Networks of people and infrastructure for ground-based auroral research

Ground-based optical instruments are very powerful tools for research on the aurora. When operated in networks they become even more powerful. Geographically distributed imagers are used to get an overview of the aurora and for tomography-like inversion. Existing networks include MIRACLE, the THEMIS all-sky imaging array and ALIS. Imagers with different fields of view can be used for studies of phenomena involving different scales including the so far little studied electron scale. It is favourable to combine ground-based optical instruments with other types of ground-based instruments as well as with satellites. The Kjell Henriksen Observatory in Svalbard is a good example of a coordinated infrastructure. Svalbard is well located for studies of the dayside aurora while northern Fennoscandia is well located for the nightside aurora. In Europe optical instruments are owned and operated by many small but dedicated groups, usually with little funding. Networking between groups is necessary to achieve networking between instruments. During IPY a network named International network for auroral optical studies was formed. The Nordic Council of Ministers finances the Network for Ground-based Optical Auroral Research in the Arctic Region. GAIA, Global Auroral Imaging Access, is a system to make optical data readily available. There are a number of ongoing initiatives to enhance networking between both instruments and people. SIOS on Svalbard aims to build infrastructure covering marine, terrestrial, atmospheric and space science. In Sweden a proposal has been submitted for planning of an integrated ground-based infrastructure for space and ionospheric research that will work in addition to the EISCAT radars, as well as with the proposed new EISCAT_3D facility. The Annual European Meetings for Atmospheric Studies by Optical Methods are excellent fora for discussing the networks including their international context.