The plot shows D0 on 1903 October 30–November 2 of the reference stations, COI, CLA, CUA, and ZKW, as well as reconstructed Dst’ estimate. As the CLA magnetogram is scaled off at 9–10 h GMT, the Dst’ estimate in this period is reconstructed with data from three stations. Their background data are provided as data behind the figure.
(The data used to create this figure are available.)