Quiet, discrete auroral arcs are an important and fundamental consequence of solar wind-
magnetosphere interaction. We summarize the current standing of observations of such …

The Sun is a variable active-dynamo star, emitting radiation in all wavelengths and solar-
wind plasma to the interplanetary space. The Earth is immersed in this radiation and solar …

We have developed new Fabry-Perot interferometers (FPIs) that are designed to measure
thermospheric winds and temperatures as well as mesospheric winds through the …

A thermospheric wind data set from a Fabry‐Perot interferometer (630 nm) and the ion
velocity from a Dynasonde in Tromsø, Norway, was analyzed for nine winter seasons to …

Ion drag associated with the ionospheric plasma convection plays an important role in the
high-latitude thermospheric dynamics, yet changes in the thermospheric wind with …

Solar cycles 24–25 were quiet until a geomagnetic storm with a Sym‐H index of− 170 nT
occurred in late March 2023. On March 23–24, a Fabry‐Perot interferometer (FPI; 630 nm) in …

We examined the thermospheric and ionospheric responses to the solar flare on 28 October
2003, utilizing simultaneous observations of the electron and neutral density from the …

In the auroral E‐region strong electric fields can create an environment characterized by fast
plasma drifts. These fields lead to strong Hall currents which trigger small‐scale plasma …

This paper presents the first direct empirical evidence that mesoscale variations in ion
velocities must be taken into consideration when calculating Joule heating and relating it to …

Neutral winds are one of the most critical measurements in the lower thermosphere and E
region ionosphere (LTEI) for understanding complex electrodynamic processes and ion …