Hello,
I have a question about the specification of area_type in the CF Convention and its usage in CMIP5 -- motivated by the need to define how it might be used in CMIP6.
The convention document appears clear: "Some standard names (e.g. region and area_type) are used to indicate quantities which are permitted to take only certain standard values. This is indicated in the definition of the quantity in the standard name table, accompanied by a list or a link to a list of the permitted values." (section 3.3) In the case of "area_type", values must be taken from the area_type table.
In the CMIP5 variable request, however, the "landCoverFrac" variable is defined to have a dimension with standard name "area_type" that takes values corresponding to the model land cover scheme. Consequently, files have been submitted using terminology chosen by the data providers (e.g. "Temperate_Evergreen", "Temperate_Deciduous" in landCoverFrac_Lmon_MIROC-ESM_historical_r1i1p1_185001-200512.nc). Such files are clearly inconsistent with the convention but they appear to be passed by the CF checker (
http://puma.nerc.ac.uk/cgi-bin/cf-checker.pl ).
For CMIP6 we want to have compliant files, of course, but in practise we can only hope to have compliance where there is an automated check. So should we treat the rule about area_type only taking values from the approved list as a recommendation, or should the checker and the CMIP request be adjusted to comply with the existing wording? (Or have I completely misread something?)
regards,
Martin
Received on Fri Mar 20 2015 - 04:09:51 GMT
