TY JOUR TI Ionospheric response to annular and partial solar eclipse of 29 April 2014 in Antarctica and Australian Regions KW Annular solar eclipse KW ionospheric parameters KW sporadic $E$ KW critical frequency JO Russian Journal of Earth Sciences AU Atulkar, R.. AU Khan, P.. AU Jeevakhan, H.. AU Purohit, P.K. PY 2015 IS 15 PB Geophysical Center of the Russian Academy of Sciences