No abstract

We have carried out an experimental study of the influence of precipitation in the form of snow on measurements of the neutron flux intensity near Earth's surface. We have examined the state of the snow cover and its density, and found out that the density depends on the depth of the snow cover. Using the experimental results, we estimate the neutron absorption path in the snow. Changes in snow cover by 10–12 cm at a depth of 80 cm are shown to cause variations in the monitor count rate with an amplitude of 0.9 %. At the snow depth of 80 cm, the neutron monitor count rate decreases by about 8 %. The observed variations should be attributed to the meteorological effects of cosmic rays. The absorption coefficient of neutrons in the snow was also found from the correlation between the count rate of the neutron monitor and the amount of snow above the detector. We propose a real-time correction of the neutron monitor data for precipitation in the form of snow. For this purpose, we implement continuous monitoring of the amount of snow cover. The monitoring is provided by a snow meter made using a laser rangefinder module. We discuss the results obtained.

Muons in the atmosphere are formed during the decay of pions resulting from nuclear interactions of cosmic rays with nuclei of air atoms. The resulting muons are also unstable particles with a short lifetime. Therefore, not all of them reach the level of observation in the atmosphere. When the atmospheric temperature changes, the distance to the observation level changes too, thus leading to variations in the intensity of muons of temperature origin. These variations, caused by atmospheric temperature variations, are superimposed on continuous observations of muon telescopes. Their exclusion is, therefore, extremely necessary, especially in the data from modern muon telescopes whose statistical accuracy is very high. The contribution of various atmospheric layers to the total temperature effect is not the same for muons. This contribution is characterized by the distribution of the density of temperature coefficients for muons in the atmosphere. Using this distribution and the continuous intensity observations from the muon telescope in Novosibirsk, the inverse problem has been solved, from the solution of which the atmospheric temperature variations over a long period from 2004 to 2011 have been found. The results obtained are compared with aerological sounding data.

________________________________________________________________________________The method of receiving vectors allows us to determine cosmic ray anisotropy at every moment of time.Also, the method makes it possible to study fast anisotropy fluctuations related to the interplanetary medium dynamics. Receiving vectors have been calculated earlier for neutron monitors and muon telescopes. However, most muon telescopes of the network of cosmic ray stations for which calculations were made does not operate now. In recent years, new, improved detectors have been developed.Unfortunately, the use of them is limited because of the absence of receiving coefficients. These detectors include a matrix telescope in Novosibirsk. Therefore, receiving vector components for muon telescopes of observation cosmic ray station Novosibirsk have been defined. Besides, design features of the facility, its orientation, and directional diagram depending on zenith and azimuth angles were taken into account.Also, for the system of telescopes, we allowed for coupling coefficients found experimentally by the test detector.

Muons in the atmosphere are formed during the decay of pions resulting from nuclear interactions of cosmic rays with nuclei of air atoms. The resulting muons are also unstable particles with a short lifetime. Therefore, not all of them reach the level of observation in the atmosphere. When the atmospheric temperature changes, the distance to the observation level changes too, thus leading to variations in the intensity of muons of temperature origin. These variations, caused by atmospheric temperature variations, are superimposed on continuous observations of muon telescopes. Their exclusion is, therefore, extremely necessary, especially in the data from modern muon telescopes whose statistical accuracy is very high. The contribution of various atmospheric layers to the total temperature effect is not the same for muons. This contribution is characterized by the distribution of the density of temperature coefficients for muons in the atmosphere. Using this distribution and the continuous intensity observations from the muon telescope in Novosibirsk, the inverse problem has been solved, from the solution of which the atmospheric temperature variations over a long period from 2004 to 2011 have been found. The results obtained are compared with aerological sounding data.