The electrified medium‐scale traveling ionospheric disturbances (EMSTIDs) occurring as geomagnetically conjugate features in the middle latitude F region ionosphere are studied using multi‐instrument observations. Airglow imaging of OI 630 nm emission over Sata, Japan, and Darwin, Australia, are used to identify the occurrence of EMSTIDs. Thermospheric wind measurements made with the Fabry‐Perot interferometer observations of OI 630 nm from Shigaraki, Japan, and Darwin, Australia, are used along with ionosonde observations over Yamagawa, Japan, and Darwin, Australia, to study the thermospheric and ionospheric characteristics. These are the first results from such multi‐instrument observations simultaneously made from geomagnetic conjugate locations. Our results show that the amplitudes of the EMSTIDs are often different between the hemispheres. Thermospheric meridional winds appear to control the EMSTID amplitudes in the respective hemisphere. However, EMSTIDs are generated only when there is significant sporadic E activity with foEs often reaching greater than 6 MHz and (foEs − fbEs) reaching above 5 MHz at least for a short duration occurred. Existence of strong sporadic E activity on one of the hemispheres is found to be sufficient enough for generation of EMSTIDs in the conjugate F regions. These results conclusively indicate the importance of sporadic E layers in the generation of EMSTIDs. Further, it shows the significance of interhemispheric coupling between the E and F region ionospheres in the formation of EMSTIDs while their amplitudes in the respective hemispheres appear to have control of thermospheric neutral winds in the same hemisphere.

Using the EquatorS spacecraft and Super-DARN HF radars an extensive survey of bursty reconnection at the magnetopause and associated¯ows in the polar ionosphere has been conducted. Flux transfer event (FTE) signatures were identi®ed in the EquatorS magnetometer data during periods of magnetopause contact in January and February 1998. Assuming the eects of the FTEs propagate to the polar ionosphere as geomagnetic ®eld-aligned-currents and associated Alfve n-waves, appropriate ®eld mappings to the ®eldsof-view of SuperDARN radars were performed. The radars observed discrete ionospheric¯ow channel events (FCEs) of the type previously assumed to be related to pulse reconnection. Such FCEs were associated with 80% of the FTEs and the two signatures are shown to be statistically associated with greater than 99% con®dence. Exemplary case studies highlight the nature of the ionospheric¯ows and their relation to the high latitude convection pattern, the association methodology, and the problems caused by instrument limitations.

Abstract. Using the Equator-S spacecraft and Super-DARN HF radars an extensive survey of bursty reconnection at the magnetopause and associated¯ows in the polar ionosphere has been conducted. Flux transfer event (FTE) signatures were identi®ed in the Equator-S magnetometer data during periods of magnetopause contact in January and February 1998. Assuming the e ects of the FTEs propagate to the polar ionosphere as geomagnetic ®eld-aligned-currents and associated Alfve n-waves, appropriate ®eld mappings to the ®elds-of-view of SuperDARN radars were performed. The radars observed discrete ionospheric¯ow channel events (FCEs) of the type previously assumed to be related to pulse reconnection. Such FCEs were associated with 80% of the FTEs and the two signatures are shown to be statistically associated with greater than 99% con®-dence. Exemplary case studies highlight the nature of the ionospheric¯ows and their relation to the high latitude convection pattern, the association methodology, and the problems caused by instrument limitations.

Magnetic field topologies between the Sun and Earth are important for the connectivity to Earth of solar suprathermal particles, e.g., solar energetic particles and beam electrons in type III solar radio bursts. An approach is developed for mapping large‐scale magnetic field lines near the solar equatorial plane, using near‐Earth observations and a solar wind model with nonzero azimuthal magnetic field at the source surface. Unlike Parker's spiral model, which restricts the in‐ecliptic angle ΦB in the Geocentric Solar Ecliptic coordinates to (90°–180°, 270°–360°) and so is unable to predict field configurations for the other ΦB values frequently observed in the solar wind, our approach can account for all the observed ΦB values. A set of predicted maps shows that near both minimal and maximal solar activity the field lines are typically open and that loops with both ends either connected to or disconnected from the Sun are relatively rare. The open field lines, nonetheless, often do not closely follow the Parker spiral, being less or more tightly wound, or strongly azimuthally or radially oriented, or inverted. The time‐varying classes, e.g., bidirectional electrons, of suprathermal electron pitch angle distributions (PADs) at 1 AU are predicted from the mapped field line configurations and compared with Wind observations for two solar rotations, one each near solar minimum and solar maximum. PAD predictions by our approach agree quantitatively (≈90%) with the PAD observations and outperform (by ≈20%) PAD predictions using Parker's model.