBergenNorway
- Department of Electric EngineeringTechnische Iniversiteit EindhovenEindhovenNetherlands
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6
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Carlson BE, Østgaard N, Kochkin P, Grondahl Ø, Nisi R, Weber K, Scherrer Z, LeCaptain K. Meter-scale spark X-ray spectrum statistics. J Geophys Res Atmos 2015; 120:11191-11202. [PMID: 27867779 PMCID: PMC5102163 DOI: 10.1002/2015jd023849] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 06/24/2015] [Revised: 10/16/2015] [Accepted: 10/19/2015] [Indexed: 06/06/2023]
Abstract
X-ray emission by sparks implies bremsstrahlung from a population of energetic electrons, but the details of this process remain a mystery. We present detailed statistical analysis of X-ray spectra detected by multiple detectors during sparks produced by 1 MV negative high-voltage pulses with 1 μs risetime. With over 900 shots, we statistically analyze the signals, assuming that the distribution of spark X-ray fluence behaves as a power law and that the energy spectrum of X-rays detectable after traversing ∼2 m of air and a thin aluminum shield is exponential. We then determine the parameters of those distributions by fitting cumulative distribution functions to the observations. The fit results match the observations very well if the mean of the exponential X-ray energy distribution is 86 ± 7 keV and the spark X-ray fluence power law distribution has index -1.29 ± 0.04 and spans at least 3 orders of magnitude in fluence.
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Affiliation(s)
- B. E. Carlson
- Department of PhysicsCarthage CollegeKenoshaWisconsinUSA
- Birkeland Center for Space ScienceUniversity of BergenBergenNorway
| | - N. Østgaard
- Birkeland Center for Space ScienceUniversity of BergenBergenNorway
| | - P. Kochkin
- Technische Universiteit EindhovenEindhovenNetherlands
| | - Ø. Grondahl
- Birkeland Center for Space ScienceUniversity of BergenBergenNorway
| | - R. Nisi
- Birkeland Center for Space ScienceUniversity of BergenBergenNorway
| | - K. Weber
- Department of PhysicsCarthage CollegeKenoshaWisconsinUSA
| | - Z. Scherrer
- Department of PhysicsCarthage CollegeKenoshaWisconsinUSA
| | - K. LeCaptain
- Department of PhysicsCarthage CollegeKenoshaWisconsinUSA
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