annual indices based on part of the year are not seasonal
Currently they have to handled as seasonal to allow the season (i.e. relevant part of the year) to be specified. As result, the global variable frequency = "sem" rather than the correct frequency = "ann"
Could the code interpreting the metadata.yml entry
period:
allowed:
annual:
monthly:
seasonal: JASOND
default: seasonalbe changed to either output frequency = "ann" when there is just one entry (string) and not a list of strings, or to allow something like
period:
allowed:
annual: JASOND
monthly:
seasonal:
default: annual