THERMAL AND DYNAMIC PROCESSES IN IONOSPHERE DURING PARTIAL SOLAR ECLIPSE OF MARCH 20, 2015 OVER KHARKIV: CALCULATION RESULTS

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.