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We present the results of observations of variations in the mid-latitude ionospheric parameters and physical processes in the geospace during March 20, 2015 partial solar eclipse over Kharkiv (49.60° N, 36.30° E) where the eclipse magnitude was about 0.54. The Kharkiv incoherent scatter (IS) radar and digital ionosonde were used for ionospheric observations and estimations of the parameters of the thermal and dynamical processes. At the time of the maximum obscuration of the Sun's area, an increase in the ionospheric F2 peak height by about 40 km was observed. At the same time, the electron density at altitudes of 190 and 210 km decreased by approximately 18.5 and 16.5%, respectively. During the eclipse, a decrease in the electron temperature and apparent changes in the vertical plasma drift velocity were observed. The observations and analysis have shown that the solar eclipse led to significant restructuring of the thermal and dynamic state of the ionospheric plasma over Kharkiv.

The results of calculations of dynamic and thermal processes in the geospace plasma during the partial solar eclipse of March 20, 2015 are presented. Also presented is a short review of studies devoted to the results of observations of the effects of several solar eclipses over Kharkiv within 1999 to 2011 according to the incoherent scatter radar data. For calculation of the dynamic and thermal processes in the ionosphere some basic theoretical ratios are presented. The calculations have showed that at the time of maximum coverage of the solar disk the absolute value of the vertical component of the plasma transport velocity by ambipolar diffusion increased by approximately 1 to 5 m/s. The full plasma flux density increased by approximately 20, 26 and 73 % at 250, 300 and 350 km. At the altitude of 400 km the it increased by about 1.2 times. The particle flux density due to ambipolar diffusion has increased by about 19 and 57 % at altitudes of 250 and 300 km, respectively. At the altitudes of 350 and 400 km the it increased by about 2 and 1.4 times as compared with the reference day of March 20, 2013. Calculations have showed that a significant change in the thermal mode of the ionosphere during solar eclipse took place. Thus, at the time of eclipse maximum phase there was a reduction in the energy supplied to electrons by about 30 to 35 % in the altitude range of 200 to 300 km. Also, the eclipse effects have well manifested in the variation of the heat flux density transferred by electrons from the plasmasphere into the ionosphere. At the moment of maximum coverage of the solar disk, its absolute value has decreased by about 63, 50 and 42 % at 300, 350 and 400 km, respectively.

УДК 550.385.4, 550.358:550.388 Приведены результаты расчетов эффектов возмущений теплового и динамического режимов верхней атмосферы Земли во время сильной магнитной бури 13–14 ноября 2012 г. Магнитная буря вызвала целый комплекс процессов, сопутствовавших возмущениям плазмы, электрических и магнитных полей в различных областях околоземного пространства. Подтверждено наличие в геомагнитных бурях как индивидуальных особенностей, так и общих закономерностей. Ключевые слова: геокосмическая буря, ионосферное возмущение, некогерентное рассеяние, динамические и тепловые процессы Статья поступила в редакцию 01.10.2014 Radio phys. radio astron. 2014, 19(4): 336-347 СПИСОК ЛИТЕРАТУРЫ 1. Домнин И. Ф., Емельянов Л. Я., Кацко С. В., Черногор Л. Ф. Ионосферные эффекты геокосмической бури 13–14 ноября 2012 г. // Радиофизика и радиоастрономия. – 2014. – Т. 19, № 2. – С. 170–180. 2. Черногор Л. Ф., Домнин И. Ф. Физика геокосмических бурь. – Харьков: ХНУ имени В. Н. Каразина, 2014. – 408 с. 3. Черногор Л. Ф. Физика Земли, атмосферы и геокосмоса в свете системной парадигмы // Радиофизика и радиоастрономия. – 2003. – Т. 8, № 1. – С. 59–106. 4. Григоренко Е. И., Пазюра С. А., Таран В. И., Черногор Л. Ф., Черняев С.В. Динамические процессы в ионосфере во время сильнейшей магнитной бури 30–31 мая 2003 г. // Геомагнетизм и аэрономия. – 2005. – Т. 45, № 6. – С. 803–823. 5. Salah J. E. and Evans J. V. Measurements of thermospheric temperature by incoherent scatter radar. In: Space Research XIII. – Berlin: Academie – Verlag, 1973. – P. 268–286. 6. Picone J. M., Hedin A. E., Drob D. P., and Aikin A. C. NRLMSISE-00 empirical model of the atmosphere: Statistical comparisons and scientific issues // J. Geophys. Res. Space Phys. – 2002. – Vol. 107, Is. A12. – P. SIA15-1–SIA15-16. 7. Бэнкс П. М. Тепловая структура ионосферы // ТИИЭР. – 1969. – Т. 57, № 3. – С. 6–30. 8. Schunk R. W. and Nagy A. F. Ionospheres: Physics, Plasma Physics, and Chemistry. – Cambridge, UK: Cambridge University Press, 2004. – 554 p. 9. Banks P. M. Charged particle temperatures and electron thermal conductivity in the upper atmosphere // Ann. Geophys. – 1966. – Vol. 22. – P. 577–584. 10. Dalgarno A. and Degges T. C. Electron cooling in the upper atmosphere // Planet. Space Sci. – 1968. – Vol. 16, Is. 1. – P. 125–127. 11. Сергеенко Н. П. Оценки электрических полей во время ионосферных возмущений. В кн.: Ионосферное прогнозирование. – М.: Наука, 1982. – С. 91–96. 12. Брюнелли Б. Е., Намгаладзе А. А. Физика ионосферы. – М.: Наука, 1987. – 528 с. 13. Домнин И. Ф., Емельянов Л. Я., Ляшенко М. В., Харитонова С. В., Черногор Л. Ф. Ионосферные процессы, сопровождавшие геокосмическую бурю 5–6 августа 2011 г. // Радиофизика и радиоастрономия. – 2012. – Т. 17, № 4. – С. 320–332. 14. Григоренко Е. И., Лысенко В. Н., Таран В. И., Черногор Л. Ф. Результаты радиофизических исследований процессов в ионосфере, сопровождавших сильнейшую геомагнитную бурю 25 сентября 1998 г. // Успехи современной радиоэлектроники. – 2003. – № 9. – С. 57–94. 15. Григоренко Е. И., Лазоренко С. В., Таран В. И., Черногор Л. Ф. Волновые возмущения в ионосфере, сопровождающие вспышку на Солнце и сильнейшую магнитную бурю 25 сентября 1998 г. // Геомагнетизм и аэрономия. – 2003. – Т. 43, № 6. – С. 770–787. 16. Кацко С. В., Домнин И. Ф., Емельянов Л. Я., Ляшенко М. В., Черногор Л. Ф. Ионосферная буря 5–6 августа 2011 г.: результаты расчетов основных эффектов // Радиофизика и радиоастрономия. – 2014. – Т. 19, № 1. – С. 26–39. 17. Данилов А. Д. Реакция области F на геомагнитные возмущения (обзор) // Гелиогеофизические исследования. – 2013. – № 5. – С. 1–33. 18. Пазюра С. А., Таран В. И., Черногор Л. Ф. Особенности ионосферной бури 4–6 апреля 2006 г. // Космічна наука і технологія. – 2008. – Т. 14, № 1. – С. 65–76. 19. Mansilla G. A. Mid-latitude effects of a great geomagnetic storm // J. Atmos. Sol.-Terr. Phys. – 2004. – Vol. 66, No. 12. – P. 1085–1091. 20. Mansilla G. A. Some effects in the upper atmosphere during geomagnetic storms // Adv. Space Res. – 2010. – Vol. 47, No. 6. – P. 930–937. 21. Sojka J. J., David M., Schunk R. W., and Heelis R. A. A modeling study of the longitudinal dependence of storm time midlatitude dayside total electron content enhancements // J. Geophys. Res. Space. Phys. – 2012. – Vol. 117, Is. A2. – id. A017000.

Calculation of dynamic and thermal processes parameters during the severe magnetic storm of August 5–6, 2011 (Kp max=8−) are presented. The magnetic storm was accompanied by negative ionospheric disturbance over Kharkiv which caused a number of changes in ionosphere. Plasma heating was observed during electron concentration depression in the F-layer which was accompanied by changes in neutral atmosphere composition and ionospheric dynamics.

The observation results of the effects in the geospace plasma during a partially (magnitude ∼0.42) solar eclipse are presented. The experimental data were obtained with an incoherent scatter radar of the Institute of the Ionosphere (near Kharkov). During the eclipse, the density at the F2 layer maximum decreased by 32%, the foF2 critical frequency decreased by 17.5%, and the altitude of the F2 layer maximum increased insignificantly. At altitudes of 290–680 km, the electron density decreased by ∼25%. During the eclipse, the electron and ion temperature decreased by 70–180 and 0–140 K, respectively, at altitudes of 190–490 km. Near the eclipse main phase, the plasma velocity vertical component decreased by 10–45 m/s at altitudes of 200–470 km, respectively. At the time of the eclipse main phase, the hydrogen ion fractional density increased by 50% as compared to the reference day at altitudes of 450–650 km.

The observations of the effects of the partial (about 77%) solar eclipse (SE) of March 29, 2006, in the ionospheric plasma are presented. The experimental data were obtained using the Kharkov incoherent scatter radar. At the moment of the maximum phase of SE, a decrease in the critical frequency of the ionospheric F2 layer by 18%, a depletion of the density in the F2 layer maximum by 33%, and an increase in the maximum height zm by 30 km were observed. The solar eclipse caused a decrease in the electron and ion temperatures by 150–300 and 100–200 K, respectively, within the height range 210–490 km. An increase in the relative density of the hydrogen ions during the maximum phase of SE by 20–25% within the height range 900–1200 km is detected. Calculations of the parameters of dynamical processes and thermal regime of the ionospheric plasma during SE are performed.

The modeling results of the zonal electric field and the vertical component of the plasma transfer velocity due to electromagnetic drift during August 5–6, 2011 and November 13–15, 2012 magnetic storms were presented. Confirmed that has a penetration of electric fields from magnetospheric origin in the mid-latitude ionosphere during strong geomagnetic disturbances. For the considered disturbed periods the neutral wind parameters were calculated using Kharkiv incoherent scatter radar data.