Powerful radio waves transmitted into the ionosphere from the ground were used to study electron energization in the pumped ionospheric plasma turbulence, by detecting optical emissions from atomic oxygen. Our results obtained with the EISCAT (European Incoherent Scatter Scientific Association) facilities in northern Norway and optical detection with the ALIS (Auroral Large Imaging System) in northern Sweden suggest that long-wavelength upper hybrid waves are important in accelerating electrons.

Temperatures at 85 km around Earth's poles in summer can be so cold that small ice particles form. These can become charged, and, combined with turbulence at these altitudes, they can influence the many electrons present. This can cause large radar echoes called polar mesospheric summer echoes. We use radio waves to heat these echoes on and off when the sun is close to or below the horizon. This allows us to gain some insight into these ice particles and how the sun influences the echoes.

Ozone (O₃) is an important trace gas in the mesosphere and lower thermosphere (MLT), affecting heating rates and chemistry. O₃ profiles measured by the Ny-Ålesund Ozone in the Mesosphere Instrument agree with Sounding of the Atmosphere using Broadband Emission Radiometry (SABER) for winter night-time, but autumn twilight SABER abundances are up to 50 % higher. O₃ abundances in the MLT from two different SABER channels also show significant differences for both autumn twilight and summer daytime.

The polar mesospheric summer echoes (PMSE) are very strong radar echoes observed in the frequency range of 2 MHz up to 1 GHz. Such radar echoes are attributed to the ice clouds formed in the mesosphere and are widely believed to link to global climate change. PMSEs are coherent echoes produced by plasma density fluctuations at half the radar wavelengts. This paper investigates the unresolved problem of short durability of plasma fluctuations at smaller wavelengths in upper atmospheric physics.

We provide an explanation for mysterious radar echoes that look like increases in electron density during incoherent scatter radar measurements made when a high-power high-frequency (4–8 MHz) radio wave is transmitted up into the ionosphere. These echoes are seen at heights from about 200 to 650 km. We suggest that radar echoes at 930 MHz are guided along the earth's magnetic field by electron density irregularities created by the powerful radio wave, similar to light in an optical fibre.