A reversed plasma convection flow in the polar ionosphere observed with EISCAT radar

An abnormal anti-sunward intense flow of plasma convection is observed by EISCAT radar in the high-latitude ionosphere near the polar cap boundary. It occurred at morning sector of MLT under conditions of southward IMF B-z during the recovery phase of a moderate magnetic storm. A synthetic analysis of radar data and in-situ satellite observations is made in combination with a tracing of magnetic field lines by means of magnetospheric field model on this event. It is evidently indicated that the abnormal reversed westward flow of plasma convection and the features of the plasma structure and property are probably the ionospheric signatures of magnetic reconnection taking place at the dayside magnetopause.