Fig. 1From: Relationship between wave-like auroral arcs and Pi2 disturbances in plasma sheet prior to substorm onsetThe sequence of SNKQ ASI auroral images shows the evolution of substorm auroral expansion with substorm onset at ~0404:30 UT on 26 Feb. 2008. The white dots in these images indicate the fieldline footprints of the Th D and Th E spacecraft locations mapped by using the T96 modelBack to article page