Accounting for meteorological effects in the the detector of the charged component of cosmic rays

In this paper, we discuss the influence of meteorological effects on the data of the ground installation CARPET, which is a detector of the charged component of secondary cosmic rays (CRs). This device is designed in the P.N. Lebedev Physical Institute (LPI, Moscow, Russia) and installed at the Dolgoprudny scientific station (Dolgoprudny, Moscow region, S55.56 °, W37.3 °; Rc = 2.12 GV) in 2017. Based on the data obtained in 2019–2020, the barometric and temperature coefficients for the CARPET installation were determined. The barometric coefficient was calculated from the data of the barometric pressure sensor included in the installation. To determine the temperature effect, we used the data of upper-air sounding of the atmosphere obtained by the Federal State Budgetary Institution «Central Aerological Observatory» (CAO), also located in Dolgoprudny.

A wind effect of neutron component of cosmic rays at Antarctic station “Mirny”

Estimation of barometric coefficient for neutron component of cosmic rays was performed for Antarctic station Mirny taking into account effect of dynamic pressure caused by wind in the atmosphere. Hourly data of continue monitoring of neutron component and data of the local meteo station have been used for the period 2007-2014. Wind velocity at the observatory Mirny reaches 20-40 m/s in winter that corresponds to dynamic pressure of 5-6 mb and leads to the error of 5% in variations of neutron component because of dynamic effect in the atmosphere. The results are interesting for high latitude and high mountain detectors, where affect Bernulli may be significant.

Influence of the Atmospheric Mass on the High Energy Cosmic Ray Muons during a Solar Cycle

The rate of the detected cosmic ray muons depends on the atmospheric mass, height of pion production level, and temperature. Corrections for the changes in these parameters are importance to know the properties of the primary cosmic rays. In this paper, the effect of atmospheric mass, represented here by the atmospheric pressure, on the cosmic ray was studied using data from the KACST muon detector during the 2002–2012 period. The analysis was conducted by calculating the barometric coefficient (α) using regression analysis between the two parameters. The variation ofαover different time scales was investigated. The results revealed a seasonal cycle ofαwith a maximum in September and a minimum in March. Data from Adelaide muon detector were used, and different monthly variation was found. The barometric coefficient displays considerable variability at the interannual scale. Study of the annual variations ofαindicated cyclic variation with maximums between 2008 and 2009 and minimums between 2002 and 2003. This variable tendency is found to be anticorrelated with the solar activity, represented by the sunspot number. This finding was compared with the annual trend ofαfor the Adelaide muon detector for the same period of time, and a similar trend was found.

Barometric effect in low level counting

The correlation between the proportional counter and the barometric pressure was examined. The barometric coefficient was estimated by means of the regression line equation and the measured background was corrected according to the standard barometric pressure.

Effect of the Muon Contribution on the Barometric Coefficient of Neutron Monitors

The barometric coefficient of a cosmic-ray neutron monitor is found to increase with atmospheric depth from ~ 150 mm Hg to 600 mm Hg and then to decrease slowly with depth down to 760 mm Hg (Bachelet et al. 1965; Carmichael and Bercovitch 1969). Bachelet et al. 1965) tentatively attributed this change in the slope of the barometric coefficient versus atmospheric depth curve at 600 mm Hg to the contribution made by muons to the neutron monitor counting rate. Carmichael and Bercovitch (1969) have shown that the contribution to the monitor counting rate made by obliquely incident nucleons may be the real cause. Singh et al. (1970) have derived an expression for the barometric coefficient for vertically incident particles in a neutron monitor which increases continuously with increasing atmospheric depth down to 760 mm Hg, demonstrating more definitely that the above explanation of Carmichael and Bercovitch is correct.