Time sequences of Colaba (CLA) disturbance values ${\mathrm{dist}}_{\mathrm{CLA}}^{1859}\left(t_j\right)$, equation (4), from 17:00 September 1 to 12:00 September 3, 1859, UT: regular hourly measurements (blue), auxiliary measurements (orange) made during periods of disturbance, UT-boxcar averages (black), the time of an apparent gap in the auxiliary measurements (grey). The hourly average centred on 06:30 UT is shown with and without the extreme hourly disturbance value at 06:20 UT. This figure can be compared with Hayakawa et al. (2022a). SC denotes sudden commencement; Gap denotes possible location of a data gap.