This study analyzes changes in the ionospheric response to solar flux over five complete solar cycles (1957 to 2023). We use Juliusruh hourly data of the peak electron density of the F2 layer, NmF2, and three solar extreme ultraviolet (EUV) radiation proxies. The response is better represented by a cubic regression, and F30 shows the highest correlation for describing NmF2 dependence over time. These results reveal a decrease in NmF2 influenced by the intensity of the solar activity index.

Investigation of winds is important to understand atmospheric dynamics. In the summer mesosphere and lower thermosphere, there are three main wind flows: the mesospheric westward, the mesopause southward (equatorward), and the lower-thermospheric eastward wind. Combining almost 2 decades of measurements from different radars, we study the trend, their interannual oscillations, and the effects of the geomagnetic activity over these wind maxima.

The geomagnetic and solar effect on Es is studied. The negative correlation between Es and geomagnetic activity at mid-latitude is related to the decreased meteor rate during storm period. The increased Es occurrence in high latitude relates to the changing electric field. The positive correlation between Es and solar activity at high latitude is due to the enhanced IMF in solar maximum. The negative correlation in mid and low latitudes relates to the decreased meteor rate during solar activity.

Little is known about the climate change of wind systems in the mesosphere and lower thermosphere at the edge of space at altitudes from 70–110 km. Meteor radars represent a well-accepted remote sensing technique to measure winds at these altitudes. Here we present a state-of-the-art climatological interhemispheric comparison using continuous and long-lasting observations from worldwide distributed meteor radars from the Arctic to the Antarctic and sophisticated general circulation models.

Submillimeter-Wave Limb-Emission Sounder 2 (SMILES-2) is a satellite mission proposed in Japan to probe the middle and upper atmosphere (20–160 km). The key products are wind, temperature and density. If selected, this mission could provide new insights into vertical coupling in the atmosphere and could help improve weather and climate models. We conducted simulation studies to assess the measurement performances in the altitude range 60–110 km, with a special focus on the geomagnetic effects.