This proposal requests support for the continued collection and analysis of multi-instrument data at the Longyearbyen, Svalbard Observatory. Instrumented with an all-sky camera, a meridian scanning photometer, riometer, induction and fluxgate magnetometers, this site is well suited for studies of the cusp and delineation of high latitude magnetospheric boundaries. The Longyearbyen observatory is unique in the northern hemisphere in lying on the dark side of the terminator at noon during northern winter. The sky is dark enough to allow optical observation from late October to early February. The site has been operated successfully for more than a decade. Studies of the multi instrument data helps provide a context for interpretation unavailable for single instrument measurements. While the magnetometers can be used to identify the station location with regard to the major high-latitude current systems, the optical instruments identify emissions associated with the various regions near the cusp. As yet, it is not clear what processes the emissions and associated geomagnetic pulsations represent; they may map boundaries or show the processes confined by magnetospheric boundaries. The larger question is the goal of this proposal. During this winter season, this campaign will allow us to study large scale features of the cusp region and their development in time. Associated with impulsive events at the magnetopause, arcs and waves are detected which require study before a positive identification can be made. When combined with satellite data, the data suite is sufficient to begin the process of identifying ionospheric signatures of auroral forms associated the the cusp.
