ISSN 2070-7401 (Print), ISSN 2411-0280 (Online)
Sovremennye problemy distantsionnogo zondirovaniya Zemli iz kosmosa


Sovremennye problemy distantsionnogo zondirovaniya Zemli iz kosmosa, 2020, Vol. 17, No. 5, pp. 286-290

Semi-annual variation of cosmic rays and ionosphere

V.L. Yanchukovsky 1 , A.Yu. Belinskaya 1 
1 Trofimuk Institute of Petroleum Geology and Geophysics SB RAS, Novosibirsk, Russia
Accepted: 26.10.2020
DOI: 10.21046/2070-7401-2020-17-5-286-290
The semi-annual component of the seasonal variation of the critical frequency of the ionosphere layer F2 (foF2) and the semi-annual variation in the intensity of cosmic (CR) rays are considered. The analysis used ionospheric observations at mid-latitude stations of the Southern Mauson (code MW26P, 62.9 S, 62.9 E) and Northern Novosibirsk (code NS355, 54.6° N, 83.2° E) hemispheres and neutron data monitors of the network of the Northern (Novosibirsk, Irkutsk, Moscow, Oulu) and Southern (Hermanus, Potchefstroom, Sanae, Tsumeb) hemispheres for the period from 1969 to 2019. A semi-annual variation of the ionosphere foF2 parameter was revealed. It repeats a six-month variation in the intensity of cosmic rays. The main reason for the appearance of a semi-annual variation in the CR intensity is the presence of a neutral heliosphere layer. The reason for this variation in the parameters of the ionospheric layer with maxima at the equinox and minima at the solstice is far from obvious. However, the experiment indicates that such a variation exists and is a semi-annual wave with an amplitude of about 20 %. A possible mechanism of its occurrence is proposed: it may be due to changes in the neutral gas of the upper atmosphere, which are caused by meteorological effects of the lower atmosphere, instigated by changes in the intensity of cosmic rays.
Keywords: cosmic rays, ionosphere, semi-annual variation
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