Papers with references to CRD 2021


1. Generation possibility of gamma-ray glows induced by photonuclear reactions

Authors: G. Diniz 1,*, I.S. Ferreira 2 , Y. Wada 1 , T. Manoto1


Abstract: Relativistic runaway electron avalanches (RREAs) imply a large multiplication of high energy electrons (∼1 MeV). Two factors are necessary for this phenomenon: a high electric field sustained over a large distance and an energetic particle to serve as a seed. The former sustains particle energies as they keep colliding and lose energy randomly; and the latter serves as a multiplication starting point that promotes avalanches. RREA is usually connected to both terrestrial gamma-ray flashes (TGFs) and gamma-ray glows...Read more...


2. Toward a theory of ball lightning occurring in houses and aircraft

Authors: John J. Lowke a,* , Wilfried Heil b, Eugene Tam a, Anthony B. Murphy a

Abstract: Gas discharge properties have been calculated, considering electrons, negative ions, positive ions and the metastable singlet delta oxygen molecules, to assess the possibility of ball lightning resulting from an electrical discharge. It is found that if the metastable molecules have very large densities of the order of 1017 cm− 3, a stable ball-like plasma of electrons, positive ions, negative ions and metastable molecules is obtained, with electron densities of ~1011 cm− 3. The ball can exist independent of the electrodes. There is an equilibrium within the ball between the detachment of electrons from negative ions by the metastables and the re-attachment of electrons to oxygen atoms reforming negative ions...Read more...


3. Terrestrial Gamma-ray Flashes and Other High Energy Atmospheric Phenomena: An Overview

Authors: Paras Manoj Kumar1* and Rani Pooja2

Abstract: Extraordinarily bright events with highly energetic radiation in the form of bursts of hard X-rays and γrays of short durations have been detected in our atmosphere by scientific community routinely during strong thunderstorms and lightning activity. Terrestrial Gamma-ray Flashes (TGFs) are very short (< 1 ms) bursts of highly energetic gamma-ray photons which are generated during powerful thunderstorms and have been detected by both airborne as well as ground based experiments. TGFs driven source has been an active area of research since their accidental discovery by Burst and Transient Source Experiment detector, on board the Compton Gamma-ray Observatory in 1994...Read more...


4. Transit of the Sun across constellation Libra and variation of secondary gamma radiation flux in the month of October and November, 2020 at Udaipur, India

Authors: Devendra Pareek1, Prajesh Purohit1

Abstract: During transit of the Sun across the constellation Libra in the month of October and November 2020 we experimentally observed the variation of secondary gamma radiation flux (SGR) at Udaipur (270 43’ 12.00” N, 750 28’ 48.01” E), India. We interpret such variation of SGR flux on the basis of gravitational lensing effect produced by the Sun and constellation Libra, radiation from constellation and gravitational pull-on background radiation by constellation Libra and Sun...Read more...

5. ОЦЕНКА РАСПРЕДЕЛЕНИЯ ЭЛЕКТРИЧЕСКОГО ЗАРЯДА В ОБЛАКЕ ПО ДАННЫМ О ВАРИАЦИИ ПОТОКА ЭНЕРГИЧНЫХ ЧАСТИЦ ПОД ОБЛАКОМ

Автор: Е. К. Свечникова1,2,*, Н. В. Ильин1,  Е. А. Мареев1,2

Аннотация: Увеличение потока энергичных частиц под грозовыми облаками обусловлено размножением и ускорением частиц вторичных космических лучей в электрическом поле облака. Изучение механизмов размножения энергичных частиц требует выяснения электрических свойств облаков. Предложен новый способ оценки электрической структуры облака, создающего поток энергичных частиц. Способ основан на использовании результатов наземных измерений напряженности электрического поля и потока энергичных частиц под облаком. С помощью разработанной методики исследованы облака, создающие нисходящие...Read more...

6. A Rapid Gamma-Ray Glow Flux Reduction Observed From 20 km Altitude

Authors: P. Kochkin1 , D. Sarria1 , N. Lehtinen1 , A. Mezentsev1 , S. Yang1, G. Genov1 , K. Ullaland1 , M. Marisaldi1 , N. Østgaard1 , H. J. Christian2, J. E. Grove3 , M. Quick4, S. Al-Nussirat2, and E. Wulf

Abstract: Two gamma-ray glows were observed by a high-altitude NASA ER-2 aircraft flying at 20 km altitude over a thunderstorm in Colorado, USA. The flux of the first glow rapidly intensified and then abruptly decreased within a few tens of milliseconds. On a timescale of seconds, the flux decrease occurred simultaneously with a hybrid intra-cloud/cloud-to-ground lightning discharge beneath the aircraft. However, a more detailed analysis of the discharge dynamics indicated that the discharge activity was unusually calm during the actual period of the flux decrease. The lightning was observed with on-board antennas, optical sensor, and ground-based lightning mapping and location networks. Its closest activity was 12 km away from the aircraft, below and slightly ahead the course...Read more...

7. Relativistic runaway electron avalanches within 2 complex thunderstorm electric field structures 

Authors: E. Stadnichuk1,2, E. Svechnikova4, A. Nozik1,5, D. Zemlianskaya1,33 , T.Khamitov1,3, M. Zelenyy1,3, and M. Dolgonosov6


Abstract: Relativistic runaway electron avalanches (RREAs) are generally accepted as a source of thunderstorms gamma-ray radiation. Avalanches can multiply in the electric field via the relativistic feedback mechanism based on processes with gamma-rays and positrons.
This paper shows that a non-uniform electric field geometry can lead to the new RREAs multiplication mechanism - “reactor feedback”, due to the exchange of high-energy par24 ticles between different accelerating regions within a thundercloud. A new method for the numerical simulation of RREA dynamics within heterogeneous elect...Read more...

8. Characteristics and Meteorological Environment of Terrestrial Gamma-ray Flashes


Author: Carolina Maiorana

Abstract:Terrestrial Gamma-ray Flashes (TGFs) are sub-millisecond bursts of gamma radiation associated with lightning activity and are the manifestation of the most energetic natural particle acceleration processes on Earth. The goal of this thesis is to explore the impact of geography and the seasonal cycle in their production and the characteristics of the parent storms. TGFs were first discovered in 1991 by the Burst and Transient.Source Experiment (BATSE) instrument onboard Compton Gamma-Ray Observatory
and have subsequently been studied by a few other missions: Reuven Ramaty High Energy Solar Spectroscopic Imager (RHESSI) (Smith et al., 2005), now decommissioned; Astro-rivelatore Gamma a Immagini Leggero (AGILE) (Marisaldi et al., 2010); Fermi (Briggs et al., 2013); and Atmosphere Space Interactions Monitor (ASIM) (Neubert et al., 2019), launched in 2018...
Read more...

9. A new analysis of the PeVatron candidate HESS J1646–458 using a novel analysis technique

Author: Andreas Christopher Specovius

Abstract: The observed spectrum of cosmic rays (CRs), arriving at earth from the universe, requires the existence of cosmic particle accelerators, able to produce PeV energy particles. The detection of the very high energy (VHE) γ-ray source HESS J1646–458 proposed the
young massive stellar cluster (SC) Westerlund 1 (Wd1) as such a galactic PeVatron. However, the nature of HESS J1646–458 could not be firmly established. Using a significantly enlarged set of ∼162.6 h of H.E.S.S. γ-ray data, a new analysis...Read more...

10. Hazards to Aircraft Crews, Passengers, and Equipment from Thunderstorm-Generated X-rays and Gamma-Rays

Author: Karl D. Stephan 1 and Mikhail L. Shmatov 2,*

Abstract: Both observational and theoretical research in the area of atmospheric high-energy physics since about 1980 has revealed that thunderstorms produce X-rays and gamma-rays into the MeV region by a number of mechanisms. While the nature of these mechanisms is still an area of active research, enough observational and theoretical data exists to permit an evaluation of hazards presented by ionizing radiation from thunderstorms to aircraft crew, passengers, and equipment. In this paper, we use data from existing studies to evaluate these hazards in a quantitative way. We find that hazards to humans are generally low, although with the possibility of an isolated rare incident giving rise to enough radiation dose to produce noticeable symptoms...Read more...

11. Survey on Electrical Activity in Earth’s Atmosphere

Author: Manoj Kumar Paras1 and Pooja Rani2 

Abstract: Lightning discharge is a spectacular, luminous and one of the most dangerous short lived phenomenon which occurs in the Earth‟s atmosphere ranging from troposphere to the lower ionosphere. Lightning in troposphere is mainly classified as cloud-to-ground (CG) lightning, intra-cloud (IC) lightning and inter-cloud or cloud-to-cloud (CC) lightning discharges. It is assumed that these discharges are
caused by the electrically charged thunderclouds. CG lightning has been studied more and is further categorized as positive CG and negative CG lightning. Positive CG lightning is more powerful and accounts only (5-10) percent of the total global lightning and may carry a peak current of >300 kA. An entire family of other electrical discharges also has been reported by the scientific community...Read more...

12. Detecting Ground Level Enhancements Using Soil Moisture Sensor Networks

Author: A. D. P. Hands1 , F. Baird1 , K. A. Ryden1 , C. S. Dyer1 , F. Lei1, J. G. Evans2 , J. R. Wallbank2, M. Szczykulska2, D. Rylett2 , R. Rosolem3 , S. Fowler3, D. Power3, and E. M. Henley 

Abstract: Ground level enhancements (GLEs) are space weather events that pose a potential hazard to the aviation environment through single event effects in avionics and increased dose to passengers and crew. The existing ground level neutron monitoring network provides continuous and well-characterized measurements of the radiation environment. However, there are only a few dozen active stations worldwide, and there has not been a UK-based station for several decades. Much smaller neutron detectors are increasingly deployed throughout the world with the purpose of using secondary neutrons from cosmic rays to monitor local soil moisture conditions (COSMOS). Space weather signals from GLEs and Forbush decreases have been identified in COSMOS data. Monte Carlo simulations of atmospheric radiation propagation show that a single COSMOS detector is sufficient to detect the signal of a medium-strength (10%–100% increase above background) GLE at high statistical significance, including at fine temporal resolution...Read more...

13. ВЫСОКОЭНЕРГИЧНЫЕ СОБЫТИЯ В АТМОСФЕРЕ И ИХ СВЯЗЬ С ЭЛЕКТРИЧЕСКОЙ СТРУКТУРОЙ ОБЛАКА

Aвтор: Е. К. Свечникова

Абстракт: Грозовые события, происходящие в атмосфере Земли, являются источником потоков электронов, излучающих фотоны с энергией от долей до сотен МэВ, которые могут быть зарегистрированы как на поверхности Земли, так и на высоте 450–550 км [1]. Механизм энергичного излучения облаков ещё мало изучен, что связано с недостатком сведений о физических свойствах облаков, создающих энергичное излучение. Интерес представляют и метеорологические характеристики, и распределение заряда в облаке. Совокупный анализ этих свойств способен дать новую информацию о механизмах развития энергичного излучения и процессах разделения заряда в облаке... Читать дальше...

14. Thunderstorms Producing Sferic-Geolocated Gamma-Ray Flashes Detected by TETRA-II

Authors: Deirdre Smith1 , Jill Trepanier1 , Samer T. Alnussirat2 , Michael L. Cherry2, Marc D. Legault3, and Donald J. Pleshinger4

Abstract: The terrestrial gamma-ray flash (TGF) and Energetic Thunderstorm Rooftop Array (TETRAII) detected 22 X-ray/gamma-ray flash events associated with lightning between October 2015 and March 2019 across three ground-based detector locations in subtropical and tropical climates in Louisiana, Puerto Rico, and Panama. Each detector array consists of a set of bismuth germanate scintillators that record X-ray and gamma-ray bursts over the energy range 50 keV–6 MeV (million electron volts). TETRAII events have characteristics similar to both X-ray bursts associated with lightning leaders and TGFs: sub-millisecond duration, photons up to MeV energies, and association with nearby lightning (typically
within 3 km). About 20 of the 22 events are geolocated to individual lightning strokes via spatiotemporally coincident sferics...Read more...

15. Influence of Solar Wind on Secondary Cosmic Rays and Atmospheric Electricity

Authors: Jaroslav Chum1*,Marek Kollárik2, Ivana Kolmašová1,3, Ronald Langer2, Jan Rusz1, Dana Saxonbergová1 and Igor Strhárský2

Abstract: A relationship between the heliospheric magnetic field, atmospheric electric field, lightning activity, and secondary cosmic rays measured on the high mount of Lomnický Štít (2,634 m a.s.l.), Slovakia, during the declining phase of the solar cycle 24 is investigated with a focus on variations related to solar rotation (about 27 days). The secondary cosmic rays are detected using a neutron monitor and the detector system SEVAN, which distinguishes between different particles and energies. Using spectral analysis, we found distinct ∼27-day periodicities in variations of Bx and By components of the heliospheric magnetic field and in pressure-corrected measurements of secondary cosmic rays. The 27-day variations of secondary cosmic rays, on average, advanced and lagged the variations of Bx and By components by about 40° and −140°, respectively....Read more...

16. Lightning inception by Hydrometeors

Authors: Shahriar Mirpour

Abstract: Although plenty of studies have been conducted over the years, the question of how lightning is initiated inside thunderclouds is still one of the biggest unsolved problems in lightning physics. The measured ambient electric field of a thundercloud is much lower than that of the well-known electric breakdown field. This thesis treats an experimental and theoretical investigation of discharge inception under different experimental conditions. In the first part, we investigate the role and availability of free electrons in the discharge inception process. Streamer initiation under repetitive pulsed discharges is studied for different gas compositions. In repetitive discharges, an important point is the role of leftover charges that may induce an in-homogeneous charge distribution in the discharge gap that can be source of free electrons production. To address this subject, we measured the inception times for hundreds of pulses which gives us some insights on the temporal and spatial distribution of the free electron sources.....Read more...