The response of the middle ionosphere to the solar eclipse of 4 January 2011 in Kharkiv: some results of vertical sounding

1Chernogor, LF, 2Barabash, VV
1V.N. Karazin National University of Kharkiv, Kharkiv, Ukraine
2Institute of Ionosphere of National Academy of Sciences of Ukraine and Ministry of Education and Science of Ukraine, Kharkiv, Ukraine
Kosm. nauka tehnol. 2011, 17 ;(4):41-52
Publication Language: Russian
We describe our results of observations for the ionosphere dynamics at heights from 100 to 250 km during the partial (about 0.78) solar eclipse on 4 January 2011 near Kharkiv. The solar eclipse caused some modification of the ionosphere at all heights at first to the nightly conditions, and then to daily ones. The critical frequency of the F2-layer decreased by a factor of 2.1. The delay of these variations with respect to the main magnitude of the solar disk obscuration was equal to about 16 min. The virtual height of signal reflection near the maximum of the F2-layer ionization increased by 70 km, and the height of the model parabolic layer, hp, increased by 10 km. During the solar eclipse, some decrease in electron density and growth of quasi-periodic variations with periods of about 30 and 60 min are detected at all observable heights.
Keywords: electron density, solar eclipse, vertical sounding
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