Notes from a discussion of Jeff, Annette and Jonathan on 14th August 2007 about xancil for making dumps
Jeff has made some progress and we clarified the uses of xancil for making dumps. Since we first discussed it, we have changed our minds a bit. The user will provide xancil with an input dump, and one or more netCDF files. Individual fields from the input dump are copied to the output dump, replaced with data from one of the netCDF files, or ignored; the choice is specified field by field in a panel of xancil. Replacement fields are identified in the netCDF input by standard name. xancil can check that all the fields have the same grid, and optionally adjust them, but by default would give an error if they don’t. It can also check that 3D fields have the same vertical levels. For replacement ocean fields, the layer thicknesses can be found in the boundaries of the vertical coordinate in the CF netCDF. The ocean mask is indicated by a field chosen by the user. xancil can deduce the number-of-levels arrays, and can add the wrap-round columns, but may need information to be supplied for the island boxes.
The user can also provide additional fields to be added to the dump. For these, the user will have to specify the stash code to be assigned to each variable required. If xancil were able to read user stashmaster files, it would be able to help with this by offering a panel of extra prognostics to be added by name, and could then also check the new data was on the right grid (i.e. as specified by the stashmaster definition). New ocean fields would have to be supplied with wrap-round columns if required, or xancil would have to be told that they are needed.