Physics of auroral phenomena : proceedings of the 37th Annual seminar, Apatity, 25 - 28 February, 2014 / [ed. board: A. G. Yahnin, N. V. Semenova]. - Апатиты : Изд-во Кольского научного центра РАН, 2014. - 125 с. : ил., табл.

Study o f the ionospheric irregularities It worth to note, that taking into account very quite space weather during experiment time (Dst index varied within limits of 10 nT, that not allow us to study storm-time ionosphere behavior, see Fig. 3), observed effects can be explained by increasing of ionosphere irregularities level caused by HF heating. These effects must be carefully studied in the future. The practical aspect of this investigation is a detailed study of nature and impact level of the ionospheric irregularities that can influence on the GPS/GLONASS performance especially at high latitudes and during disturbances and to obtain new knowledge that may improve the reliability of the global navigation systems in Arctic and Antarctic regions. Acknow ledgem ents. The authors are grateful to the EISCAT Scientific Association for operating time on the EISCAT facilities within the framework of Peer-reviewed Program. This study partially supported by RFBR 14-07- 00512 grant as well as RFBR grants #14-05-98820-sever. References Cherniak Iu.V., Lysenko V.N. (2012) Measurements of the ionosphere plasma electron density variation by the Kharkov Incoherent Scatter Radar. Acta Geophysica, AG-D-12-00045R1. Shagimuratov 1.1., Krankowski A., Ephishov I., Cherniak Iu., Wielgosz P., Zakharenkova I., (2012). High latitude TEC fluctuations and irregularity oval during geomagnetic storms. Earth, Planets and Space. Special Issue on IRI. V. 64, N. 6 , pp.521-529. 85