Supporting Information for the journal paper: Rogers et al. "Improving the twilight model for polar cap absorption nowcasts", Space Weather, 2016.

This supporting information provides measurements from the Natural Resources Canada (NRCan) riometers, which were used in Section 3.5 of the paper. The original NRCan riometer data (at 1-second intervals) is available on request from Donald.Danskin@Canada.ca. The time series in dataset S1 are the medians of the absorption values (dB) in 5-minute periods for each NRCan riometer for the duration of the solar proton event in March 2012.

Each sheet of this Microsoft Excel workbook contains cosmic noise absorption measurements for a single NRCan riometer. The sheet name gives the riometer code corresponding to the locations mapped in Figure 1 of the paper (e.g. ale = Alert, ykc = Yellowknife, etc.), and the serial number of the riometer (e.g. 1 or 2). Column A is the date and time (UT) corresponding to the beginning of each 5-minute period. Column B is the median cosmic noise absorption (in dB at 30 MHz) in each 5-minute period.