Noctilucent or "night-shining" clouds are tenuous ice clouds forming ~81 km over the Polar Regions during the summer months.

The atmospheric conditions that foster their growth are a result of the dynamic wave forcing and composition of this region. Noctilucent clouds (NLC) are at the limits of their existence, and changes in their density or occurrence rate have been cited as an early indicator of climate change.

The Aeronomy of Ice in the Mesosphere (AIM) satellite is a NASA mission on which NTNU is a co-investigator. It is the first satellite mission dedicated to the study of these clouds at the edge of space in order to understand what creates them, their variability and their possible connection to climate change.

At NTNU we are exploring how solar activity changes the atmospheric composition and dynamics in the vicinity of the NLC, and how this affects their formation. To do this, we combine the satellite measurements with the ground-based, remote-sensing observations of ozone and nitric oxide that we are making at Troll Station, Antarctica, in conjunction with the Norwegian Polar Institute and the British Antarctic Survey. This gives us a threedimensional picture of the atmospheric composition and the wave motions that impact the formation of NLC. By observing over a range of solar and auroral activity, we hope to see if these solar effects can enhance or mask the effects of global climate change on NLC.