Optical auroral spectra obtained at the Skibotn Observatory

In October 2023, a spectrograph has been permanently installed at the Skibotn Observatory (Norway) in order to regularly monitor the auroral spectrum between ~ 400 and 700 nm with a time resolution of 30 seconds. Using a 300 lines/mm grating and a slit of 100 nm width, the wavelength resolution is approximately of 0.3 nm.  The instrument is pointing field-aligned. The characteristics of the instrument will be provided as well as examples of spectra obtained during quiet, moderate and strong geomagnetic conditions.  A relative flux calibration is currently under way and will be discussed as well.  This will allow the computation of line ratios or a comparison with synthetic spectra obtained using kinetic transport codes such as e.g. Transsolo. Both approaches will provide an estimate of the precipitating fluxes (for electrons but also possibly for protons). Later on we aim to provide a database of low resolution auroral spectra accessible to the community, which will nicely complement data obtained with the new EISCAT_3D radar located a few kilometers from the observatory and data from the other optical instruments located at the observatory itself.  We will also consider the possibility to obtain higher resolution spectra using a 1800 lines/mm grating during specific requested campaigns. This project is a joint collaboration between BIRA-IASB (Belgium), IPAG (France) and UiT (Norway).