The PIs will continue studying auroral arcs from Godhavn, Greenland. Simultaneously, incoherent scatter radar and optical instruments at Sondrestrom will view the same aurora. Overlapping fields from these two sites will provide a database for two dimensional measurement and tomographic description of auroral arcs in the magnetic meridian. The PI will also study auroral arcs and their thermospheric effects. The PI plans to operate a dedicated 'aeronomy' campaign each winter. Finally, he will analyze and publish results in the third year.***
