These are supplementary data, as cited in Lewis, Wild, Allcock and Walach (2022), "Assessing the impact of weak and moderate geomagnetic storms on UK power station transformers", published in the journal "Space Weather".

The accompanying files include dissolved gas analysis records from coolant oil in 13 UK power station transformers for various timespans between 2010-2015. The dissolved gas analysis files are presented in comma separated variable format, one file for each of the 13 transformers. Each file includes a header line describing the content of each "column" of data. After this header, each line includes one record corresponding to the timestamp indicated in the first column (in Universal Time). Data are recorded in units of parts per million (ppm). With the exception of Transformers C and D, concentrations of 8 trace gases are recorded in each phase of the transformer. For Transformers C and D, concentrations of 8 trace gases are recorded in one phase only. The authors thank D. Barker, EDF Energy Nuclear Generation, for providing these data.

Also included is a file containing a list of geomagnetic storms in this period, an extended version of the list included in Walach & Grocott (2019) [https://doi.org/10.1029/2019JA026816]. The file presenting the list of geomagnetic storms is presented in a column-separated format, with a simple header row.

Please cite Lewis et al (2022) if using any of these data.