(The data for this day in the wdc-like format is here.)

The number of stations used to derive the index is shown in color. The color scale is displayed at the right of the plot. Users should note that a loss of only one station could miss significant disturbance events.

Acknowledgments: We thank AE stations (Abisko [SGU, Sweden], Dixon Island, Cape Chelyuskin, Tixie Bay, Pebek [AARI, Russia], Barrow, College [USGS, USA], Yellowknife, Fort Churchill, Sanikiluaq (Poste-de-la-Baleine) [GSC, Canada], Narsarsuaq [DTU Space, Denmark], and Leirvogur [U. Iceland, Iceland]) as well as the RapidMAG team (NiCT, JHU/APL, UoA, AARI, and IDG) for their cooperations and efforts to operate these stations and to supply data with us for the provisional AE index.