Physical processes in the ionosphere during the solar eclipse on March 20, 2015 over Kharkiv, Ukraine (49.6° N, 36.3° E)

Abstract 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.