Sub-auroral polarisation streams (SAPSs) are very fast plasma flows that occur at mid-latitudes, which can affect the atmosphere. In this paper, we use four ground-based radars to obtain a wide coverage of SAPSs that occurred over the USA, along with interferometer cameras in Virginia and Massachusetts to measure winds. The winds are strongly affected but in different ways, implying that the balance forces on the atmosphere is strongly dependent on proximity to the disturbance.

Magnetopause reconnection is a process whereby the Sun explosively transfers energy to the Earth. Whether the process is spatially patchy or spatially continuous and extended has been under long debate. We use space–ground coordination to overcome the limitations of previous studies and reliably interpret spatial extent. Our result strongly indicates that both patchy and extended reconnection is possible and, interestingly, that extended reconnection grows from a localized patch via spreading.

This is the first statistical study of the motion of patchy pulsating aurora (PPA). Our results show that PPA patches mainly drift eastward after midnight and westward before midnight, which suggests that the drifts of auroral patches could be a proxy for the ionospheric convection and provide a convenient and accurate method to remotely sense the magnetospheric convection. We also found that patch velocities do not seem to depend on AE index.

This paper reports the first experimental observation of stimulated Brillouin scattering near the third electron gyro-harmonic induced by high-frequency, high-power radio waves at EISCAT. The stimulated Brillouin scattering has also been correlated with simultaneous observations of the field-aligned irregularities and electron temperature. The observed stimulated Brillouin scattering becomes enhanced for pumping near electron gyro-harmonics.

A series of interplanetary coronal mass ejections in the period 7–17 March 2012 caused geomagnetic storms that strongly affected the high-latitude ionosphere in the Northern and Southern Hemisphere. Interhemispheric comparison of GPS phase scintillation reveals commonalities as well as asymmetries, as a consequence of the coupling between the solar wind and magnetosphere. The interhemispheric asymmetries are primarily caused by the dawn-dusk component of the interplanetary magnetic field.