Time for another minor version update. We have addressed two issues in this latest release.
1) There was an error in how the Rx1day and Rx5day data were being handled for one of the West African data sources (January was being used in place of the Annual values). We have fixed this, which also ensures that the monthly values for these indices are also carried through to the final grids. You can see the difference in the resulting trends for this region in the two maps in Figure 1a & 1b, though there are only very small changes in the global annual trends.
|(a) HadEX 3.0.2 Rx1day trends|
|(b) HadEX 3.0.3 Rx1day trends|
2) In this latest update we have included information from some of the flags set in GHCND when converting these daily observations in preparation for calculating the indices. We cannot remember whether the previous functionality was intentional or if the flags had been ignored inadvertently. We now set observations which have failed the bounds check ("X"), the streak/frequent value check ("K") and the duplicate check ("D") as missing. For some indices the HadEX QC would have picked up e.g. the bounds check, but not for all. Keeping real extremes is clearly important in this case. Therefore, we have decided to use only these tests as we wanted to remove only those observations which are clearly erroneous and would have an impact on the indices.
For the gridded fields, this change makes very little difference, as the blending between stations performed by the Angular Distance Weighting algorithm smooths out the effect of erroneous values (as can be seen [or not!] in Figure 1). However around an extra 20 stations are now included in the gridded fields as these no longer fail our own QC. For users of the station data, these changes will be apparent.