Novosibirsk, Russian Federation
Novosibirsk, Russian Federation
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.
cosmic rays, neutron monitor, meteorological effects, absorption range
1. Asatiani P.Ya., Blokh Ya.L., Gagua T.A. Large-size neutron counters, type SNM-15. Trudy vsesoyuznoy konferentsii po kosmicheskim lucham [Proceedings of the All-Union Conference on Cosmic Rays. Tashkent, 1968]. Moscow: Lebedev physical Institute Publ., 1969, pt. 2, iss. 3, pp. 101-104. (In Russian).
2. Heye B.R., Herrmann F., Jakobi J., Brogi C., Ilias A., Huisman J.A., Panagopoulos A., Pisinaras V. Monitoring of snowpack dynamics with cosmic-ray neutron probes: a comparison of four conversion methods. Front. Water. 04 August 2020. DOI:https://doi.org/10.3389/frwa.2020.00019.
3. Rivera Villarreyes C.A., Baroni G., Oswald S.E. Integral quantification of seasonal soil moisture changes in farmland by cosmic ray neutrons. Hydrology and Earth System Science. 2011, vol. 15, iss. 12, rr. 3843-3859. DOI:https://doi.org/10.5194/hess-15-3843-2011.
4. Dorman L.I. Meteorologicheskie effekty kosmicheskikh luchey [Meteorological Effects of Cosmic Rays]. Moscow, Nauka Publ., 1972, 210 p. (In Russian).
5. Dorman L.I. Experimentalnye i teoreticheskie osnovy astrofiziki kosmicheskikh luchey [Experimental and Theoretical Foundations of Cosmic Ray Astrophysics]. Moscow, Nauka Publ., 1975, 462 p. (In Russian).
6. GOST 14704-69. Laboratory balance. Weighing range and accuracy standards.
7. Kobelev P.G., Trefilova L.A., Belov A.V., Eroshenko E.A., Yanke V.G. Reference station method for eliminating snow effect based on data for 2018-2019. Fizika avroral’nykh yavleniy. Trudy XLII ezhegodnogo semenara. [Physics of Auroral Phenomena. Proc. XLII Annual Seminar]. Apatity, 2020, pp. 52-55. (In Russian).
8. Schattan P., Baroni G., Oswald S.E., Schöber J., Fey C., Kormann C., Huttenlau M., Achleitner S. Continuous monitoring of snowpack dynamics in alpine terrain by aboveground neutron sensing. Water Resources Research. 2017, vol. 53, iss. 5, rr. 3615-3634. DOI:https://doi.org/10.1002/2016WR020234.
9. Sigouin M.J.P., Si B.C. Calibration of a non-invasive cosmic-ray probe for wide area snow water equivalent measurement. The Cryosphere. 2016, vol. 10, rr. 1181-1190. DOI:https://doi.org/10.5194/tc-10-1181-2016.
10. Yanchukovsky V.L., Filimonov G.Ya. Coupling coefficients and atmospheric multiplicity of the neutron component of secondary cosmic rays. Izvestiya RAN. Seriya fizicheskaya [Bulletin of the Russian Academy of Sciences. Physics]. 1995, no 4, pp. 125-128. (In Russian).
11. URL: https://tehtab.ru/Guide/GuideMedias/GuideWater/SnowDensityAndHardness (accessed April 2, 2021).
12. URL: https://aliexpress.ru/item/32793950499.html?spm=a2g0s.9042311.0.0.3f7d33edMI6IXU&_ga=2.87447898.33769789.1614593370-424972838.1577095815&sku_id=6396517221 (accessed April 2, 2021).
