Significant enhancements of secondary cosmic rays and electric field at the high mountain peak of Lomnický Štít in High Tatras during thunderstorms

0522381 - ÚFA 2020 RIV DE eng J - Journal Article
Chum, Jaroslav - Langer, Ronald - Baše, Jiří - Kollárik, M. - Strhárský, I. - Diendorfer, G. - Rusz, Jan
Significant enhancements of secondary cosmic rays and electric field at the high mountain peak of Lomnický Štít in High Tatras during thunderstorms.
Earth, Planets and Space. Roč. 72, č. 1 (2020), č. článku 28. E-ISSN 1880-5981
R&D Projects: GA ČR(CZ) GA18-01969S; GA MŠMT EF15_003/0000481
Grant - others:AV ČR(CZ) SAV-18-04; Slovak Academy of Sciences(SK) VEGA 2/0155/18
Program: Bilaterální spolupráce; Kozmické energetické častice zo slnečných erupcií – mnohobodové pozorovanie od Slnka až po Lomnický Štít
Institutional support: RVO:68378289 ; RVO:61389005
Keywords : Thunderstorm ground enhancements of secondary cosmic ray flux * Gamma-ray glows * Neutron monitor * Electron acceleration * Particle detectors * Extreme event * Photonuclear reactions
OECD category: Fluids and plasma physics (including surface physics); Meteorology and atmospheric sciences (UJF-V)
Impact factor: 2.363, year: 2020
Method of publishing: Open access
https://earth-planets-space.springeropen.com/articles/10.1186/s40623-020-01155-9#Abs1

High electric fields that occur in thunderstorm clouds in the Earth’s atmosphere might accelerate energetic charged particles produced by cosmic rays. Such energetic particles, especially electrons, can cause additional ionization as they are multiplied and thus form avalanche of relativistic electrons. These relativistic electrons emit Bremsstrahlung in the X- or gamma-ray spectral ranges as they lose their kinetic energy via collisions. Thunderstorm ground enhancements (TGEs) of secondary cosmic ray fluxes recorded at the top of a sharp rocky mountain of Lomnický Štít in High Tatras (2634 m, Slovak Republic) are compared with simultaneous measurements of electric field at the mountain top and on its slope at the observatory of Skalnaté Pleso (1780 m). Results of measurements performed from May to September in 2017 and from May to October in 2018 are presented. The cosmic ray flux is measured by Space Environment Viewing and Analysis Network (SEVAN) and by neutron monitor with 1-s resolution. The TGEs that persisted usually several minutes were mainly detected in the SEVAN channel 1 which has the lowest energy threshold, about 7–8 MeV. A statistical analysis shows that these enhancements usually occurred (not only) during large values of vertical, upward-pointing electric fields measured just above the detector. It is shown that the measurement of electric field at Skalnaté Pleso, distant about 1.86 km from the mountain top is also partly correlated with the enhancements and can provide additional useful information about the distance or dimension of charge structure and dynamics of electric field, especially on short time scales. The enhancements usually did not exceed several tens of percent of background values. However, events that exceeded the background values several times were also recorded. The most extreme event exceeded the background values about 215 times. This event was also detected by other SEVAN channels and by the neutron monitor (~ 130% enhancement), which indicates a possibility of photonuclear reactions. The enhancements were often terminated by a nearby lightning.
Permanent Link: http://hdl.handle.net/11104/0307181