MOESM3 of Relation of the auroral substorm to the substorm current wedge McPherronRobert ChuXiangning 2016 Additional file 3: Figure S3. Auroral luminosity on a north–south meridian over Fort Yukon as function of time. Keogram for Fort Yukon, NWT, Canada for the interval 08-10 UT is shown. Intense aurora was observed in association with fast flows at 08:56 and 09:38 UT. The first at 09:01:42 caused a poleward expansion. The next two appear to be effects of surges moving westward over the station.