IONOSPHERIC EFFECTS OF MAGNETOPAUSE RECONNECTION OBSERVED USING IONOSPHERIC TOMOGRAPHY

This paper presents key signatures in the spatial distribution of iono spheric electron density attributed to solar wind particles injected f ollowing magnetopause reconnection. Using established criteria, optica l auroral emissions have been used to identify the reconnection proces s. A simultaneous image of electron density shows an enhanced region w ith a northward gradient in F-layer peak height that may be linked to dispersion of precipitating soft ions. In addition, an E-region enhanc ement at lower latitude can be associated with precipitation of pitch- angle scattered ring current electrons on closed field lines. A narrow density enhancement extending into the high topside ionosphere may in dicate the signature of a field-aligned current. Taken together, the f eatures enable identification in the ionosphere of the open/closed fie ld-line boundary.