The purpose of the OASIS project (Observations of Airglow with Spectrometer and Imager Systems) is to measure airglow in the mid-atmosphere at ca. 86 km altitude at the Paranal Observatory of the European Southern Observatory (ESO). Airglow can be used to characterize atmospheric dynamics at this otherwise almost inaccessible altitude level. This level is marked by diverse wave phenomena, like planetary waves, gravity waves and also infrasound, which are initiated in a variety of sources including global wind systems, storms and earthquakes.
Infrasound, for example, is initiated by earthquakes. Especially in Chile, which is located near two tectonic plate borders, earthquakes and seaquakes frequently occur. This pilot project accordingly has the goal of testing the capability to detect and characterize seaquakes in airglow, and particularly the tsunami that they can potentially trigger, ahead of time. If successful, this could be another element in providing early warning of tsunami, since it is often difficult to determine whether a seaquake has also generated a tsunami, or not.
At the same time, the instruments in Chile also supply important information for better understanding the gravity waves that are generated by mountain ranges. The measurements in the Andes thus ideally complement our over ten years of observations in the Alpine region. Information about these wave phenomena can help to further our understanding and quantification of climate signals, and possibly improve forecasting.
As part of a cooperation agreement with ESO, a container containing two cameras and a spectrometer system along with the associated equipment is to be transported to Chile in the Atacama desert. There, directly at the foot of the VLT (Very Large Telescope), there are ideal viewing conditions for the mentioned investigations. In addition, airglow measurements can be used to augment astronomical measurements with additional information, because the airglow level and especially its variability in the near-infrared range has to be taken into account for a clear view of the stars.