
2024-04-29 08:46:09 |
Research papers published by CRD scientists in the first quarter of 2024 and citations summary
In a remarkable first quarter of 2024, scientists from the Cosmic Ray Division at the Alikhanyan National Laboratory have unveiled significant findings in high-energy atmospheric physics and solar physics, contributing important insights into thunderstorm-induced particle dynamics, magnetospheric disturbances, and atmospheric electric fields. These discoveries advance our understanding of atmospheric electric fields, the operation of the electron accelerators in thunderclouds, and Space Weather issues.
- Physical Review D 109, 062003 (2024)
Atmospheric Positron Flux Modulation During Thunderstorms
Authors: A. Chilingarian, B. Sargsyan
We report the discovery of a novel phenomenon in high-energy atmospheric physics: a significant increase in ground-level positrons during thunderstorm events. This phenomenon is associated with the development of a Lower Positively Charged Region (LPCR) at the base of thunderclouds. As electric field strength in the lower atmosphere surpasses a critical threshold, seed electrons from cosmic rays undergo acceleration, leading to the formation of relativistic runaway electron avalanches. These avalanches, consisting of millions of electrons and gamma rays with energies reaching up to 50 MeV, modify the electric field's polarity near the Earth's surface. This alteration in field polarity causes a deceleration in electron movement and an acceleration in positron movement, thereby augmenting the flux of 511 keV "annihilation" gamma rays. By detecting these gamma rays, we can trace the formation of the LPCR and monitor the dynamics of the charge structure within the lower thundercloud regions. Our findings underscore the modulation of atmospheric electric fields during thunderstorms and their influence on fluxes of cosmic ray electrons, gamma rays, muons, and neutrons. This research highlights the importance of charged structures within thunderclouds in modulating positron fluxes.
2. Advances in Space Research, in press, doi.org/10.1016/j.asr.2024.02.041A groundbreaking Thunderstorm Ground Enhancement (TGE) event was recorded on May 23, 2023, at Mount Aragats, Armenia's highest peak. This event demonstrated a peak flux intensity exceeding 3 million particles per minute per square meter for energies above 0.4 MeV, with a measured fluence of approximately 700 particles/cm². The sophisticated instrumentation at the Aragats research station, comprising various spectrometers and detectors, facilitated a precise cross-correlation of measurements. Observations confirmed a flux of high-energy electrons at levels around 55,000 particles per minute per square meter for energies exceeding 10 MeV. Additional data, including cloud base heights and corona discharge detections, supported the recorded electric field intensity of approximately 2.1 kV/cm at elevations 50–100 m above ground level. These observations affirm the universality and significance of TGE as a major atmospheric event, impacting the global electrical circuit and necessitating integration into Earth’s atmospheric models for enhanced safety in aviation and aerospace operations.
3. Advances in Space Research, in press, doi.org/10.1016/j.asr.2024.03.013
Our study elucidates the correlation between sudden increases in Natural Gamma Radiation (NGR) and enhanced atmospheric electric fields during thunderstorms, specifically attributing these spikes to Thunderstorm Ground Enhancements (TGEs). TGEs, characterized by transient, several-minute-long increases in particle fluxes, originate from natural electron accelerators within thunderclouds. Additionally, more prolonged yet less pronounced increases in NGR, which can last several hours, are attributed to gamma radiation from radon progeny and enhanced positron fluxes. This radon, released from terrestrial materials, is transported upward by the Near-Surface Electric Field (NSEF). We employ an ORTEC detector and custom-built large NaI (Tl) spectrometers with lead filters to distinguish between cosmic ray fluxes and radon progeny radiation accurately. Our detailed analysis differentiates the radiation enhancements during positive and negative NSEF episodes. The resultant comprehensive dataset provides critical measurements of principal isotopes and positron flux during thunderstorms compared to fair weather conditions, underscoring the global significance of these phenomena in atmospheric processes. The inclusion of these effects in numerical models of Earth’s atmosphere is essential due to their substantial planetary impact.
5. EPL - A Letter Journal Exploring Frontiers of Physics 146 (2024) 24001
https://creativecommons.org/licenses/by-nc-nd/3.0
Helio-Magnetic Disturbance Impact on Ground-Based Cosmic-Ray Detectors, 5 November 2023
Authors: A. Chilingarian1, T. Karapetyan1, B. Sargsyan1, M. Zazyan1, J. Knapp2, M. Walter2, T. Rehm3
The recent upsurge in solar activity in fall 2023, following a period of relative calm during the 24th solar activity cycle, signals the approach of the solar maximum of the 25th cycle expected in 2024. The complex interplay between disturbed interplanetary magnetic fields and Earth’s geomagnetic fields results in a variety of effects, ranging from potential damage to satellite electronics to the production of spectacular auroras. Understanding these interactions is increasingly vital as large magnetized clouds ejected from the Sun influence near-Earth environments. Networks of ground-based particle detectors provide essential insights into these processes by continuously monitoring cosmic ray flux. This letter discusses a rare Magnetospheric Effect observed by these networks at middle latitudes on mountaintops and presents, for the first time, the energy spectrum of the particles responsible for the observed enhancement in count rates, highlighting the intricate solar-magnetospheric interactions.
6. Physics Open 18 (2024) 100202
https://doi.org/10.1016/j.physo.2023.100202
Spatial and Temporal Structure of Thunderstorm Ground Enhancements (TGEs) Observed on Aragats, May 23, 2023
Authors: A. Chilingarian, D. Pokhsraryan, F. Zagumennov, M. Zazyan
7. Astroparticle Physics 156 (2024) 102924
https://doi.org/10.1016/j.astropartphys.2024.102924
Comparative Analysis of Energy Spectra from Thunderstorm Ground Enhancements (TGEs) at Zugspitze and Aragats
*Authors: A. Chilingarian a, T. Karapetyan a, B. Sargsyan a, J. Knapp b, M. Walter b, T. Rehm c
This research presents the first comparative analysis of the energy spectra from Thunderstorm Ground Enhancements (TGEs) recorded at the SEVAN detector sites on Zugspitze and Aragats. Significant advancements were made by updating the electronics board of the SEVAN detector at the Umwelt-Forschungs-Station (UFS, Schneefernerhaus, 2650 m asl), enabling the precise measurement of energy releases up to 50 MeV. This enhancement allows for a clear distinction between Radon progeny gamma radiation and the energetic products of relativistic runaway electron avalanches. On May 23, 2023, the first TGE registered on Zugspitze revealed a gamma-ray flux enhancement of 44%, correlating to a count rate peak enhancement of 44σ. Simultaneously, a large TGE observed on Aragats demonstrated a flux increase exceeding 200% over fair-weather levels, with a peak significance of 400σ. This paper explores the newly expanded capabilities of the SEVAN detectors and their pivotal role in advancing high-energy atmospheric physics research by offering insights into the mechanisms behind thunderstorm-induced particle accelerations and their potential implications.
8. Mendeley Data, V1, (2024) doi: 10.17632/z4ry54hccb.1
https://data.mendeley.com/datasets/z4ry54hccb/1
Comprehensive Catalog of Extreme Thunderstorm Ground Enhancements Registered on Aragats in 2023
Authors: Ashot Chilingarian, Tigran Karapetyan, Davit Aslanyan, Balabek Sargsyan
9. Atmospheric Research, in press, 107403, https://doi.org/10.1016/j.atmosres.2024.107403
Corrigendum to "Termination of Thunderstorm-Related Bursts of Energetic Radiation and Particles by Inverted Intracloud and Hybrid Lightning Discharges"
Authors: A. Chilingarian, Y. Khanikyants, V. Rakov
In this corrigendum, we address findings from our expanded analysis covering 163 Thunderstorm Ground Enhancement (TGE) events from 2012 to 2021, a significantly larger dataset than the 49 events analyzed in our original 2020 study. The revised analysis provides new insights that challenge some of our earlier conclusions regarding the frequency and impact of lightning discharges on TGEs. Specifically, we found that the association between inverted intracloud (IC) flashes and hybrid flashes and the resultant particle flux reductions was not as pronounced as previously reported. This corrigendum is part of our commitment to updating the scientific community on our findings as new data becomes available, ensuring that our research reflects the most accurate and current understanding of these complex atmospheric interactions.
10. Pure and Applied Geophysics, Springer Nature Switzerland AG
https://doi.org/10.1007/s00024-024-03481-5
Integrated Measurements of Particle Fluxes, Electric Fields, and Lightning Occurrences at the Aragats Space-Environmental Center (ASEC)
Authors: A. Chilingarian, T. Karapetyan, B. Sargsyan, Y. Khanikyanc, S. Chilingaryan
Most Cited CRD Papers (17 April 2024)
KASCADE Experiment
- "KASCADE measurements of energy spectra for elemental groups of cosmic rays: Results and open problems"
Authors: T. Antoni, W.D. Apel, A.F. Badea, K. Bekk, A. Bercuci, J. Blümer, H. Bozdog, et al.
Journal: Astroparticle Physics, Vol. 24, Issues 1-2, Pages 1-25
Citations: 865 - "A non-parametric approach to infer the energy spectrum and the mass composition of cosmic rays"
Authors: T. Antoni, W.D. Apel, F. Badea, K. Bekk, K. Bernlöhr, H. Blümer, E. Bollmann, et al.
Journal: Astroparticle Physics, Vol. 16, Issue 3, Pages 245-263
Citations: 110
MAGIC Experiment
- "Variable very high energy γ-ray emission from Markarian 501"
Authors: J. Albert, E. Aliu, H. Anderhub, P. Antoranz, A. Armada, C. Baixeras, J.A. Barrio, et al.
Journal: The Astrophysical Journal, Vol. 669, Issue 2, Page 862
Citations: 760
Aragats Experiments and Data Analysis Papers
- "Methods for multidimensional event classification: a case study using images from a Cherenkov gamma-ray telescope"
Authors: R.K. Bock, A. Chilingarian, M. Gaug, F. Hakl, T. Hengstebeck, M. Jiřina, et al.
Journal: Nuclear Instruments and Methods in Physics Research Section A: Accelerators, Spectrometers, Detectors and Associated Equipment
Citations: 327 - "Ground-based observations of thunderstorm-correlated fluxes of high-energy electrons, gamma rays, and neutrons"
Authors: A. Chilingarian, A. Daryan, K. Arakelyan, A. Hovhannisyan, B. Mailyan, et al.
Journal: Physical Review D, Vol. 82, Issue 4, Article 043009
Citations: 279 - "Particle bursts from thunderclouds: Natural particle accelerators above our heads"
Authors: A. Chilingarian, G. Hovsepyan, A. Hovhannisyan
Journal: Physical Review D, Vol. 83, Issue 6, Article 062001
Citations: 155 -
"Correlated measurements of secondary cosmic ray fluxes by the Aragats Space-Environmental Center monitors"
Authors: A. Chilingarian, K. Arakelyan, K. Avakyan, V. Babayan, N. Bostanjyan, et al.
Journal: Nuclear Instruments and Methods in Physics Research Section A: Accelerators, Spectrometers, Detectors and Associated Equipment
Citations: 99
