Effect of near-earth thunderstorms electric field on the intensity of ground cosmic ray positrons/electrons in Tibet

Abstract

Monte Carlo simulations are performed to study the correlation between the ground cosmic ray intensity and near-earth thunderstorms electric field at YBJ (4300 m a.s.l., Tibet, China).The variations of the secondary cosmic ray intensity are found to be highly dependent on the strength and polarity of the electric field. In negative fields and in positive fields greater than 600 V/cm, the total number of ground comic ray positrons and electrons increases with increasing electric field strength. And these values increase more obviously when involving a shower with lower primary energy or a higher zenith angle. While in positive fields ranging from 0 to 600 V/cm, the total number of ground comic ray positrons and electrons declines and the amplitude is up to 3.1% for vertical showers. A decrease of intensity occurs in inclined showers within the range of 0−500 V/cm, which is accompanied by smaller amplitudes. In this paper, the intensity changes are discussed, especially concerning the decreases in positive electric fields. Our simulation results are in good agreement with ground-based experimental results obtained from ARGO-YBJ and the Carpet air shower array. These results could be helpful in understanding the acceleration mechanisms of secondary charged particles caused by an atmospheric electric field.

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

“…The dependence of TGEs on the sign of vertical component of electric field, found in our observations and previous study by Kudela et al (2017), was also discussed by Lidvansky (2003), Khaerdinov et al (2005) and Bartoli et al (2018). Bartoli et al (2018) analyzed observations in Tibet, China, at the altitude of 4300 m and performed simulations using CORSIKA code to investigate the development of secondary electrons and positrons following the hypothesis introduced by Zhou et al (2016). They conclude that the enhancements of secondary cosmic rays are more frequent for negative PG because of the initial abundance of electrons with respect to positrons in the Earth's atmosphere.…”

Correlations Between Secondary Cosmic Ray Rates and Strong Electric Fields at Lomnický štít

“…Clear asymmetry in polarity of E is indicated for the total electron/positron component. Although the altitude of LS is smaller than that for the position of Tibet CR station, Figure 5 of paper by Zhou et al () indicates about 65% of electrons and 35% of positrons in the total number of e + , e − component for zero electric field at the atmospheric depth of 600 g/cm 2 . Based on the curves in the cited figure, it is expected that the relative contribution of electrons is probably higher at the depth of LS (780 g/cm 2 ).…”

“…However, without knowledge of the electric field structure in the thunderstorm cloud, its position and motion with respect to the peak of Lomnický štít where the measurements are running, it is difficult to test such hypothesis. Thus, the suggested explanation of the asymmetry between number of events for negative and positive polarities of electric field, based on the theoretical paper by Zhou et al (), should be considered as one of possible hypotheses, which has to be confirmed by future investigations.…”

“…Because of the higher number of electrons than positrons, there is an asymmetry of percentage changes of electrons and positrons with respect to polarity of electric field. Figure 1 in Zhou et al () indicates that the percent change of the total sum (electrons plus positrons) is expected to increase especially due to the electron contribution at that altitude during the negative E polarity. Depression due to positrons is smaller than increase via the electrons for E < 0.…”

“…Because of the higher number of electrons than positrons, there is an asymmetry of percentage changes of electrons and positrons with respect to polarity of electric field. Figure 1 in Zhou et al (2016) indicates that the percent change of the total sum (electrons plus positrons) is expected to increase especially due to Figure 10. (first to fifth panels) The 2 min averages (raw count rate data), barometric pressure, data corrected for barometric pressure, filtered data (FFT high-pass filter at f > 2.5 × 10 À5 Hz), and relative humidity measured at LS.…”