By using two-dimensional optical images at 3914 ¿ and 5577 ¿ from the ISIS 2 satellite auroral imager, we have investigated the characteristics of auroras in the afternoon sector. The observed auroral configurations can be placed into three categories: diffuse aurora only, isolated discrete aurora, and discrete arcs connecting from the afternoon to the evening sector. Diffuse aurora only is observed when the By component of the interplanetary magnetic field is positive and no substorm processes are evident (Bz normally positive and AE values low). Isolated discrete features are observed when By is negative and are not dependent upon the presence of a substorm. The connected arcs category requires a substorm to have occurred with a pronounced westward electrojet. The average AE value of 240 &ggr; is a factor of 3 higher than for the diffuse or isolated caterogies. During the expansion phase of a substorm these connecting arcs are identified with the latitudinally confined westward electromet to the west of the auroral bulge.